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_CFS_BANDWIDTH
384 .procname
= "sched_cfs_bandwidth_slice_us",
385 .data
= &sysctl_sched_cfs_bandwidth_slice
,
386 .maxlen
= sizeof(unsigned int),
388 .proc_handler
= proc_dointvec_minmax
,
392 #ifdef CONFIG_PROVE_LOCKING
394 .procname
= "prove_locking",
395 .data
= &prove_locking
,
396 .maxlen
= sizeof(int),
398 .proc_handler
= proc_dointvec
,
401 #ifdef CONFIG_LOCK_STAT
403 .procname
= "lock_stat",
405 .maxlen
= sizeof(int),
407 .proc_handler
= proc_dointvec
,
412 .data
= &panic_timeout
,
413 .maxlen
= sizeof(int),
415 .proc_handler
= proc_dointvec
,
418 .procname
= "core_uses_pid",
419 .data
= &core_uses_pid
,
420 .maxlen
= sizeof(int),
422 .proc_handler
= proc_dointvec
,
425 .procname
= "core_pattern",
426 .data
= core_pattern
,
427 .maxlen
= CORENAME_MAX_SIZE
,
429 .proc_handler
= proc_dostring
,
432 .procname
= "core_pipe_limit",
433 .data
= &core_pipe_limit
,
434 .maxlen
= sizeof(unsigned int),
436 .proc_handler
= proc_dointvec
,
438 #ifdef CONFIG_PROC_SYSCTL
440 .procname
= "tainted",
441 .maxlen
= sizeof(long),
443 .proc_handler
= proc_taint
,
446 #ifdef CONFIG_LATENCYTOP
448 .procname
= "latencytop",
449 .data
= &latencytop_enabled
,
450 .maxlen
= sizeof(int),
452 .proc_handler
= proc_dointvec
,
455 #ifdef CONFIG_BLK_DEV_INITRD
457 .procname
= "real-root-dev",
458 .data
= &real_root_dev
,
459 .maxlen
= sizeof(int),
461 .proc_handler
= proc_dointvec
,
465 .procname
= "print-fatal-signals",
466 .data
= &print_fatal_signals
,
467 .maxlen
= sizeof(int),
469 .proc_handler
= proc_dointvec
,
473 .procname
= "reboot-cmd",
474 .data
= reboot_command
,
477 .proc_handler
= proc_dostring
,
480 .procname
= "stop-a",
481 .data
= &stop_a_enabled
,
482 .maxlen
= sizeof (int),
484 .proc_handler
= proc_dointvec
,
487 .procname
= "scons-poweroff",
488 .data
= &scons_pwroff
,
489 .maxlen
= sizeof (int),
491 .proc_handler
= proc_dointvec
,
494 #ifdef CONFIG_SPARC64
496 .procname
= "tsb-ratio",
497 .data
= &sysctl_tsb_ratio
,
498 .maxlen
= sizeof (int),
500 .proc_handler
= proc_dointvec
,
505 .procname
= "soft-power",
506 .data
= &pwrsw_enabled
,
507 .maxlen
= sizeof (int),
509 .proc_handler
= proc_dointvec
,
512 .procname
= "unaligned-trap",
513 .data
= &unaligned_enabled
,
514 .maxlen
= sizeof (int),
516 .proc_handler
= proc_dointvec
,
520 .procname
= "ctrl-alt-del",
522 .maxlen
= sizeof(int),
524 .proc_handler
= proc_dointvec
,
526 #ifdef CONFIG_FUNCTION_TRACER
528 .procname
= "ftrace_enabled",
529 .data
= &ftrace_enabled
,
530 .maxlen
= sizeof(int),
532 .proc_handler
= ftrace_enable_sysctl
,
535 #ifdef CONFIG_STACK_TRACER
537 .procname
= "stack_tracer_enabled",
538 .data
= &stack_tracer_enabled
,
539 .maxlen
= sizeof(int),
541 .proc_handler
= stack_trace_sysctl
,
544 #ifdef CONFIG_TRACING
546 .procname
= "ftrace_dump_on_oops",
547 .data
= &ftrace_dump_on_oops
,
548 .maxlen
= sizeof(int),
550 .proc_handler
= proc_dointvec
,
553 #ifdef CONFIG_MODULES
555 .procname
= "modprobe",
556 .data
= &modprobe_path
,
557 .maxlen
= KMOD_PATH_LEN
,
559 .proc_handler
= proc_dostring
,
562 .procname
= "modules_disabled",
563 .data
= &modules_disabled
,
564 .maxlen
= sizeof(int),
566 /* only handle a transition from default "0" to "1" */
567 .proc_handler
= proc_dointvec_minmax
,
572 #ifdef CONFIG_HOTPLUG
574 .procname
= "hotplug",
575 .data
= &uevent_helper
,
576 .maxlen
= UEVENT_HELPER_PATH_LEN
,
578 .proc_handler
= proc_dostring
,
581 #ifdef CONFIG_CHR_DEV_SG
583 .procname
= "sg-big-buff",
584 .data
= &sg_big_buff
,
585 .maxlen
= sizeof (int),
587 .proc_handler
= proc_dointvec
,
590 #ifdef CONFIG_BSD_PROCESS_ACCT
594 .maxlen
= 3*sizeof(int),
596 .proc_handler
= proc_dointvec
,
599 #ifdef CONFIG_MAGIC_SYSRQ
602 .data
= &__sysrq_enabled
,
603 .maxlen
= sizeof (int),
605 .proc_handler
= sysrq_sysctl_handler
,
608 #ifdef CONFIG_PROC_SYSCTL
610 .procname
= "cad_pid",
612 .maxlen
= sizeof (int),
614 .proc_handler
= proc_do_cad_pid
,
618 .procname
= "threads-max",
619 .data
= &max_threads
,
620 .maxlen
= sizeof(int),
622 .proc_handler
= proc_dointvec
,
625 .procname
= "random",
627 .child
= random_table
,
630 .procname
= "usermodehelper",
632 .child
= usermodehelper_table
,
635 .procname
= "overflowuid",
636 .data
= &overflowuid
,
637 .maxlen
= sizeof(int),
639 .proc_handler
= proc_dointvec_minmax
,
640 .extra1
= &minolduid
,
641 .extra2
= &maxolduid
,
644 .procname
= "overflowgid",
645 .data
= &overflowgid
,
646 .maxlen
= sizeof(int),
648 .proc_handler
= proc_dointvec_minmax
,
649 .extra1
= &minolduid
,
650 .extra2
= &maxolduid
,
653 #ifdef CONFIG_MATHEMU
655 .procname
= "ieee_emulation_warnings",
656 .data
= &sysctl_ieee_emulation_warnings
,
657 .maxlen
= sizeof(int),
659 .proc_handler
= proc_dointvec
,
663 .procname
= "userprocess_debug",
664 .data
= &show_unhandled_signals
,
665 .maxlen
= sizeof(int),
667 .proc_handler
= proc_dointvec
,
671 .procname
= "pid_max",
673 .maxlen
= sizeof (int),
675 .proc_handler
= proc_dointvec_minmax
,
676 .extra1
= &pid_max_min
,
677 .extra2
= &pid_max_max
,
680 .procname
= "panic_on_oops",
681 .data
= &panic_on_oops
,
682 .maxlen
= sizeof(int),
684 .proc_handler
= proc_dointvec
,
686 #if defined CONFIG_PRINTK
688 .procname
= "printk",
689 .data
= &console_loglevel
,
690 .maxlen
= 4*sizeof(int),
692 .proc_handler
= proc_dointvec
,
695 .procname
= "printk_ratelimit",
696 .data
= &printk_ratelimit_state
.interval
,
697 .maxlen
= sizeof(int),
699 .proc_handler
= proc_dointvec_jiffies
,
702 .procname
= "printk_ratelimit_burst",
703 .data
= &printk_ratelimit_state
.burst
,
704 .maxlen
= sizeof(int),
706 .proc_handler
= proc_dointvec
,
709 .procname
= "printk_delay",
710 .data
= &printk_delay_msec
,
711 .maxlen
= sizeof(int),
713 .proc_handler
= proc_dointvec_minmax
,
715 .extra2
= &ten_thousand
,
718 .procname
= "dmesg_restrict",
719 .data
= &dmesg_restrict
,
720 .maxlen
= sizeof(int),
722 .proc_handler
= proc_dointvec_minmax
,
727 .procname
= "kptr_restrict",
728 .data
= &kptr_restrict
,
729 .maxlen
= sizeof(int),
731 .proc_handler
= proc_dmesg_restrict
,
737 .procname
= "ngroups_max",
738 .data
= &ngroups_max
,
739 .maxlen
= sizeof (int),
741 .proc_handler
= proc_dointvec
,
743 #if defined(CONFIG_LOCKUP_DETECTOR)
745 .procname
= "watchdog",
746 .data
= &watchdog_enabled
,
747 .maxlen
= sizeof (int),
749 .proc_handler
= proc_dowatchdog
,
754 .procname
= "watchdog_thresh",
755 .data
= &watchdog_thresh
,
756 .maxlen
= sizeof(int),
758 .proc_handler
= proc_dowatchdog
,
763 .procname
= "softlockup_panic",
764 .data
= &softlockup_panic
,
765 .maxlen
= sizeof(int),
767 .proc_handler
= proc_dointvec_minmax
,
772 .procname
= "nmi_watchdog",
773 .data
= &watchdog_enabled
,
774 .maxlen
= sizeof (int),
776 .proc_handler
= proc_dowatchdog
,
781 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
783 .procname
= "unknown_nmi_panic",
784 .data
= &unknown_nmi_panic
,
785 .maxlen
= sizeof (int),
787 .proc_handler
= proc_dointvec
,
790 #if defined(CONFIG_X86)
792 .procname
= "panic_on_unrecovered_nmi",
793 .data
= &panic_on_unrecovered_nmi
,
794 .maxlen
= sizeof(int),
796 .proc_handler
= proc_dointvec
,
799 .procname
= "panic_on_io_nmi",
800 .data
= &panic_on_io_nmi
,
801 .maxlen
= sizeof(int),
803 .proc_handler
= proc_dointvec
,
806 .procname
= "bootloader_type",
807 .data
= &bootloader_type
,
808 .maxlen
= sizeof (int),
810 .proc_handler
= proc_dointvec
,
813 .procname
= "bootloader_version",
814 .data
= &bootloader_version
,
815 .maxlen
= sizeof (int),
817 .proc_handler
= proc_dointvec
,
820 .procname
= "kstack_depth_to_print",
821 .data
= &kstack_depth_to_print
,
822 .maxlen
= sizeof(int),
824 .proc_handler
= proc_dointvec
,
827 .procname
= "io_delay_type",
828 .data
= &io_delay_type
,
829 .maxlen
= sizeof(int),
831 .proc_handler
= proc_dointvec
,
834 #if defined(CONFIG_MMU)
836 .procname
= "randomize_va_space",
837 .data
= &randomize_va_space
,
838 .maxlen
= sizeof(int),
840 .proc_handler
= proc_dointvec
,
843 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
845 .procname
= "spin_retry",
847 .maxlen
= sizeof (int),
849 .proc_handler
= proc_dointvec
,
852 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
854 .procname
= "acpi_video_flags",
855 .data
= &acpi_realmode_flags
,
856 .maxlen
= sizeof (unsigned long),
858 .proc_handler
= proc_doulongvec_minmax
,
863 .procname
= "ignore-unaligned-usertrap",
864 .data
= &no_unaligned_warning
,
865 .maxlen
= sizeof (int),
867 .proc_handler
= proc_dointvec
,
870 .procname
= "unaligned-dump-stack",
871 .data
= &unaligned_dump_stack
,
872 .maxlen
= sizeof (int),
874 .proc_handler
= proc_dointvec
,
877 #ifdef CONFIG_DETECT_HUNG_TASK
879 .procname
= "hung_task_panic",
880 .data
= &sysctl_hung_task_panic
,
881 .maxlen
= sizeof(int),
883 .proc_handler
= proc_dointvec_minmax
,
888 .procname
= "hung_task_check_count",
889 .data
= &sysctl_hung_task_check_count
,
890 .maxlen
= sizeof(unsigned long),
892 .proc_handler
= proc_doulongvec_minmax
,
895 .procname
= "hung_task_timeout_secs",
896 .data
= &sysctl_hung_task_timeout_secs
,
897 .maxlen
= sizeof(unsigned long),
899 .proc_handler
= proc_dohung_task_timeout_secs
,
902 .procname
= "hung_task_warnings",
903 .data
= &sysctl_hung_task_warnings
,
904 .maxlen
= sizeof(unsigned long),
906 .proc_handler
= proc_doulongvec_minmax
,
911 .procname
= "compat-log",
913 .maxlen
= sizeof (int),
915 .proc_handler
= proc_dointvec
,
918 #ifdef CONFIG_RT_MUTEXES
920 .procname
= "max_lock_depth",
921 .data
= &max_lock_depth
,
922 .maxlen
= sizeof(int),
924 .proc_handler
= proc_dointvec
,
928 .procname
= "poweroff_cmd",
929 .data
= &poweroff_cmd
,
930 .maxlen
= POWEROFF_CMD_PATH_LEN
,
932 .proc_handler
= proc_dostring
,
938 .child
= key_sysctls
,
941 #ifdef CONFIG_RCU_TORTURE_TEST
943 .procname
= "rcutorture_runnable",
944 .data
= &rcutorture_runnable
,
945 .maxlen
= sizeof(int),
947 .proc_handler
= proc_dointvec
,
950 #ifdef CONFIG_PERF_EVENTS
952 * User-space scripts rely on the existence of this file
953 * as a feature check for perf_events being enabled.
955 * So it's an ABI, do not remove!
958 .procname
= "perf_event_paranoid",
959 .data
= &sysctl_perf_event_paranoid
,
960 .maxlen
= sizeof(sysctl_perf_event_paranoid
),
962 .proc_handler
= proc_dointvec
,
965 .procname
= "perf_event_mlock_kb",
966 .data
= &sysctl_perf_event_mlock
,
967 .maxlen
= sizeof(sysctl_perf_event_mlock
),
969 .proc_handler
= proc_dointvec
,
972 .procname
= "perf_event_max_sample_rate",
973 .data
= &sysctl_perf_event_sample_rate
,
974 .maxlen
= sizeof(sysctl_perf_event_sample_rate
),
976 .proc_handler
= perf_proc_update_handler
,
979 #ifdef CONFIG_KMEMCHECK
981 .procname
= "kmemcheck",
982 .data
= &kmemcheck_enabled
,
983 .maxlen
= sizeof(int),
985 .proc_handler
= proc_dointvec
,
990 .procname
= "blk_iopoll",
991 .data
= &blk_iopoll_enabled
,
992 .maxlen
= sizeof(int),
994 .proc_handler
= proc_dointvec
,
1000 static struct ctl_table vm_table
[] = {
1002 .procname
= "overcommit_memory",
1003 .data
= &sysctl_overcommit_memory
,
1004 .maxlen
= sizeof(sysctl_overcommit_memory
),
1006 .proc_handler
= proc_dointvec_minmax
,
1011 .procname
= "panic_on_oom",
1012 .data
= &sysctl_panic_on_oom
,
1013 .maxlen
= sizeof(sysctl_panic_on_oom
),
1015 .proc_handler
= proc_dointvec_minmax
,
1020 .procname
= "oom_kill_allocating_task",
1021 .data
= &sysctl_oom_kill_allocating_task
,
1022 .maxlen
= sizeof(sysctl_oom_kill_allocating_task
),
1024 .proc_handler
= proc_dointvec
,
1027 .procname
= "oom_dump_tasks",
1028 .data
= &sysctl_oom_dump_tasks
,
1029 .maxlen
= sizeof(sysctl_oom_dump_tasks
),
1031 .proc_handler
= proc_dointvec
,
1034 .procname
= "overcommit_ratio",
1035 .data
= &sysctl_overcommit_ratio
,
1036 .maxlen
= sizeof(sysctl_overcommit_ratio
),
1038 .proc_handler
= proc_dointvec
,
1041 .procname
= "page-cluster",
1042 .data
= &page_cluster
,
1043 .maxlen
= sizeof(int),
1045 .proc_handler
= proc_dointvec_minmax
,
1049 .procname
= "dirty_background_ratio",
1050 .data
= &dirty_background_ratio
,
1051 .maxlen
= sizeof(dirty_background_ratio
),
1053 .proc_handler
= dirty_background_ratio_handler
,
1055 .extra2
= &one_hundred
,
1058 .procname
= "dirty_background_bytes",
1059 .data
= &dirty_background_bytes
,
1060 .maxlen
= sizeof(dirty_background_bytes
),
1062 .proc_handler
= dirty_background_bytes_handler
,
1066 .procname
= "dirty_ratio",
1067 .data
= &vm_dirty_ratio
,
1068 .maxlen
= sizeof(vm_dirty_ratio
),
1070 .proc_handler
= dirty_ratio_handler
,
1072 .extra2
= &one_hundred
,
1075 .procname
= "dirty_bytes",
1076 .data
= &vm_dirty_bytes
,
1077 .maxlen
= sizeof(vm_dirty_bytes
),
1079 .proc_handler
= dirty_bytes_handler
,
1080 .extra1
= &dirty_bytes_min
,
1083 .procname
= "dirty_writeback_centisecs",
1084 .data
= &dirty_writeback_interval
,
1085 .maxlen
= sizeof(dirty_writeback_interval
),
1087 .proc_handler
= dirty_writeback_centisecs_handler
,
1090 .procname
= "dirty_expire_centisecs",
1091 .data
= &dirty_expire_interval
,
1092 .maxlen
= sizeof(dirty_expire_interval
),
1094 .proc_handler
= proc_dointvec_minmax
,
1098 .procname
= "nr_pdflush_threads",
1099 .data
= &nr_pdflush_threads
,
1100 .maxlen
= sizeof nr_pdflush_threads
,
1101 .mode
= 0444 /* read-only*/,
1102 .proc_handler
= proc_dointvec
,
1105 .procname
= "swappiness",
1106 .data
= &vm_swappiness
,
1107 .maxlen
= sizeof(vm_swappiness
),
1109 .proc_handler
= proc_dointvec_minmax
,
1111 .extra2
= &one_hundred
,
1113 #ifdef CONFIG_HUGETLB_PAGE
1115 .procname
= "nr_hugepages",
1117 .maxlen
= sizeof(unsigned long),
1119 .proc_handler
= hugetlb_sysctl_handler
,
1120 .extra1
= (void *)&hugetlb_zero
,
1121 .extra2
= (void *)&hugetlb_infinity
,
1125 .procname
= "nr_hugepages_mempolicy",
1127 .maxlen
= sizeof(unsigned long),
1129 .proc_handler
= &hugetlb_mempolicy_sysctl_handler
,
1130 .extra1
= (void *)&hugetlb_zero
,
1131 .extra2
= (void *)&hugetlb_infinity
,
1135 .procname
= "hugetlb_shm_group",
1136 .data
= &sysctl_hugetlb_shm_group
,
1137 .maxlen
= sizeof(gid_t
),
1139 .proc_handler
= proc_dointvec
,
1142 .procname
= "hugepages_treat_as_movable",
1143 .data
= &hugepages_treat_as_movable
,
1144 .maxlen
= sizeof(int),
1146 .proc_handler
= hugetlb_treat_movable_handler
,
1149 .procname
= "nr_overcommit_hugepages",
1151 .maxlen
= sizeof(unsigned long),
1153 .proc_handler
= hugetlb_overcommit_handler
,
1154 .extra1
= (void *)&hugetlb_zero
,
1155 .extra2
= (void *)&hugetlb_infinity
,
1159 .procname
= "lowmem_reserve_ratio",
1160 .data
= &sysctl_lowmem_reserve_ratio
,
1161 .maxlen
= sizeof(sysctl_lowmem_reserve_ratio
),
1163 .proc_handler
= lowmem_reserve_ratio_sysctl_handler
,
1166 .procname
= "drop_caches",
1167 .data
= &sysctl_drop_caches
,
1168 .maxlen
= sizeof(int),
1170 .proc_handler
= drop_caches_sysctl_handler
,
1174 #ifdef CONFIG_COMPACTION
1176 .procname
= "compact_memory",
1177 .data
= &sysctl_compact_memory
,
1178 .maxlen
= sizeof(int),
1180 .proc_handler
= sysctl_compaction_handler
,
1183 .procname
= "extfrag_threshold",
1184 .data
= &sysctl_extfrag_threshold
,
1185 .maxlen
= sizeof(int),
1187 .proc_handler
= sysctl_extfrag_handler
,
1188 .extra1
= &min_extfrag_threshold
,
1189 .extra2
= &max_extfrag_threshold
,
1192 #endif /* CONFIG_COMPACTION */
1194 .procname
= "min_free_kbytes",
1195 .data
= &min_free_kbytes
,
1196 .maxlen
= sizeof(min_free_kbytes
),
1198 .proc_handler
= min_free_kbytes_sysctl_handler
,
1202 .procname
= "percpu_pagelist_fraction",
1203 .data
= &percpu_pagelist_fraction
,
1204 .maxlen
= sizeof(percpu_pagelist_fraction
),
1206 .proc_handler
= percpu_pagelist_fraction_sysctl_handler
,
1207 .extra1
= &min_percpu_pagelist_fract
,
1211 .procname
= "max_map_count",
1212 .data
= &sysctl_max_map_count
,
1213 .maxlen
= sizeof(sysctl_max_map_count
),
1215 .proc_handler
= proc_dointvec_minmax
,
1220 .procname
= "nr_trim_pages",
1221 .data
= &sysctl_nr_trim_pages
,
1222 .maxlen
= sizeof(sysctl_nr_trim_pages
),
1224 .proc_handler
= proc_dointvec_minmax
,
1229 .procname
= "laptop_mode",
1230 .data
= &laptop_mode
,
1231 .maxlen
= sizeof(laptop_mode
),
1233 .proc_handler
= proc_dointvec_jiffies
,
1236 .procname
= "block_dump",
1237 .data
= &block_dump
,
1238 .maxlen
= sizeof(block_dump
),
1240 .proc_handler
= proc_dointvec
,
1244 .procname
= "vfs_cache_pressure",
1245 .data
= &sysctl_vfs_cache_pressure
,
1246 .maxlen
= sizeof(sysctl_vfs_cache_pressure
),
1248 .proc_handler
= proc_dointvec
,
1251 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1253 .procname
= "legacy_va_layout",
1254 .data
= &sysctl_legacy_va_layout
,
1255 .maxlen
= sizeof(sysctl_legacy_va_layout
),
1257 .proc_handler
= proc_dointvec
,
1263 .procname
= "zone_reclaim_mode",
1264 .data
= &zone_reclaim_mode
,
1265 .maxlen
= sizeof(zone_reclaim_mode
),
1267 .proc_handler
= proc_dointvec
,
1271 .procname
= "min_unmapped_ratio",
1272 .data
= &sysctl_min_unmapped_ratio
,
1273 .maxlen
= sizeof(sysctl_min_unmapped_ratio
),
1275 .proc_handler
= sysctl_min_unmapped_ratio_sysctl_handler
,
1277 .extra2
= &one_hundred
,
1280 .procname
= "min_slab_ratio",
1281 .data
= &sysctl_min_slab_ratio
,
1282 .maxlen
= sizeof(sysctl_min_slab_ratio
),
1284 .proc_handler
= sysctl_min_slab_ratio_sysctl_handler
,
1286 .extra2
= &one_hundred
,
1291 .procname
= "stat_interval",
1292 .data
= &sysctl_stat_interval
,
1293 .maxlen
= sizeof(sysctl_stat_interval
),
1295 .proc_handler
= proc_dointvec_jiffies
,
1300 .procname
= "mmap_min_addr",
1301 .data
= &dac_mmap_min_addr
,
1302 .maxlen
= sizeof(unsigned long),
1304 .proc_handler
= mmap_min_addr_handler
,
1309 .procname
= "numa_zonelist_order",
1310 .data
= &numa_zonelist_order
,
1311 .maxlen
= NUMA_ZONELIST_ORDER_LEN
,
1313 .proc_handler
= numa_zonelist_order_handler
,
1316 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1317 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1319 .procname
= "vdso_enabled",
1320 .data
= &vdso_enabled
,
1321 .maxlen
= sizeof(vdso_enabled
),
1323 .proc_handler
= proc_dointvec
,
1327 #ifdef CONFIG_HIGHMEM
1329 .procname
= "highmem_is_dirtyable",
1330 .data
= &vm_highmem_is_dirtyable
,
1331 .maxlen
= sizeof(vm_highmem_is_dirtyable
),
1333 .proc_handler
= proc_dointvec_minmax
,
1339 .procname
= "scan_unevictable_pages",
1340 .data
= &scan_unevictable_pages
,
1341 .maxlen
= sizeof(scan_unevictable_pages
),
1343 .proc_handler
= scan_unevictable_handler
,
1345 #ifdef CONFIG_MEMORY_FAILURE
1347 .procname
= "memory_failure_early_kill",
1348 .data
= &sysctl_memory_failure_early_kill
,
1349 .maxlen
= sizeof(sysctl_memory_failure_early_kill
),
1351 .proc_handler
= proc_dointvec_minmax
,
1356 .procname
= "memory_failure_recovery",
1357 .data
= &sysctl_memory_failure_recovery
,
1358 .maxlen
= sizeof(sysctl_memory_failure_recovery
),
1360 .proc_handler
= proc_dointvec_minmax
,
1368 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1369 static struct ctl_table binfmt_misc_table
[] = {
1374 static struct ctl_table fs_table
[] = {
1376 .procname
= "inode-nr",
1377 .data
= &inodes_stat
,
1378 .maxlen
= 2*sizeof(int),
1380 .proc_handler
= proc_nr_inodes
,
1383 .procname
= "inode-state",
1384 .data
= &inodes_stat
,
1385 .maxlen
= 7*sizeof(int),
1387 .proc_handler
= proc_nr_inodes
,
1390 .procname
= "file-nr",
1391 .data
= &files_stat
,
1392 .maxlen
= sizeof(files_stat
),
1394 .proc_handler
= proc_nr_files
,
1397 .procname
= "file-max",
1398 .data
= &files_stat
.max_files
,
1399 .maxlen
= sizeof(files_stat
.max_files
),
1401 .proc_handler
= proc_doulongvec_minmax
,
1404 .procname
= "nr_open",
1405 .data
= &sysctl_nr_open
,
1406 .maxlen
= sizeof(int),
1408 .proc_handler
= proc_dointvec_minmax
,
1409 .extra1
= &sysctl_nr_open_min
,
1410 .extra2
= &sysctl_nr_open_max
,
1413 .procname
= "dentry-state",
1414 .data
= &dentry_stat
,
1415 .maxlen
= 6*sizeof(int),
1417 .proc_handler
= proc_nr_dentry
,
1420 .procname
= "overflowuid",
1421 .data
= &fs_overflowuid
,
1422 .maxlen
= sizeof(int),
1424 .proc_handler
= proc_dointvec_minmax
,
1425 .extra1
= &minolduid
,
1426 .extra2
= &maxolduid
,
1429 .procname
= "overflowgid",
1430 .data
= &fs_overflowgid
,
1431 .maxlen
= sizeof(int),
1433 .proc_handler
= proc_dointvec_minmax
,
1434 .extra1
= &minolduid
,
1435 .extra2
= &maxolduid
,
1437 #ifdef CONFIG_FILE_LOCKING
1439 .procname
= "leases-enable",
1440 .data
= &leases_enable
,
1441 .maxlen
= sizeof(int),
1443 .proc_handler
= proc_dointvec
,
1446 #ifdef CONFIG_DNOTIFY
1448 .procname
= "dir-notify-enable",
1449 .data
= &dir_notify_enable
,
1450 .maxlen
= sizeof(int),
1452 .proc_handler
= proc_dointvec
,
1456 #ifdef CONFIG_FILE_LOCKING
1458 .procname
= "lease-break-time",
1459 .data
= &lease_break_time
,
1460 .maxlen
= sizeof(int),
1462 .proc_handler
= proc_dointvec
,
1467 .procname
= "aio-nr",
1469 .maxlen
= sizeof(aio_nr
),
1471 .proc_handler
= proc_doulongvec_minmax
,
1474 .procname
= "aio-max-nr",
1475 .data
= &aio_max_nr
,
1476 .maxlen
= sizeof(aio_max_nr
),
1478 .proc_handler
= proc_doulongvec_minmax
,
1480 #endif /* CONFIG_AIO */
1481 #ifdef CONFIG_INOTIFY_USER
1483 .procname
= "inotify",
1485 .child
= inotify_table
,
1490 .procname
= "epoll",
1492 .child
= epoll_table
,
1497 .procname
= "suid_dumpable",
1498 .data
= &suid_dumpable
,
1499 .maxlen
= sizeof(int),
1501 .proc_handler
= proc_dointvec_minmax
,
1505 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1507 .procname
= "binfmt_misc",
1509 .child
= binfmt_misc_table
,
1513 .procname
= "pipe-max-size",
1514 .data
= &pipe_max_size
,
1515 .maxlen
= sizeof(int),
1517 .proc_handler
= &pipe_proc_fn
,
1518 .extra1
= &pipe_min_size
,
1523 static struct ctl_table debug_table
[] = {
1524 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1525 defined(CONFIG_S390) || defined(CONFIG_TILE)
1527 .procname
= "exception-trace",
1528 .data
= &show_unhandled_signals
,
1529 .maxlen
= sizeof(int),
1531 .proc_handler
= proc_dointvec
1534 #if defined(CONFIG_OPTPROBES)
1536 .procname
= "kprobes-optimization",
1537 .data
= &sysctl_kprobes_optimization
,
1538 .maxlen
= sizeof(int),
1540 .proc_handler
= proc_kprobes_optimization_handler
,
1548 static struct ctl_table dev_table
[] = {
1552 static DEFINE_SPINLOCK(sysctl_lock
);
1554 /* called under sysctl_lock */
1555 static int use_table(struct ctl_table_header
*p
)
1557 if (unlikely(p
->unregistering
))
1563 /* called under sysctl_lock */
1564 static void unuse_table(struct ctl_table_header
*p
)
1567 if (unlikely(p
->unregistering
))
1568 complete(p
->unregistering
);
1571 /* called under sysctl_lock, will reacquire if has to wait */
1572 static void start_unregistering(struct ctl_table_header
*p
)
1575 * if p->used is 0, nobody will ever touch that entry again;
1576 * we'll eliminate all paths to it before dropping sysctl_lock
1578 if (unlikely(p
->used
)) {
1579 struct completion wait
;
1580 init_completion(&wait
);
1581 p
->unregistering
= &wait
;
1582 spin_unlock(&sysctl_lock
);
1583 wait_for_completion(&wait
);
1584 spin_lock(&sysctl_lock
);
1586 /* anything non-NULL; we'll never dereference it */
1587 p
->unregistering
= ERR_PTR(-EINVAL
);
1590 * do not remove from the list until nobody holds it; walking the
1591 * list in do_sysctl() relies on that.
1593 list_del_init(&p
->ctl_entry
);
1596 void sysctl_head_get(struct ctl_table_header
*head
)
1598 spin_lock(&sysctl_lock
);
1600 spin_unlock(&sysctl_lock
);
1603 void sysctl_head_put(struct ctl_table_header
*head
)
1605 spin_lock(&sysctl_lock
);
1607 kfree_rcu(head
, rcu
);
1608 spin_unlock(&sysctl_lock
);
1611 struct ctl_table_header
*sysctl_head_grab(struct ctl_table_header
*head
)
1615 spin_lock(&sysctl_lock
);
1616 if (!use_table(head
))
1617 head
= ERR_PTR(-ENOENT
);
1618 spin_unlock(&sysctl_lock
);
1622 void sysctl_head_finish(struct ctl_table_header
*head
)
1626 spin_lock(&sysctl_lock
);
1628 spin_unlock(&sysctl_lock
);
1631 static struct ctl_table_set
*
1632 lookup_header_set(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1634 struct ctl_table_set
*set
= &root
->default_set
;
1636 set
= root
->lookup(root
, namespaces
);
1640 static struct list_head
*
1641 lookup_header_list(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1643 struct ctl_table_set
*set
= lookup_header_set(root
, namespaces
);
1647 struct ctl_table_header
*__sysctl_head_next(struct nsproxy
*namespaces
,
1648 struct ctl_table_header
*prev
)
1650 struct ctl_table_root
*root
;
1651 struct list_head
*header_list
;
1652 struct ctl_table_header
*head
;
1653 struct list_head
*tmp
;
1655 spin_lock(&sysctl_lock
);
1658 tmp
= &prev
->ctl_entry
;
1662 tmp
= &root_table_header
.ctl_entry
;
1664 head
= list_entry(tmp
, struct ctl_table_header
, ctl_entry
);
1666 if (!use_table(head
))
1668 spin_unlock(&sysctl_lock
);
1673 header_list
= lookup_header_list(root
, namespaces
);
1674 if (tmp
!= header_list
)
1678 root
= list_entry(root
->root_list
.next
,
1679 struct ctl_table_root
, root_list
);
1680 if (root
== &sysctl_table_root
)
1682 header_list
= lookup_header_list(root
, namespaces
);
1683 } while (list_empty(header_list
));
1684 tmp
= header_list
->next
;
1687 spin_unlock(&sysctl_lock
);
1691 struct ctl_table_header
*sysctl_head_next(struct ctl_table_header
*prev
)
1693 return __sysctl_head_next(current
->nsproxy
, prev
);
1696 void register_sysctl_root(struct ctl_table_root
*root
)
1698 spin_lock(&sysctl_lock
);
1699 list_add_tail(&root
->root_list
, &sysctl_table_root
.root_list
);
1700 spin_unlock(&sysctl_lock
);
1704 * sysctl_perm does NOT grant the superuser all rights automatically, because
1705 * some sysctl variables are readonly even to root.
1708 static int test_perm(int mode
, int op
)
1710 if (!current_euid())
1712 else if (in_egroup_p(0))
1714 if ((op
& ~mode
& (MAY_READ
|MAY_WRITE
|MAY_EXEC
)) == 0)
1719 int sysctl_perm(struct ctl_table_root
*root
, struct ctl_table
*table
, int op
)
1723 if (root
->permissions
)
1724 mode
= root
->permissions(root
, current
->nsproxy
, table
);
1728 return test_perm(mode
, op
);
1731 static void sysctl_set_parent(struct ctl_table
*parent
, struct ctl_table
*table
)
1733 for (; table
->procname
; table
++) {
1734 table
->parent
= parent
;
1736 sysctl_set_parent(table
, table
->child
);
1740 static __init
int sysctl_init(void)
1742 sysctl_set_parent(NULL
, root_table
);
1743 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1744 sysctl_check_table(current
->nsproxy
, root_table
);
1749 core_initcall(sysctl_init
);
1751 static struct ctl_table
*is_branch_in(struct ctl_table
*branch
,
1752 struct ctl_table
*table
)
1754 struct ctl_table
*p
;
1755 const char *s
= branch
->procname
;
1757 /* branch should have named subdirectory as its first element */
1758 if (!s
|| !branch
->child
)
1761 /* ... and nothing else */
1762 if (branch
[1].procname
)
1765 /* table should contain subdirectory with the same name */
1766 for (p
= table
; p
->procname
; p
++) {
1769 if (p
->procname
&& strcmp(p
->procname
, s
) == 0)
1775 /* see if attaching q to p would be an improvement */
1776 static void try_attach(struct ctl_table_header
*p
, struct ctl_table_header
*q
)
1778 struct ctl_table
*to
= p
->ctl_table
, *by
= q
->ctl_table
;
1779 struct ctl_table
*next
;
1781 int not_in_parent
= !p
->attached_by
;
1783 while ((next
= is_branch_in(by
, to
)) != NULL
) {
1784 if (by
== q
->attached_by
)
1786 if (to
== p
->attached_by
)
1792 if (is_better
&& not_in_parent
) {
1793 q
->attached_by
= by
;
1794 q
->attached_to
= to
;
1800 * __register_sysctl_paths - register a sysctl hierarchy
1801 * @root: List of sysctl headers to register on
1802 * @namespaces: Data to compute which lists of sysctl entries are visible
1803 * @path: The path to the directory the sysctl table is in.
1804 * @table: the top-level table structure
1806 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1807 * array. A completely 0 filled entry terminates the table.
1809 * The members of the &struct ctl_table structure are used as follows:
1811 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1812 * enter a sysctl file
1814 * data - a pointer to data for use by proc_handler
1816 * maxlen - the maximum size in bytes of the data
1818 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1820 * child - a pointer to the child sysctl table if this entry is a directory, or
1823 * proc_handler - the text handler routine (described below)
1825 * de - for internal use by the sysctl routines
1827 * extra1, extra2 - extra pointers usable by the proc handler routines
1829 * Leaf nodes in the sysctl tree will be represented by a single file
1830 * under /proc; non-leaf nodes will be represented by directories.
1832 * sysctl(2) can automatically manage read and write requests through
1833 * the sysctl table. The data and maxlen fields of the ctl_table
1834 * struct enable minimal validation of the values being written to be
1835 * performed, and the mode field allows minimal authentication.
1837 * There must be a proc_handler routine for any terminal nodes
1838 * mirrored under /proc/sys (non-terminals are handled by a built-in
1839 * directory handler). Several default handlers are available to
1840 * cover common cases -
1842 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1843 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1844 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1846 * It is the handler's job to read the input buffer from user memory
1847 * and process it. The handler should return 0 on success.
1849 * This routine returns %NULL on a failure to register, and a pointer
1850 * to the table header on success.
1852 struct ctl_table_header
*__register_sysctl_paths(
1853 struct ctl_table_root
*root
,
1854 struct nsproxy
*namespaces
,
1855 const struct ctl_path
*path
, struct ctl_table
*table
)
1857 struct ctl_table_header
*header
;
1858 struct ctl_table
*new, **prevp
;
1859 unsigned int n
, npath
;
1860 struct ctl_table_set
*set
;
1862 /* Count the path components */
1863 for (npath
= 0; path
[npath
].procname
; ++npath
)
1867 * For each path component, allocate a 2-element ctl_table array.
1868 * The first array element will be filled with the sysctl entry
1869 * for this, the second will be the sentinel (procname == 0).
1871 * We allocate everything in one go so that we don't have to
1872 * worry about freeing additional memory in unregister_sysctl_table.
1874 header
= kzalloc(sizeof(struct ctl_table_header
) +
1875 (2 * npath
* sizeof(struct ctl_table
)), GFP_KERNEL
);
1879 new = (struct ctl_table
*) (header
+ 1);
1881 /* Now connect the dots */
1882 prevp
= &header
->ctl_table
;
1883 for (n
= 0; n
< npath
; ++n
, ++path
) {
1884 /* Copy the procname */
1885 new->procname
= path
->procname
;
1889 prevp
= &new->child
;
1894 header
->ctl_table_arg
= table
;
1896 INIT_LIST_HEAD(&header
->ctl_entry
);
1898 header
->unregistering
= NULL
;
1899 header
->root
= root
;
1900 sysctl_set_parent(NULL
, header
->ctl_table
);
1902 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1903 if (sysctl_check_table(namespaces
, header
->ctl_table
)) {
1908 spin_lock(&sysctl_lock
);
1909 header
->set
= lookup_header_set(root
, namespaces
);
1910 header
->attached_by
= header
->ctl_table
;
1911 header
->attached_to
= root_table
;
1912 header
->parent
= &root_table_header
;
1913 for (set
= header
->set
; set
; set
= set
->parent
) {
1914 struct ctl_table_header
*p
;
1915 list_for_each_entry(p
, &set
->list
, ctl_entry
) {
1916 if (p
->unregistering
)
1918 try_attach(p
, header
);
1921 header
->parent
->count
++;
1922 list_add_tail(&header
->ctl_entry
, &header
->set
->list
);
1923 spin_unlock(&sysctl_lock
);
1929 * register_sysctl_table_path - register a sysctl table hierarchy
1930 * @path: The path to the directory the sysctl table is in.
1931 * @table: the top-level table structure
1933 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1934 * array. A completely 0 filled entry terminates the table.
1936 * See __register_sysctl_paths for more details.
1938 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
1939 struct ctl_table
*table
)
1941 return __register_sysctl_paths(&sysctl_table_root
, current
->nsproxy
,
1946 * register_sysctl_table - register a sysctl table hierarchy
1947 * @table: the top-level table structure
1949 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1950 * array. A completely 0 filled entry terminates the table.
1952 * See register_sysctl_paths for more details.
1954 struct ctl_table_header
*register_sysctl_table(struct ctl_table
*table
)
1956 static const struct ctl_path null_path
[] = { {} };
1958 return register_sysctl_paths(null_path
, table
);
1962 * unregister_sysctl_table - unregister a sysctl table hierarchy
1963 * @header: the header returned from register_sysctl_table
1965 * Unregisters the sysctl table and all children. proc entries may not
1966 * actually be removed until they are no longer used by anyone.
1968 void unregister_sysctl_table(struct ctl_table_header
* header
)
1975 spin_lock(&sysctl_lock
);
1976 start_unregistering(header
);
1977 if (!--header
->parent
->count
) {
1979 kfree_rcu(header
->parent
, rcu
);
1981 if (!--header
->count
)
1982 kfree_rcu(header
, rcu
);
1983 spin_unlock(&sysctl_lock
);
1986 int sysctl_is_seen(struct ctl_table_header
*p
)
1988 struct ctl_table_set
*set
= p
->set
;
1990 spin_lock(&sysctl_lock
);
1991 if (p
->unregistering
)
1993 else if (!set
->is_seen
)
1996 res
= set
->is_seen(set
);
1997 spin_unlock(&sysctl_lock
);
2001 void setup_sysctl_set(struct ctl_table_set
*p
,
2002 struct ctl_table_set
*parent
,
2003 int (*is_seen
)(struct ctl_table_set
*))
2005 INIT_LIST_HEAD(&p
->list
);
2006 p
->parent
= parent
? parent
: &sysctl_table_root
.default_set
;
2007 p
->is_seen
= is_seen
;
2010 #else /* !CONFIG_SYSCTL */
2011 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
2016 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
2017 struct ctl_table
*table
)
2022 void unregister_sysctl_table(struct ctl_table_header
* table
)
2026 void setup_sysctl_set(struct ctl_table_set
*p
,
2027 struct ctl_table_set
*parent
,
2028 int (*is_seen
)(struct ctl_table_set
*))
2032 void sysctl_head_put(struct ctl_table_header
*head
)
2036 #endif /* CONFIG_SYSCTL */
2042 #ifdef CONFIG_PROC_SYSCTL
2044 static int _proc_do_string(void* data
, int maxlen
, int write
,
2045 void __user
*buffer
,
2046 size_t *lenp
, loff_t
*ppos
)
2052 if (!data
|| !maxlen
|| !*lenp
) {
2060 while (len
< *lenp
) {
2061 if (get_user(c
, p
++))
2063 if (c
== 0 || c
== '\n')
2069 if(copy_from_user(data
, buffer
, len
))
2071 ((char *) data
)[len
] = 0;
2089 if(copy_to_user(buffer
, data
, len
))
2092 if(put_user('\n', ((char __user
*) buffer
) + len
))
2103 * proc_dostring - read a string sysctl
2104 * @table: the sysctl table
2105 * @write: %TRUE if this is a write to the sysctl file
2106 * @buffer: the user buffer
2107 * @lenp: the size of the user buffer
2108 * @ppos: file position
2110 * Reads/writes a string from/to the user buffer. If the kernel
2111 * buffer provided is not large enough to hold the string, the
2112 * string is truncated. The copied string is %NULL-terminated.
2113 * If the string is being read by the user process, it is copied
2114 * and a newline '\n' is added. It is truncated if the buffer is
2117 * Returns 0 on success.
2119 int proc_dostring(struct ctl_table
*table
, int write
,
2120 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2122 return _proc_do_string(table
->data
, table
->maxlen
, write
,
2123 buffer
, lenp
, ppos
);
2126 static size_t proc_skip_spaces(char **buf
)
2129 char *tmp
= skip_spaces(*buf
);
2135 static void proc_skip_char(char **buf
, size_t *size
, const char v
)
2145 #define TMPBUFLEN 22
2147 * proc_get_long - reads an ASCII formatted integer from a user buffer
2149 * @buf: a kernel buffer
2150 * @size: size of the kernel buffer
2151 * @val: this is where the number will be stored
2152 * @neg: set to %TRUE if number is negative
2153 * @perm_tr: a vector which contains the allowed trailers
2154 * @perm_tr_len: size of the perm_tr vector
2155 * @tr: pointer to store the trailer character
2157 * In case of success %0 is returned and @buf and @size are updated with
2158 * the amount of bytes read. If @tr is non-NULL and a trailing
2159 * character exists (size is non-zero after returning from this
2160 * function), @tr is updated with the trailing character.
2162 static int proc_get_long(char **buf
, size_t *size
,
2163 unsigned long *val
, bool *neg
,
2164 const char *perm_tr
, unsigned perm_tr_len
, char *tr
)
2167 char *p
, tmp
[TMPBUFLEN
];
2173 if (len
> TMPBUFLEN
- 1)
2174 len
= TMPBUFLEN
- 1;
2176 memcpy(tmp
, *buf
, len
);
2180 if (*p
== '-' && *size
> 1) {
2188 *val
= simple_strtoul(p
, &p
, 0);
2192 /* We don't know if the next char is whitespace thus we may accept
2193 * invalid integers (e.g. 1234...a) or two integers instead of one
2194 * (e.g. 123...1). So lets not allow such large numbers. */
2195 if (len
== TMPBUFLEN
- 1)
2198 if (len
< *size
&& perm_tr_len
&& !memchr(perm_tr
, *p
, perm_tr_len
))
2201 if (tr
&& (len
< *size
))
2211 * proc_put_long - converts an integer to a decimal ASCII formatted string
2213 * @buf: the user buffer
2214 * @size: the size of the user buffer
2215 * @val: the integer to be converted
2216 * @neg: sign of the number, %TRUE for negative
2218 * In case of success %0 is returned and @buf and @size are updated with
2219 * the amount of bytes written.
2221 static int proc_put_long(void __user
**buf
, size_t *size
, unsigned long val
,
2225 char tmp
[TMPBUFLEN
], *p
= tmp
;
2227 sprintf(p
, "%s%lu", neg
? "-" : "", val
);
2231 if (copy_to_user(*buf
, tmp
, len
))
2239 static int proc_put_char(void __user
**buf
, size_t *size
, char c
)
2242 char __user
**buffer
= (char __user
**)buf
;
2243 if (put_user(c
, *buffer
))
2245 (*size
)--, (*buffer
)++;
2251 static int do_proc_dointvec_conv(bool *negp
, unsigned long *lvalp
,
2253 int write
, void *data
)
2256 *valp
= *negp
? -*lvalp
: *lvalp
;
2261 *lvalp
= (unsigned long)-val
;
2264 *lvalp
= (unsigned long)val
;
2270 static const char proc_wspace_sep
[] = { ' ', '\t', '\n' };
2272 static int __do_proc_dointvec(void *tbl_data
, struct ctl_table
*table
,
2273 int write
, void __user
*buffer
,
2274 size_t *lenp
, loff_t
*ppos
,
2275 int (*conv
)(bool *negp
, unsigned long *lvalp
, int *valp
,
2276 int write
, void *data
),
2279 int *i
, vleft
, first
= 1, err
= 0;
2280 unsigned long page
= 0;
2284 if (!tbl_data
|| !table
->maxlen
|| !*lenp
|| (*ppos
&& !write
)) {
2289 i
= (int *) tbl_data
;
2290 vleft
= table
->maxlen
/ sizeof(*i
);
2294 conv
= do_proc_dointvec_conv
;
2297 if (left
> PAGE_SIZE
- 1)
2298 left
= PAGE_SIZE
- 1;
2299 page
= __get_free_page(GFP_TEMPORARY
);
2300 kbuf
= (char *) page
;
2303 if (copy_from_user(kbuf
, buffer
, left
)) {
2310 for (; left
&& vleft
--; i
++, first
=0) {
2315 left
-= proc_skip_spaces(&kbuf
);
2319 err
= proc_get_long(&kbuf
, &left
, &lval
, &neg
,
2321 sizeof(proc_wspace_sep
), NULL
);
2324 if (conv(&neg
, &lval
, i
, 1, data
)) {
2329 if (conv(&neg
, &lval
, i
, 0, data
)) {
2334 err
= proc_put_char(&buffer
, &left
, '\t');
2337 err
= proc_put_long(&buffer
, &left
, lval
, neg
);
2343 if (!write
&& !first
&& left
&& !err
)
2344 err
= proc_put_char(&buffer
, &left
, '\n');
2345 if (write
&& !err
&& left
)
2346 left
-= proc_skip_spaces(&kbuf
);
2351 return err
? : -EINVAL
;
2358 static int do_proc_dointvec(struct ctl_table
*table
, int write
,
2359 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
,
2360 int (*conv
)(bool *negp
, unsigned long *lvalp
, int *valp
,
2361 int write
, void *data
),
2364 return __do_proc_dointvec(table
->data
, table
, write
,
2365 buffer
, lenp
, ppos
, conv
, data
);
2369 * proc_dointvec - read a vector of integers
2370 * @table: the sysctl table
2371 * @write: %TRUE if this is a write to the sysctl file
2372 * @buffer: the user buffer
2373 * @lenp: the size of the user buffer
2374 * @ppos: file position
2376 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2377 * values from/to the user buffer, treated as an ASCII string.
2379 * Returns 0 on success.
2381 int proc_dointvec(struct ctl_table
*table
, int write
,
2382 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2384 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2389 * Taint values can only be increased
2390 * This means we can safely use a temporary.
2392 static int proc_taint(struct ctl_table
*table
, int write
,
2393 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2396 unsigned long tmptaint
= get_taint();
2399 if (write
&& !capable(CAP_SYS_ADMIN
))
2404 err
= proc_doulongvec_minmax(&t
, write
, buffer
, lenp
, ppos
);
2410 * Poor man's atomic or. Not worth adding a primitive
2411 * to everyone's atomic.h for this
2414 for (i
= 0; i
< BITS_PER_LONG
&& tmptaint
>> i
; i
++) {
2415 if ((tmptaint
>> i
) & 1)
2423 #ifdef CONFIG_PRINTK
2424 static int proc_dmesg_restrict(struct ctl_table
*table
, int write
,
2425 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2427 if (write
&& !capable(CAP_SYS_ADMIN
))
2430 return proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
2434 struct do_proc_dointvec_minmax_conv_param
{
2439 static int do_proc_dointvec_minmax_conv(bool *negp
, unsigned long *lvalp
,
2441 int write
, void *data
)
2443 struct do_proc_dointvec_minmax_conv_param
*param
= data
;
2445 int val
= *negp
? -*lvalp
: *lvalp
;
2446 if ((param
->min
&& *param
->min
> val
) ||
2447 (param
->max
&& *param
->max
< val
))
2454 *lvalp
= (unsigned long)-val
;
2457 *lvalp
= (unsigned long)val
;
2464 * proc_dointvec_minmax - read a vector of integers with min/max values
2465 * @table: the sysctl table
2466 * @write: %TRUE if this is a write to the sysctl file
2467 * @buffer: the user buffer
2468 * @lenp: the size of the user buffer
2469 * @ppos: file position
2471 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2472 * values from/to the user buffer, treated as an ASCII string.
2474 * This routine will ensure the values are within the range specified by
2475 * table->extra1 (min) and table->extra2 (max).
2477 * Returns 0 on success.
2479 int proc_dointvec_minmax(struct ctl_table
*table
, int write
,
2480 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2482 struct do_proc_dointvec_minmax_conv_param param
= {
2483 .min
= (int *) table
->extra1
,
2484 .max
= (int *) table
->extra2
,
2486 return do_proc_dointvec(table
, write
, buffer
, lenp
, ppos
,
2487 do_proc_dointvec_minmax_conv
, ¶m
);
2490 static int __do_proc_doulongvec_minmax(void *data
, struct ctl_table
*table
, int write
,
2491 void __user
*buffer
,
2492 size_t *lenp
, loff_t
*ppos
,
2493 unsigned long convmul
,
2494 unsigned long convdiv
)
2496 unsigned long *i
, *min
, *max
;
2497 int vleft
, first
= 1, err
= 0;
2498 unsigned long page
= 0;
2502 if (!data
|| !table
->maxlen
|| !*lenp
|| (*ppos
&& !write
)) {
2507 i
= (unsigned long *) data
;
2508 min
= (unsigned long *) table
->extra1
;
2509 max
= (unsigned long *) table
->extra2
;
2510 vleft
= table
->maxlen
/ sizeof(unsigned long);
2514 if (left
> PAGE_SIZE
- 1)
2515 left
= PAGE_SIZE
- 1;
2516 page
= __get_free_page(GFP_TEMPORARY
);
2517 kbuf
= (char *) page
;
2520 if (copy_from_user(kbuf
, buffer
, left
)) {
2527 for (; left
&& vleft
--; i
++, first
= 0) {
2533 left
-= proc_skip_spaces(&kbuf
);
2535 err
= proc_get_long(&kbuf
, &left
, &val
, &neg
,
2537 sizeof(proc_wspace_sep
), NULL
);
2542 if ((min
&& val
< *min
) || (max
&& val
> *max
))
2546 val
= convdiv
* (*i
) / convmul
;
2548 err
= proc_put_char(&buffer
, &left
, '\t');
2549 err
= proc_put_long(&buffer
, &left
, val
, false);
2555 if (!write
&& !first
&& left
&& !err
)
2556 err
= proc_put_char(&buffer
, &left
, '\n');
2558 left
-= proc_skip_spaces(&kbuf
);
2563 return err
? : -EINVAL
;
2570 static int do_proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2571 void __user
*buffer
,
2572 size_t *lenp
, loff_t
*ppos
,
2573 unsigned long convmul
,
2574 unsigned long convdiv
)
2576 return __do_proc_doulongvec_minmax(table
->data
, table
, write
,
2577 buffer
, lenp
, ppos
, convmul
, convdiv
);
2581 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2582 * @table: the sysctl table
2583 * @write: %TRUE if this is a write to the sysctl file
2584 * @buffer: the user buffer
2585 * @lenp: the size of the user buffer
2586 * @ppos: file position
2588 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2589 * values from/to the user buffer, treated as an ASCII string.
2591 * This routine will ensure the values are within the range specified by
2592 * table->extra1 (min) and table->extra2 (max).
2594 * Returns 0 on success.
2596 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2597 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2599 return do_proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
, 1l, 1l);
2603 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2604 * @table: the sysctl table
2605 * @write: %TRUE if this is a write to the sysctl file
2606 * @buffer: the user buffer
2607 * @lenp: the size of the user buffer
2608 * @ppos: file position
2610 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2611 * values from/to the user buffer, treated as an ASCII string. The values
2612 * are treated as milliseconds, and converted to jiffies when they are stored.
2614 * This routine will ensure the values are within the range specified by
2615 * table->extra1 (min) and table->extra2 (max).
2617 * Returns 0 on success.
2619 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2620 void __user
*buffer
,
2621 size_t *lenp
, loff_t
*ppos
)
2623 return do_proc_doulongvec_minmax(table
, write
, buffer
,
2624 lenp
, ppos
, HZ
, 1000l);
2628 static int do_proc_dointvec_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2630 int write
, void *data
)
2633 if (*lvalp
> LONG_MAX
/ HZ
)
2635 *valp
= *negp
? -(*lvalp
*HZ
) : (*lvalp
*HZ
);
2641 lval
= (unsigned long)-val
;
2644 lval
= (unsigned long)val
;
2651 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2653 int write
, void *data
)
2656 if (USER_HZ
< HZ
&& *lvalp
> (LONG_MAX
/ HZ
) * USER_HZ
)
2658 *valp
= clock_t_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2664 lval
= (unsigned long)-val
;
2667 lval
= (unsigned long)val
;
2669 *lvalp
= jiffies_to_clock_t(lval
);
2674 static int do_proc_dointvec_ms_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2676 int write
, void *data
)
2679 *valp
= msecs_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2685 lval
= (unsigned long)-val
;
2688 lval
= (unsigned long)val
;
2690 *lvalp
= jiffies_to_msecs(lval
);
2696 * proc_dointvec_jiffies - read a vector of integers as seconds
2697 * @table: the sysctl table
2698 * @write: %TRUE if this is a write to the sysctl file
2699 * @buffer: the user buffer
2700 * @lenp: the size of the user buffer
2701 * @ppos: file position
2703 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2704 * values from/to the user buffer, treated as an ASCII string.
2705 * The values read are assumed to be in seconds, and are converted into
2708 * Returns 0 on success.
2710 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
,
2711 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2713 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2714 do_proc_dointvec_jiffies_conv
,NULL
);
2718 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2719 * @table: the sysctl table
2720 * @write: %TRUE if this is a write to the sysctl file
2721 * @buffer: the user buffer
2722 * @lenp: the size of the user buffer
2723 * @ppos: pointer to the file position
2725 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2726 * values from/to the user buffer, treated as an ASCII string.
2727 * The values read are assumed to be in 1/USER_HZ seconds, and
2728 * are converted into jiffies.
2730 * Returns 0 on success.
2732 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
,
2733 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2735 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2736 do_proc_dointvec_userhz_jiffies_conv
,NULL
);
2740 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2741 * @table: the sysctl table
2742 * @write: %TRUE if this is a write to the sysctl file
2743 * @buffer: the user buffer
2744 * @lenp: the size of the user buffer
2745 * @ppos: file position
2746 * @ppos: the current position in the file
2748 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2749 * values from/to the user buffer, treated as an ASCII string.
2750 * The values read are assumed to be in 1/1000 seconds, and
2751 * are converted into jiffies.
2753 * Returns 0 on success.
2755 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
,
2756 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2758 return do_proc_dointvec(table
, write
, buffer
, lenp
, ppos
,
2759 do_proc_dointvec_ms_jiffies_conv
, NULL
);
2762 static int proc_do_cad_pid(struct ctl_table
*table
, int write
,
2763 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2765 struct pid
*new_pid
;
2769 tmp
= pid_vnr(cad_pid
);
2771 r
= __do_proc_dointvec(&tmp
, table
, write
, buffer
,
2772 lenp
, ppos
, NULL
, NULL
);
2776 new_pid
= find_get_pid(tmp
);
2780 put_pid(xchg(&cad_pid
, new_pid
));
2785 * proc_do_large_bitmap - read/write from/to a large bitmap
2786 * @table: the sysctl table
2787 * @write: %TRUE if this is a write to the sysctl file
2788 * @buffer: the user buffer
2789 * @lenp: the size of the user buffer
2790 * @ppos: file position
2792 * The bitmap is stored at table->data and the bitmap length (in bits)
2795 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2796 * large bitmaps may be represented in a compact manner. Writing into
2797 * the file will clear the bitmap then update it with the given input.
2799 * Returns 0 on success.
2801 int proc_do_large_bitmap(struct ctl_table
*table
, int write
,
2802 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2806 size_t left
= *lenp
;
2807 unsigned long bitmap_len
= table
->maxlen
;
2808 unsigned long *bitmap
= (unsigned long *) table
->data
;
2809 unsigned long *tmp_bitmap
= NULL
;
2810 char tr_a
[] = { '-', ',', '\n' }, tr_b
[] = { ',', '\n', 0 }, c
;
2812 if (!bitmap_len
|| !left
|| (*ppos
&& !write
)) {
2818 unsigned long page
= 0;
2821 if (left
> PAGE_SIZE
- 1)
2822 left
= PAGE_SIZE
- 1;
2824 page
= __get_free_page(GFP_TEMPORARY
);
2825 kbuf
= (char *) page
;
2828 if (copy_from_user(kbuf
, buffer
, left
)) {
2834 tmp_bitmap
= kzalloc(BITS_TO_LONGS(bitmap_len
) * sizeof(unsigned long),
2840 proc_skip_char(&kbuf
, &left
, '\n');
2841 while (!err
&& left
) {
2842 unsigned long val_a
, val_b
;
2845 err
= proc_get_long(&kbuf
, &left
, &val_a
, &neg
, tr_a
,
2849 if (val_a
>= bitmap_len
|| neg
) {
2861 err
= proc_get_long(&kbuf
, &left
, &val_b
,
2862 &neg
, tr_b
, sizeof(tr_b
),
2866 if (val_b
>= bitmap_len
|| neg
||
2877 while (val_a
<= val_b
)
2878 set_bit(val_a
++, tmp_bitmap
);
2881 proc_skip_char(&kbuf
, &left
, '\n');
2885 unsigned long bit_a
, bit_b
= 0;
2888 bit_a
= find_next_bit(bitmap
, bitmap_len
, bit_b
);
2889 if (bit_a
>= bitmap_len
)
2891 bit_b
= find_next_zero_bit(bitmap
, bitmap_len
,
2895 err
= proc_put_char(&buffer
, &left
, ',');
2899 err
= proc_put_long(&buffer
, &left
, bit_a
, false);
2902 if (bit_a
!= bit_b
) {
2903 err
= proc_put_char(&buffer
, &left
, '-');
2906 err
= proc_put_long(&buffer
, &left
, bit_b
, false);
2914 err
= proc_put_char(&buffer
, &left
, '\n');
2920 bitmap_or(bitmap
, bitmap
, tmp_bitmap
, bitmap_len
);
2922 memcpy(bitmap
, tmp_bitmap
,
2923 BITS_TO_LONGS(bitmap_len
) * sizeof(unsigned long));
2935 #else /* CONFIG_PROC_SYSCTL */
2937 int proc_dostring(struct ctl_table
*table
, int write
,
2938 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2943 int proc_dointvec(struct ctl_table
*table
, int write
,
2944 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2949 int proc_dointvec_minmax(struct ctl_table
*table
, int write
,
2950 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2955 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
,
2956 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2961 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
,
2962 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2967 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
,
2968 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2973 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2974 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2979 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2980 void __user
*buffer
,
2981 size_t *lenp
, loff_t
*ppos
)
2987 #endif /* CONFIG_PROC_SYSCTL */
2990 * No sense putting this after each symbol definition, twice,
2991 * exception granted :-)
2993 EXPORT_SYMBOL(proc_dointvec
);
2994 EXPORT_SYMBOL(proc_dointvec_jiffies
);
2995 EXPORT_SYMBOL(proc_dointvec_minmax
);
2996 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies
);
2997 EXPORT_SYMBOL(proc_dointvec_ms_jiffies
);
2998 EXPORT_SYMBOL(proc_dostring
);
2999 EXPORT_SYMBOL(proc_doulongvec_minmax
);
3000 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax
);
3001 EXPORT_SYMBOL(register_sysctl_table
);
3002 EXPORT_SYMBOL(register_sysctl_paths
);
3003 EXPORT_SYMBOL(unregister_sysctl_table
);