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/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/ctype.h>
30 #include <linux/kmemcheck.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/ratelimit.h>
40 #include <linux/compaction.h>
41 #include <linux/hugetlb.h>
42 #include <linux/initrd.h>
43 #include <linux/key.h>
44 #include <linux/times.h>
45 #include <linux/limits.h>
46 #include <linux/dcache.h>
47 #include <linux/syscalls.h>
48 #include <linux/vmstat.h>
49 #include <linux/nfs_fs.h>
50 #include <linux/acpi.h>
51 #include <linux/reboot.h>
52 #include <linux/ftrace.h>
53 #include <linux/perf_event.h>
54 #include <linux/kprobes.h>
55 #include <linux/pipe_fs_i.h>
57 #include <asm/uaccess.h>
58 #include <asm/processor.h>
62 #include <asm/stacktrace.h>
65 #ifdef CONFIG_BSD_PROCESS_ACCT
66 #include <linux/acct.h>
68 #ifdef CONFIG_RT_MUTEXES
69 #include <linux/rtmutex.h>
71 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
72 #include <linux/lockdep.h>
74 #ifdef CONFIG_CHR_DEV_SG
78 #ifdef CONFIG_LOCKUP_DETECTOR
79 #include <linux/nmi.h>
83 #if defined(CONFIG_SYSCTL)
85 /* External variables not in a header file. */
86 extern int sysctl_overcommit_memory
;
87 extern int sysctl_overcommit_ratio
;
88 extern int sysctl_panic_on_oom
;
89 extern int sysctl_oom_kill_allocating_task
;
90 extern int sysctl_oom_dump_tasks
;
91 extern int max_threads
;
92 extern int core_uses_pid
;
93 extern int suid_dumpable
;
94 extern char core_pattern
[];
95 extern unsigned int core_pipe_limit
;
97 extern int min_free_kbytes
;
98 extern int pid_max_min
, pid_max_max
;
99 extern int sysctl_drop_caches
;
100 extern int percpu_pagelist_fraction
;
101 extern int compat_log
;
102 extern int latencytop_enabled
;
103 extern int sysctl_nr_open_min
, sysctl_nr_open_max
;
105 extern int sysctl_nr_trim_pages
;
108 extern int blk_iopoll_enabled
;
111 /* Constants used for minimum and maximum */
112 #ifdef CONFIG_LOCKUP_DETECTOR
113 static int sixty
= 60;
114 static int neg_one
= -1;
118 static int __maybe_unused one
= 1;
119 static int __maybe_unused two
= 2;
120 static unsigned long one_ul
= 1;
121 static int one_hundred
= 100;
123 static int ten_thousand
= 10000;
126 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
127 static unsigned long dirty_bytes_min
= 2 * PAGE_SIZE
;
129 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
130 static int maxolduid
= 65535;
131 static int minolduid
;
132 static int min_percpu_pagelist_fract
= 8;
134 static int ngroups_max
= NGROUPS_MAX
;
137 #include <asm/system.h>
140 #ifdef CONFIG_SPARC64
141 extern int sysctl_tsb_ratio
;
145 extern int pwrsw_enabled
;
146 extern int unaligned_enabled
;
150 #ifdef CONFIG_MATHEMU
151 extern int sysctl_ieee_emulation_warnings
;
153 extern int sysctl_userprocess_debug
;
154 extern int spin_retry
;
158 extern int no_unaligned_warning
;
159 extern int unaligned_dump_stack
;
162 extern struct ratelimit_state printk_ratelimit_state
;
164 #ifdef CONFIG_PROC_SYSCTL
165 static int proc_do_cad_pid(struct ctl_table
*table
, int write
,
166 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
167 static int proc_taint(struct ctl_table
*table
, int write
,
168 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
171 #ifdef CONFIG_MAGIC_SYSRQ
172 static int __sysrq_enabled
; /* Note: sysrq code ises it's own private copy */
174 static int sysrq_sysctl_handler(ctl_table
*table
, int write
,
175 void __user
*buffer
, size_t *lenp
,
180 error
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
185 sysrq_toggle_support(__sysrq_enabled
);
192 static struct ctl_table root_table
[];
193 static struct ctl_table_root sysctl_table_root
;
194 static struct ctl_table_header root_table_header
= {
196 .ctl_table
= root_table
,
197 .ctl_entry
= LIST_HEAD_INIT(sysctl_table_root
.default_set
.list
),
198 .root
= &sysctl_table_root
,
199 .set
= &sysctl_table_root
.default_set
,
201 static struct ctl_table_root sysctl_table_root
= {
202 .root_list
= LIST_HEAD_INIT(sysctl_table_root
.root_list
),
203 .default_set
.list
= LIST_HEAD_INIT(root_table_header
.ctl_entry
),
206 static struct ctl_table kern_table
[];
207 static struct ctl_table vm_table
[];
208 static struct ctl_table fs_table
[];
209 static struct ctl_table debug_table
[];
210 static struct ctl_table dev_table
[];
211 extern struct ctl_table random_table
[];
212 #ifdef CONFIG_INOTIFY_USER
213 extern struct ctl_table inotify_table
[];
216 extern struct ctl_table epoll_table
[];
219 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
220 int sysctl_legacy_va_layout
;
223 /* The default sysctl tables: */
225 static struct ctl_table root_table
[] = {
227 .procname
= "kernel",
244 .child
= debug_table
,
252 * NOTE: do not add new entries to this table unless you have read
253 * Documentation/sysctl/ctl_unnumbered.txt
258 #ifdef CONFIG_SCHED_DEBUG
259 static int min_sched_granularity_ns
= 100000; /* 100 usecs */
260 static int max_sched_granularity_ns
= NSEC_PER_SEC
; /* 1 second */
261 static int min_wakeup_granularity_ns
; /* 0 usecs */
262 static int max_wakeup_granularity_ns
= NSEC_PER_SEC
; /* 1 second */
263 static int min_sched_tunable_scaling
= SCHED_TUNABLESCALING_NONE
;
264 static int max_sched_tunable_scaling
= SCHED_TUNABLESCALING_END
-1;
265 static int min_sched_shares_ratelimit
= 100000; /* 100 usec */
266 static int max_sched_shares_ratelimit
= NSEC_PER_SEC
; /* 1 second */
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_shares_ratelimit",
312 .data
= &sysctl_sched_shares_ratelimit
,
313 .maxlen
= sizeof(unsigned int),
315 .proc_handler
= sched_proc_update_handler
,
316 .extra1
= &min_sched_shares_ratelimit
,
317 .extra2
= &max_sched_shares_ratelimit
,
320 .procname
= "sched_tunable_scaling",
321 .data
= &sysctl_sched_tunable_scaling
,
322 .maxlen
= sizeof(enum sched_tunable_scaling
),
324 .proc_handler
= sched_proc_update_handler
,
325 .extra1
= &min_sched_tunable_scaling
,
326 .extra2
= &max_sched_tunable_scaling
,
329 .procname
= "sched_shares_thresh",
330 .data
= &sysctl_sched_shares_thresh
,
331 .maxlen
= sizeof(unsigned int),
333 .proc_handler
= proc_dointvec_minmax
,
337 .procname
= "sched_migration_cost",
338 .data
= &sysctl_sched_migration_cost
,
339 .maxlen
= sizeof(unsigned int),
341 .proc_handler
= proc_dointvec
,
344 .procname
= "sched_nr_migrate",
345 .data
= &sysctl_sched_nr_migrate
,
346 .maxlen
= sizeof(unsigned int),
348 .proc_handler
= proc_dointvec
,
351 .procname
= "sched_time_avg",
352 .data
= &sysctl_sched_time_avg
,
353 .maxlen
= sizeof(unsigned int),
355 .proc_handler
= proc_dointvec
,
358 .procname
= "timer_migration",
359 .data
= &sysctl_timer_migration
,
360 .maxlen
= sizeof(unsigned int),
362 .proc_handler
= proc_dointvec_minmax
,
368 .procname
= "sched_rt_period_us",
369 .data
= &sysctl_sched_rt_period
,
370 .maxlen
= sizeof(unsigned int),
372 .proc_handler
= sched_rt_handler
,
375 .procname
= "sched_rt_runtime_us",
376 .data
= &sysctl_sched_rt_runtime
,
377 .maxlen
= sizeof(int),
379 .proc_handler
= sched_rt_handler
,
382 .procname
= "sched_compat_yield",
383 .data
= &sysctl_sched_compat_yield
,
384 .maxlen
= sizeof(unsigned int),
386 .proc_handler
= proc_dointvec
,
388 #ifdef CONFIG_PROVE_LOCKING
390 .procname
= "prove_locking",
391 .data
= &prove_locking
,
392 .maxlen
= sizeof(int),
394 .proc_handler
= proc_dointvec
,
397 #ifdef CONFIG_LOCK_STAT
399 .procname
= "lock_stat",
401 .maxlen
= sizeof(int),
403 .proc_handler
= proc_dointvec
,
408 .data
= &panic_timeout
,
409 .maxlen
= sizeof(int),
411 .proc_handler
= proc_dointvec
,
414 .procname
= "core_uses_pid",
415 .data
= &core_uses_pid
,
416 .maxlen
= sizeof(int),
418 .proc_handler
= proc_dointvec
,
421 .procname
= "core_pattern",
422 .data
= core_pattern
,
423 .maxlen
= CORENAME_MAX_SIZE
,
425 .proc_handler
= proc_dostring
,
428 .procname
= "core_pipe_limit",
429 .data
= &core_pipe_limit
,
430 .maxlen
= sizeof(unsigned int),
432 .proc_handler
= proc_dointvec
,
434 #ifdef CONFIG_PROC_SYSCTL
436 .procname
= "tainted",
437 .maxlen
= sizeof(long),
439 .proc_handler
= proc_taint
,
442 #ifdef CONFIG_LATENCYTOP
444 .procname
= "latencytop",
445 .data
= &latencytop_enabled
,
446 .maxlen
= sizeof(int),
448 .proc_handler
= proc_dointvec
,
451 #ifdef CONFIG_BLK_DEV_INITRD
453 .procname
= "real-root-dev",
454 .data
= &real_root_dev
,
455 .maxlen
= sizeof(int),
457 .proc_handler
= proc_dointvec
,
461 .procname
= "print-fatal-signals",
462 .data
= &print_fatal_signals
,
463 .maxlen
= sizeof(int),
465 .proc_handler
= proc_dointvec
,
469 .procname
= "reboot-cmd",
470 .data
= reboot_command
,
473 .proc_handler
= proc_dostring
,
476 .procname
= "stop-a",
477 .data
= &stop_a_enabled
,
478 .maxlen
= sizeof (int),
480 .proc_handler
= proc_dointvec
,
483 .procname
= "scons-poweroff",
484 .data
= &scons_pwroff
,
485 .maxlen
= sizeof (int),
487 .proc_handler
= proc_dointvec
,
490 #ifdef CONFIG_SPARC64
492 .procname
= "tsb-ratio",
493 .data
= &sysctl_tsb_ratio
,
494 .maxlen
= sizeof (int),
496 .proc_handler
= proc_dointvec
,
501 .procname
= "soft-power",
502 .data
= &pwrsw_enabled
,
503 .maxlen
= sizeof (int),
505 .proc_handler
= proc_dointvec
,
508 .procname
= "unaligned-trap",
509 .data
= &unaligned_enabled
,
510 .maxlen
= sizeof (int),
512 .proc_handler
= proc_dointvec
,
516 .procname
= "ctrl-alt-del",
518 .maxlen
= sizeof(int),
520 .proc_handler
= proc_dointvec
,
522 #ifdef CONFIG_FUNCTION_TRACER
524 .procname
= "ftrace_enabled",
525 .data
= &ftrace_enabled
,
526 .maxlen
= sizeof(int),
528 .proc_handler
= ftrace_enable_sysctl
,
531 #ifdef CONFIG_STACK_TRACER
533 .procname
= "stack_tracer_enabled",
534 .data
= &stack_tracer_enabled
,
535 .maxlen
= sizeof(int),
537 .proc_handler
= stack_trace_sysctl
,
540 #ifdef CONFIG_TRACING
542 .procname
= "ftrace_dump_on_oops",
543 .data
= &ftrace_dump_on_oops
,
544 .maxlen
= sizeof(int),
546 .proc_handler
= proc_dointvec
,
549 #ifdef CONFIG_MODULES
551 .procname
= "modprobe",
552 .data
= &modprobe_path
,
553 .maxlen
= KMOD_PATH_LEN
,
555 .proc_handler
= proc_dostring
,
558 .procname
= "modules_disabled",
559 .data
= &modules_disabled
,
560 .maxlen
= sizeof(int),
562 /* only handle a transition from default "0" to "1" */
563 .proc_handler
= proc_dointvec_minmax
,
568 #ifdef CONFIG_HOTPLUG
570 .procname
= "hotplug",
571 .data
= &uevent_helper
,
572 .maxlen
= UEVENT_HELPER_PATH_LEN
,
574 .proc_handler
= proc_dostring
,
577 #ifdef CONFIG_CHR_DEV_SG
579 .procname
= "sg-big-buff",
580 .data
= &sg_big_buff
,
581 .maxlen
= sizeof (int),
583 .proc_handler
= proc_dointvec
,
586 #ifdef CONFIG_BSD_PROCESS_ACCT
590 .maxlen
= 3*sizeof(int),
592 .proc_handler
= proc_dointvec
,
595 #ifdef CONFIG_MAGIC_SYSRQ
598 .data
= &__sysrq_enabled
,
599 .maxlen
= sizeof (int),
601 .proc_handler
= sysrq_sysctl_handler
,
604 #ifdef CONFIG_PROC_SYSCTL
606 .procname
= "cad_pid",
608 .maxlen
= sizeof (int),
610 .proc_handler
= proc_do_cad_pid
,
614 .procname
= "threads-max",
615 .data
= &max_threads
,
616 .maxlen
= sizeof(int),
618 .proc_handler
= proc_dointvec
,
621 .procname
= "random",
623 .child
= random_table
,
626 .procname
= "overflowuid",
627 .data
= &overflowuid
,
628 .maxlen
= sizeof(int),
630 .proc_handler
= proc_dointvec_minmax
,
631 .extra1
= &minolduid
,
632 .extra2
= &maxolduid
,
635 .procname
= "overflowgid",
636 .data
= &overflowgid
,
637 .maxlen
= sizeof(int),
639 .proc_handler
= proc_dointvec_minmax
,
640 .extra1
= &minolduid
,
641 .extra2
= &maxolduid
,
644 #ifdef CONFIG_MATHEMU
646 .procname
= "ieee_emulation_warnings",
647 .data
= &sysctl_ieee_emulation_warnings
,
648 .maxlen
= sizeof(int),
650 .proc_handler
= proc_dointvec
,
654 .procname
= "userprocess_debug",
655 .data
= &show_unhandled_signals
,
656 .maxlen
= sizeof(int),
658 .proc_handler
= proc_dointvec
,
662 .procname
= "pid_max",
664 .maxlen
= sizeof (int),
666 .proc_handler
= proc_dointvec_minmax
,
667 .extra1
= &pid_max_min
,
668 .extra2
= &pid_max_max
,
671 .procname
= "panic_on_oops",
672 .data
= &panic_on_oops
,
673 .maxlen
= sizeof(int),
675 .proc_handler
= proc_dointvec
,
677 #if defined CONFIG_PRINTK
679 .procname
= "printk",
680 .data
= &console_loglevel
,
681 .maxlen
= 4*sizeof(int),
683 .proc_handler
= proc_dointvec
,
686 .procname
= "printk_ratelimit",
687 .data
= &printk_ratelimit_state
.interval
,
688 .maxlen
= sizeof(int),
690 .proc_handler
= proc_dointvec_jiffies
,
693 .procname
= "printk_ratelimit_burst",
694 .data
= &printk_ratelimit_state
.burst
,
695 .maxlen
= sizeof(int),
697 .proc_handler
= proc_dointvec
,
700 .procname
= "printk_delay",
701 .data
= &printk_delay_msec
,
702 .maxlen
= sizeof(int),
704 .proc_handler
= proc_dointvec_minmax
,
706 .extra2
= &ten_thousand
,
710 .procname
= "ngroups_max",
711 .data
= &ngroups_max
,
712 .maxlen
= sizeof (int),
714 .proc_handler
= proc_dointvec
,
716 #if defined(CONFIG_LOCKUP_DETECTOR)
718 .procname
= "watchdog",
719 .data
= &watchdog_enabled
,
720 .maxlen
= sizeof (int),
722 .proc_handler
= proc_dowatchdog_enabled
,
725 .procname
= "watchdog_thresh",
726 .data
= &softlockup_thresh
,
727 .maxlen
= sizeof(int),
729 .proc_handler
= proc_dowatchdog_thresh
,
734 .procname
= "softlockup_panic",
735 .data
= &softlockup_panic
,
736 .maxlen
= sizeof(int),
738 .proc_handler
= proc_dointvec_minmax
,
743 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) && !defined(CONFIG_LOCKUP_DETECTOR)
745 .procname
= "unknown_nmi_panic",
746 .data
= &unknown_nmi_panic
,
747 .maxlen
= sizeof (int),
749 .proc_handler
= proc_dointvec
,
752 .procname
= "nmi_watchdog",
753 .data
= &nmi_watchdog_enabled
,
754 .maxlen
= sizeof (int),
756 .proc_handler
= proc_nmi_enabled
,
759 #if defined(CONFIG_X86)
761 .procname
= "panic_on_unrecovered_nmi",
762 .data
= &panic_on_unrecovered_nmi
,
763 .maxlen
= sizeof(int),
765 .proc_handler
= proc_dointvec
,
768 .procname
= "panic_on_io_nmi",
769 .data
= &panic_on_io_nmi
,
770 .maxlen
= sizeof(int),
772 .proc_handler
= proc_dointvec
,
775 .procname
= "bootloader_type",
776 .data
= &bootloader_type
,
777 .maxlen
= sizeof (int),
779 .proc_handler
= proc_dointvec
,
782 .procname
= "bootloader_version",
783 .data
= &bootloader_version
,
784 .maxlen
= sizeof (int),
786 .proc_handler
= proc_dointvec
,
789 .procname
= "kstack_depth_to_print",
790 .data
= &kstack_depth_to_print
,
791 .maxlen
= sizeof(int),
793 .proc_handler
= proc_dointvec
,
796 .procname
= "io_delay_type",
797 .data
= &io_delay_type
,
798 .maxlen
= sizeof(int),
800 .proc_handler
= proc_dointvec
,
803 #if defined(CONFIG_MMU)
805 .procname
= "randomize_va_space",
806 .data
= &randomize_va_space
,
807 .maxlen
= sizeof(int),
809 .proc_handler
= proc_dointvec
,
812 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
814 .procname
= "spin_retry",
816 .maxlen
= sizeof (int),
818 .proc_handler
= proc_dointvec
,
821 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
823 .procname
= "acpi_video_flags",
824 .data
= &acpi_realmode_flags
,
825 .maxlen
= sizeof (unsigned long),
827 .proc_handler
= proc_doulongvec_minmax
,
832 .procname
= "ignore-unaligned-usertrap",
833 .data
= &no_unaligned_warning
,
834 .maxlen
= sizeof (int),
836 .proc_handler
= proc_dointvec
,
839 .procname
= "unaligned-dump-stack",
840 .data
= &unaligned_dump_stack
,
841 .maxlen
= sizeof (int),
843 .proc_handler
= proc_dointvec
,
846 #ifdef CONFIG_DETECT_HUNG_TASK
848 .procname
= "hung_task_panic",
849 .data
= &sysctl_hung_task_panic
,
850 .maxlen
= sizeof(int),
852 .proc_handler
= proc_dointvec_minmax
,
857 .procname
= "hung_task_check_count",
858 .data
= &sysctl_hung_task_check_count
,
859 .maxlen
= sizeof(unsigned long),
861 .proc_handler
= proc_doulongvec_minmax
,
864 .procname
= "hung_task_timeout_secs",
865 .data
= &sysctl_hung_task_timeout_secs
,
866 .maxlen
= sizeof(unsigned long),
868 .proc_handler
= proc_dohung_task_timeout_secs
,
871 .procname
= "hung_task_warnings",
872 .data
= &sysctl_hung_task_warnings
,
873 .maxlen
= sizeof(unsigned long),
875 .proc_handler
= proc_doulongvec_minmax
,
880 .procname
= "compat-log",
882 .maxlen
= sizeof (int),
884 .proc_handler
= proc_dointvec
,
887 #ifdef CONFIG_RT_MUTEXES
889 .procname
= "max_lock_depth",
890 .data
= &max_lock_depth
,
891 .maxlen
= sizeof(int),
893 .proc_handler
= proc_dointvec
,
897 .procname
= "poweroff_cmd",
898 .data
= &poweroff_cmd
,
899 .maxlen
= POWEROFF_CMD_PATH_LEN
,
901 .proc_handler
= proc_dostring
,
907 .child
= key_sysctls
,
910 #ifdef CONFIG_RCU_TORTURE_TEST
912 .procname
= "rcutorture_runnable",
913 .data
= &rcutorture_runnable
,
914 .maxlen
= sizeof(int),
916 .proc_handler
= proc_dointvec
,
919 #ifdef CONFIG_PERF_EVENTS
921 .procname
= "perf_event_paranoid",
922 .data
= &sysctl_perf_event_paranoid
,
923 .maxlen
= sizeof(sysctl_perf_event_paranoid
),
925 .proc_handler
= proc_dointvec
,
928 .procname
= "perf_event_mlock_kb",
929 .data
= &sysctl_perf_event_mlock
,
930 .maxlen
= sizeof(sysctl_perf_event_mlock
),
932 .proc_handler
= proc_dointvec
,
935 .procname
= "perf_event_max_sample_rate",
936 .data
= &sysctl_perf_event_sample_rate
,
937 .maxlen
= sizeof(sysctl_perf_event_sample_rate
),
939 .proc_handler
= proc_dointvec
,
942 #ifdef CONFIG_KMEMCHECK
944 .procname
= "kmemcheck",
945 .data
= &kmemcheck_enabled
,
946 .maxlen
= sizeof(int),
948 .proc_handler
= proc_dointvec
,
953 .procname
= "blk_iopoll",
954 .data
= &blk_iopoll_enabled
,
955 .maxlen
= sizeof(int),
957 .proc_handler
= proc_dointvec
,
961 * NOTE: do not add new entries to this table unless you have read
962 * Documentation/sysctl/ctl_unnumbered.txt
967 static struct ctl_table vm_table
[] = {
969 .procname
= "overcommit_memory",
970 .data
= &sysctl_overcommit_memory
,
971 .maxlen
= sizeof(sysctl_overcommit_memory
),
973 .proc_handler
= proc_dointvec
,
976 .procname
= "panic_on_oom",
977 .data
= &sysctl_panic_on_oom
,
978 .maxlen
= sizeof(sysctl_panic_on_oom
),
980 .proc_handler
= proc_dointvec
,
983 .procname
= "oom_kill_allocating_task",
984 .data
= &sysctl_oom_kill_allocating_task
,
985 .maxlen
= sizeof(sysctl_oom_kill_allocating_task
),
987 .proc_handler
= proc_dointvec
,
990 .procname
= "oom_dump_tasks",
991 .data
= &sysctl_oom_dump_tasks
,
992 .maxlen
= sizeof(sysctl_oom_dump_tasks
),
994 .proc_handler
= proc_dointvec
,
997 .procname
= "overcommit_ratio",
998 .data
= &sysctl_overcommit_ratio
,
999 .maxlen
= sizeof(sysctl_overcommit_ratio
),
1001 .proc_handler
= proc_dointvec
,
1004 .procname
= "page-cluster",
1005 .data
= &page_cluster
,
1006 .maxlen
= sizeof(int),
1008 .proc_handler
= proc_dointvec
,
1011 .procname
= "dirty_background_ratio",
1012 .data
= &dirty_background_ratio
,
1013 .maxlen
= sizeof(dirty_background_ratio
),
1015 .proc_handler
= dirty_background_ratio_handler
,
1017 .extra2
= &one_hundred
,
1020 .procname
= "dirty_background_bytes",
1021 .data
= &dirty_background_bytes
,
1022 .maxlen
= sizeof(dirty_background_bytes
),
1024 .proc_handler
= dirty_background_bytes_handler
,
1028 .procname
= "dirty_ratio",
1029 .data
= &vm_dirty_ratio
,
1030 .maxlen
= sizeof(vm_dirty_ratio
),
1032 .proc_handler
= dirty_ratio_handler
,
1034 .extra2
= &one_hundred
,
1037 .procname
= "dirty_bytes",
1038 .data
= &vm_dirty_bytes
,
1039 .maxlen
= sizeof(vm_dirty_bytes
),
1041 .proc_handler
= dirty_bytes_handler
,
1042 .extra1
= &dirty_bytes_min
,
1045 .procname
= "dirty_writeback_centisecs",
1046 .data
= &dirty_writeback_interval
,
1047 .maxlen
= sizeof(dirty_writeback_interval
),
1049 .proc_handler
= dirty_writeback_centisecs_handler
,
1052 .procname
= "dirty_expire_centisecs",
1053 .data
= &dirty_expire_interval
,
1054 .maxlen
= sizeof(dirty_expire_interval
),
1056 .proc_handler
= proc_dointvec
,
1059 .procname
= "nr_pdflush_threads",
1060 .data
= &nr_pdflush_threads
,
1061 .maxlen
= sizeof nr_pdflush_threads
,
1062 .mode
= 0444 /* read-only*/,
1063 .proc_handler
= proc_dointvec
,
1066 .procname
= "swappiness",
1067 .data
= &vm_swappiness
,
1068 .maxlen
= sizeof(vm_swappiness
),
1070 .proc_handler
= proc_dointvec_minmax
,
1072 .extra2
= &one_hundred
,
1074 #ifdef CONFIG_HUGETLB_PAGE
1076 .procname
= "nr_hugepages",
1078 .maxlen
= sizeof(unsigned long),
1080 .proc_handler
= hugetlb_sysctl_handler
,
1081 .extra1
= (void *)&hugetlb_zero
,
1082 .extra2
= (void *)&hugetlb_infinity
,
1086 .procname
= "nr_hugepages_mempolicy",
1088 .maxlen
= sizeof(unsigned long),
1090 .proc_handler
= &hugetlb_mempolicy_sysctl_handler
,
1091 .extra1
= (void *)&hugetlb_zero
,
1092 .extra2
= (void *)&hugetlb_infinity
,
1096 .procname
= "hugetlb_shm_group",
1097 .data
= &sysctl_hugetlb_shm_group
,
1098 .maxlen
= sizeof(gid_t
),
1100 .proc_handler
= proc_dointvec
,
1103 .procname
= "hugepages_treat_as_movable",
1104 .data
= &hugepages_treat_as_movable
,
1105 .maxlen
= sizeof(int),
1107 .proc_handler
= hugetlb_treat_movable_handler
,
1110 .procname
= "nr_overcommit_hugepages",
1112 .maxlen
= sizeof(unsigned long),
1114 .proc_handler
= hugetlb_overcommit_handler
,
1115 .extra1
= (void *)&hugetlb_zero
,
1116 .extra2
= (void *)&hugetlb_infinity
,
1120 .procname
= "lowmem_reserve_ratio",
1121 .data
= &sysctl_lowmem_reserve_ratio
,
1122 .maxlen
= sizeof(sysctl_lowmem_reserve_ratio
),
1124 .proc_handler
= lowmem_reserve_ratio_sysctl_handler
,
1127 .procname
= "drop_caches",
1128 .data
= &sysctl_drop_caches
,
1129 .maxlen
= sizeof(int),
1131 .proc_handler
= drop_caches_sysctl_handler
,
1133 #ifdef CONFIG_COMPACTION
1135 .procname
= "compact_memory",
1136 .data
= &sysctl_compact_memory
,
1137 .maxlen
= sizeof(int),
1139 .proc_handler
= sysctl_compaction_handler
,
1142 .procname
= "extfrag_threshold",
1143 .data
= &sysctl_extfrag_threshold
,
1144 .maxlen
= sizeof(int),
1146 .proc_handler
= sysctl_extfrag_handler
,
1147 .extra1
= &min_extfrag_threshold
,
1148 .extra2
= &max_extfrag_threshold
,
1151 #endif /* CONFIG_COMPACTION */
1153 .procname
= "min_free_kbytes",
1154 .data
= &min_free_kbytes
,
1155 .maxlen
= sizeof(min_free_kbytes
),
1157 .proc_handler
= min_free_kbytes_sysctl_handler
,
1161 .procname
= "percpu_pagelist_fraction",
1162 .data
= &percpu_pagelist_fraction
,
1163 .maxlen
= sizeof(percpu_pagelist_fraction
),
1165 .proc_handler
= percpu_pagelist_fraction_sysctl_handler
,
1166 .extra1
= &min_percpu_pagelist_fract
,
1170 .procname
= "max_map_count",
1171 .data
= &sysctl_max_map_count
,
1172 .maxlen
= sizeof(sysctl_max_map_count
),
1174 .proc_handler
= proc_dointvec_minmax
,
1179 .procname
= "nr_trim_pages",
1180 .data
= &sysctl_nr_trim_pages
,
1181 .maxlen
= sizeof(sysctl_nr_trim_pages
),
1183 .proc_handler
= proc_dointvec_minmax
,
1188 .procname
= "laptop_mode",
1189 .data
= &laptop_mode
,
1190 .maxlen
= sizeof(laptop_mode
),
1192 .proc_handler
= proc_dointvec_jiffies
,
1195 .procname
= "block_dump",
1196 .data
= &block_dump
,
1197 .maxlen
= sizeof(block_dump
),
1199 .proc_handler
= proc_dointvec
,
1203 .procname
= "vfs_cache_pressure",
1204 .data
= &sysctl_vfs_cache_pressure
,
1205 .maxlen
= sizeof(sysctl_vfs_cache_pressure
),
1207 .proc_handler
= proc_dointvec
,
1210 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1212 .procname
= "legacy_va_layout",
1213 .data
= &sysctl_legacy_va_layout
,
1214 .maxlen
= sizeof(sysctl_legacy_va_layout
),
1216 .proc_handler
= proc_dointvec
,
1222 .procname
= "zone_reclaim_mode",
1223 .data
= &zone_reclaim_mode
,
1224 .maxlen
= sizeof(zone_reclaim_mode
),
1226 .proc_handler
= proc_dointvec
,
1230 .procname
= "min_unmapped_ratio",
1231 .data
= &sysctl_min_unmapped_ratio
,
1232 .maxlen
= sizeof(sysctl_min_unmapped_ratio
),
1234 .proc_handler
= sysctl_min_unmapped_ratio_sysctl_handler
,
1236 .extra2
= &one_hundred
,
1239 .procname
= "min_slab_ratio",
1240 .data
= &sysctl_min_slab_ratio
,
1241 .maxlen
= sizeof(sysctl_min_slab_ratio
),
1243 .proc_handler
= sysctl_min_slab_ratio_sysctl_handler
,
1245 .extra2
= &one_hundred
,
1250 .procname
= "stat_interval",
1251 .data
= &sysctl_stat_interval
,
1252 .maxlen
= sizeof(sysctl_stat_interval
),
1254 .proc_handler
= proc_dointvec_jiffies
,
1259 .procname
= "mmap_min_addr",
1260 .data
= &dac_mmap_min_addr
,
1261 .maxlen
= sizeof(unsigned long),
1263 .proc_handler
= mmap_min_addr_handler
,
1268 .procname
= "numa_zonelist_order",
1269 .data
= &numa_zonelist_order
,
1270 .maxlen
= NUMA_ZONELIST_ORDER_LEN
,
1272 .proc_handler
= numa_zonelist_order_handler
,
1275 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1276 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1278 .procname
= "vdso_enabled",
1279 .data
= &vdso_enabled
,
1280 .maxlen
= sizeof(vdso_enabled
),
1282 .proc_handler
= proc_dointvec
,
1286 #ifdef CONFIG_HIGHMEM
1288 .procname
= "highmem_is_dirtyable",
1289 .data
= &vm_highmem_is_dirtyable
,
1290 .maxlen
= sizeof(vm_highmem_is_dirtyable
),
1292 .proc_handler
= proc_dointvec_minmax
,
1298 .procname
= "scan_unevictable_pages",
1299 .data
= &scan_unevictable_pages
,
1300 .maxlen
= sizeof(scan_unevictable_pages
),
1302 .proc_handler
= scan_unevictable_handler
,
1304 #ifdef CONFIG_MEMORY_FAILURE
1306 .procname
= "memory_failure_early_kill",
1307 .data
= &sysctl_memory_failure_early_kill
,
1308 .maxlen
= sizeof(sysctl_memory_failure_early_kill
),
1310 .proc_handler
= proc_dointvec_minmax
,
1315 .procname
= "memory_failure_recovery",
1316 .data
= &sysctl_memory_failure_recovery
,
1317 .maxlen
= sizeof(sysctl_memory_failure_recovery
),
1319 .proc_handler
= proc_dointvec_minmax
,
1326 * NOTE: do not add new entries to this table unless you have read
1327 * Documentation/sysctl/ctl_unnumbered.txt
1332 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1333 static struct ctl_table binfmt_misc_table
[] = {
1338 static struct ctl_table fs_table
[] = {
1340 .procname
= "inode-nr",
1341 .data
= &inodes_stat
,
1342 .maxlen
= 2*sizeof(int),
1344 .proc_handler
= proc_dointvec
,
1347 .procname
= "inode-state",
1348 .data
= &inodes_stat
,
1349 .maxlen
= 7*sizeof(int),
1351 .proc_handler
= proc_dointvec
,
1354 .procname
= "file-nr",
1355 .data
= &files_stat
,
1356 .maxlen
= 3*sizeof(int),
1358 .proc_handler
= proc_nr_files
,
1361 .procname
= "file-max",
1362 .data
= &files_stat
.max_files
,
1363 .maxlen
= sizeof(int),
1365 .proc_handler
= proc_dointvec
,
1368 .procname
= "nr_open",
1369 .data
= &sysctl_nr_open
,
1370 .maxlen
= sizeof(int),
1372 .proc_handler
= proc_dointvec_minmax
,
1373 .extra1
= &sysctl_nr_open_min
,
1374 .extra2
= &sysctl_nr_open_max
,
1377 .procname
= "dentry-state",
1378 .data
= &dentry_stat
,
1379 .maxlen
= 6*sizeof(int),
1381 .proc_handler
= proc_dointvec
,
1384 .procname
= "overflowuid",
1385 .data
= &fs_overflowuid
,
1386 .maxlen
= sizeof(int),
1388 .proc_handler
= proc_dointvec_minmax
,
1389 .extra1
= &minolduid
,
1390 .extra2
= &maxolduid
,
1393 .procname
= "overflowgid",
1394 .data
= &fs_overflowgid
,
1395 .maxlen
= sizeof(int),
1397 .proc_handler
= proc_dointvec_minmax
,
1398 .extra1
= &minolduid
,
1399 .extra2
= &maxolduid
,
1401 #ifdef CONFIG_FILE_LOCKING
1403 .procname
= "leases-enable",
1404 .data
= &leases_enable
,
1405 .maxlen
= sizeof(int),
1407 .proc_handler
= proc_dointvec
,
1410 #ifdef CONFIG_DNOTIFY
1412 .procname
= "dir-notify-enable",
1413 .data
= &dir_notify_enable
,
1414 .maxlen
= sizeof(int),
1416 .proc_handler
= proc_dointvec
,
1420 #ifdef CONFIG_FILE_LOCKING
1422 .procname
= "lease-break-time",
1423 .data
= &lease_break_time
,
1424 .maxlen
= sizeof(int),
1426 .proc_handler
= proc_dointvec
,
1431 .procname
= "aio-nr",
1433 .maxlen
= sizeof(aio_nr
),
1435 .proc_handler
= proc_doulongvec_minmax
,
1438 .procname
= "aio-max-nr",
1439 .data
= &aio_max_nr
,
1440 .maxlen
= sizeof(aio_max_nr
),
1442 .proc_handler
= proc_doulongvec_minmax
,
1444 #endif /* CONFIG_AIO */
1445 #ifdef CONFIG_INOTIFY_USER
1447 .procname
= "inotify",
1449 .child
= inotify_table
,
1454 .procname
= "epoll",
1456 .child
= epoll_table
,
1461 .procname
= "suid_dumpable",
1462 .data
= &suid_dumpable
,
1463 .maxlen
= sizeof(int),
1465 .proc_handler
= proc_dointvec_minmax
,
1469 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1471 .procname
= "binfmt_misc",
1473 .child
= binfmt_misc_table
,
1477 .procname
= "pipe-max-size",
1478 .data
= &pipe_max_size
,
1479 .maxlen
= sizeof(int),
1481 .proc_handler
= &pipe_proc_fn
,
1482 .extra1
= &pipe_min_size
,
1485 * NOTE: do not add new entries to this table unless you have read
1486 * Documentation/sysctl/ctl_unnumbered.txt
1491 static struct ctl_table debug_table
[] = {
1492 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1493 defined(CONFIG_S390)
1495 .procname
= "exception-trace",
1496 .data
= &show_unhandled_signals
,
1497 .maxlen
= sizeof(int),
1499 .proc_handler
= proc_dointvec
1502 #if defined(CONFIG_OPTPROBES)
1504 .procname
= "kprobes-optimization",
1505 .data
= &sysctl_kprobes_optimization
,
1506 .maxlen
= sizeof(int),
1508 .proc_handler
= proc_kprobes_optimization_handler
,
1516 static struct ctl_table dev_table
[] = {
1520 static DEFINE_SPINLOCK(sysctl_lock
);
1522 /* called under sysctl_lock */
1523 static int use_table(struct ctl_table_header
*p
)
1525 if (unlikely(p
->unregistering
))
1531 /* called under sysctl_lock */
1532 static void unuse_table(struct ctl_table_header
*p
)
1535 if (unlikely(p
->unregistering
))
1536 complete(p
->unregistering
);
1539 /* called under sysctl_lock, will reacquire if has to wait */
1540 static void start_unregistering(struct ctl_table_header
*p
)
1543 * if p->used is 0, nobody will ever touch that entry again;
1544 * we'll eliminate all paths to it before dropping sysctl_lock
1546 if (unlikely(p
->used
)) {
1547 struct completion wait
;
1548 init_completion(&wait
);
1549 p
->unregistering
= &wait
;
1550 spin_unlock(&sysctl_lock
);
1551 wait_for_completion(&wait
);
1552 spin_lock(&sysctl_lock
);
1554 /* anything non-NULL; we'll never dereference it */
1555 p
->unregistering
= ERR_PTR(-EINVAL
);
1558 * do not remove from the list until nobody holds it; walking the
1559 * list in do_sysctl() relies on that.
1561 list_del_init(&p
->ctl_entry
);
1564 void sysctl_head_get(struct ctl_table_header
*head
)
1566 spin_lock(&sysctl_lock
);
1568 spin_unlock(&sysctl_lock
);
1571 void sysctl_head_put(struct ctl_table_header
*head
)
1573 spin_lock(&sysctl_lock
);
1576 spin_unlock(&sysctl_lock
);
1579 struct ctl_table_header
*sysctl_head_grab(struct ctl_table_header
*head
)
1583 spin_lock(&sysctl_lock
);
1584 if (!use_table(head
))
1585 head
= ERR_PTR(-ENOENT
);
1586 spin_unlock(&sysctl_lock
);
1590 void sysctl_head_finish(struct ctl_table_header
*head
)
1594 spin_lock(&sysctl_lock
);
1596 spin_unlock(&sysctl_lock
);
1599 static struct ctl_table_set
*
1600 lookup_header_set(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1602 struct ctl_table_set
*set
= &root
->default_set
;
1604 set
= root
->lookup(root
, namespaces
);
1608 static struct list_head
*
1609 lookup_header_list(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1611 struct ctl_table_set
*set
= lookup_header_set(root
, namespaces
);
1615 struct ctl_table_header
*__sysctl_head_next(struct nsproxy
*namespaces
,
1616 struct ctl_table_header
*prev
)
1618 struct ctl_table_root
*root
;
1619 struct list_head
*header_list
;
1620 struct ctl_table_header
*head
;
1621 struct list_head
*tmp
;
1623 spin_lock(&sysctl_lock
);
1626 tmp
= &prev
->ctl_entry
;
1630 tmp
= &root_table_header
.ctl_entry
;
1632 head
= list_entry(tmp
, struct ctl_table_header
, ctl_entry
);
1634 if (!use_table(head
))
1636 spin_unlock(&sysctl_lock
);
1641 header_list
= lookup_header_list(root
, namespaces
);
1642 if (tmp
!= header_list
)
1646 root
= list_entry(root
->root_list
.next
,
1647 struct ctl_table_root
, root_list
);
1648 if (root
== &sysctl_table_root
)
1650 header_list
= lookup_header_list(root
, namespaces
);
1651 } while (list_empty(header_list
));
1652 tmp
= header_list
->next
;
1655 spin_unlock(&sysctl_lock
);
1659 struct ctl_table_header
*sysctl_head_next(struct ctl_table_header
*prev
)
1661 return __sysctl_head_next(current
->nsproxy
, prev
);
1664 void register_sysctl_root(struct ctl_table_root
*root
)
1666 spin_lock(&sysctl_lock
);
1667 list_add_tail(&root
->root_list
, &sysctl_table_root
.root_list
);
1668 spin_unlock(&sysctl_lock
);
1672 * sysctl_perm does NOT grant the superuser all rights automatically, because
1673 * some sysctl variables are readonly even to root.
1676 static int test_perm(int mode
, int op
)
1678 if (!current_euid())
1680 else if (in_egroup_p(0))
1682 if ((op
& ~mode
& (MAY_READ
|MAY_WRITE
|MAY_EXEC
)) == 0)
1687 int sysctl_perm(struct ctl_table_root
*root
, struct ctl_table
*table
, int op
)
1692 error
= security_sysctl(table
, op
& (MAY_READ
| MAY_WRITE
| MAY_EXEC
));
1696 if (root
->permissions
)
1697 mode
= root
->permissions(root
, current
->nsproxy
, table
);
1701 return test_perm(mode
, op
);
1704 static void sysctl_set_parent(struct ctl_table
*parent
, struct ctl_table
*table
)
1706 for (; table
->procname
; table
++) {
1707 table
->parent
= parent
;
1709 sysctl_set_parent(table
, table
->child
);
1713 static __init
int sysctl_init(void)
1715 sysctl_set_parent(NULL
, root_table
);
1716 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1719 err
= sysctl_check_table(current
->nsproxy
, root_table
);
1725 core_initcall(sysctl_init
);
1727 static struct ctl_table
*is_branch_in(struct ctl_table
*branch
,
1728 struct ctl_table
*table
)
1730 struct ctl_table
*p
;
1731 const char *s
= branch
->procname
;
1733 /* branch should have named subdirectory as its first element */
1734 if (!s
|| !branch
->child
)
1737 /* ... and nothing else */
1738 if (branch
[1].procname
)
1741 /* table should contain subdirectory with the same name */
1742 for (p
= table
; p
->procname
; p
++) {
1745 if (p
->procname
&& strcmp(p
->procname
, s
) == 0)
1751 /* see if attaching q to p would be an improvement */
1752 static void try_attach(struct ctl_table_header
*p
, struct ctl_table_header
*q
)
1754 struct ctl_table
*to
= p
->ctl_table
, *by
= q
->ctl_table
;
1755 struct ctl_table
*next
;
1757 int not_in_parent
= !p
->attached_by
;
1759 while ((next
= is_branch_in(by
, to
)) != NULL
) {
1760 if (by
== q
->attached_by
)
1762 if (to
== p
->attached_by
)
1768 if (is_better
&& not_in_parent
) {
1769 q
->attached_by
= by
;
1770 q
->attached_to
= to
;
1776 * __register_sysctl_paths - register a sysctl hierarchy
1777 * @root: List of sysctl headers to register on
1778 * @namespaces: Data to compute which lists of sysctl entries are visible
1779 * @path: The path to the directory the sysctl table is in.
1780 * @table: the top-level table structure
1782 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1783 * array. A completely 0 filled entry terminates the table.
1785 * The members of the &struct ctl_table structure are used as follows:
1787 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1788 * enter a sysctl file
1790 * data - a pointer to data for use by proc_handler
1792 * maxlen - the maximum size in bytes of the data
1794 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1796 * child - a pointer to the child sysctl table if this entry is a directory, or
1799 * proc_handler - the text handler routine (described below)
1801 * de - for internal use by the sysctl routines
1803 * extra1, extra2 - extra pointers usable by the proc handler routines
1805 * Leaf nodes in the sysctl tree will be represented by a single file
1806 * under /proc; non-leaf nodes will be represented by directories.
1808 * sysctl(2) can automatically manage read and write requests through
1809 * the sysctl table. The data and maxlen fields of the ctl_table
1810 * struct enable minimal validation of the values being written to be
1811 * performed, and the mode field allows minimal authentication.
1813 * There must be a proc_handler routine for any terminal nodes
1814 * mirrored under /proc/sys (non-terminals are handled by a built-in
1815 * directory handler). Several default handlers are available to
1816 * cover common cases -
1818 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1819 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1820 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1822 * It is the handler's job to read the input buffer from user memory
1823 * and process it. The handler should return 0 on success.
1825 * This routine returns %NULL on a failure to register, and a pointer
1826 * to the table header on success.
1828 struct ctl_table_header
*__register_sysctl_paths(
1829 struct ctl_table_root
*root
,
1830 struct nsproxy
*namespaces
,
1831 const struct ctl_path
*path
, struct ctl_table
*table
)
1833 struct ctl_table_header
*header
;
1834 struct ctl_table
*new, **prevp
;
1835 unsigned int n
, npath
;
1836 struct ctl_table_set
*set
;
1838 /* Count the path components */
1839 for (npath
= 0; path
[npath
].procname
; ++npath
)
1843 * For each path component, allocate a 2-element ctl_table array.
1844 * The first array element will be filled with the sysctl entry
1845 * for this, the second will be the sentinel (procname == 0).
1847 * We allocate everything in one go so that we don't have to
1848 * worry about freeing additional memory in unregister_sysctl_table.
1850 header
= kzalloc(sizeof(struct ctl_table_header
) +
1851 (2 * npath
* sizeof(struct ctl_table
)), GFP_KERNEL
);
1855 new = (struct ctl_table
*) (header
+ 1);
1857 /* Now connect the dots */
1858 prevp
= &header
->ctl_table
;
1859 for (n
= 0; n
< npath
; ++n
, ++path
) {
1860 /* Copy the procname */
1861 new->procname
= path
->procname
;
1865 prevp
= &new->child
;
1870 header
->ctl_table_arg
= table
;
1872 INIT_LIST_HEAD(&header
->ctl_entry
);
1874 header
->unregistering
= NULL
;
1875 header
->root
= root
;
1876 sysctl_set_parent(NULL
, header
->ctl_table
);
1878 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1879 if (sysctl_check_table(namespaces
, header
->ctl_table
)) {
1884 spin_lock(&sysctl_lock
);
1885 header
->set
= lookup_header_set(root
, namespaces
);
1886 header
->attached_by
= header
->ctl_table
;
1887 header
->attached_to
= root_table
;
1888 header
->parent
= &root_table_header
;
1889 for (set
= header
->set
; set
; set
= set
->parent
) {
1890 struct ctl_table_header
*p
;
1891 list_for_each_entry(p
, &set
->list
, ctl_entry
) {
1892 if (p
->unregistering
)
1894 try_attach(p
, header
);
1897 header
->parent
->count
++;
1898 list_add_tail(&header
->ctl_entry
, &header
->set
->list
);
1899 spin_unlock(&sysctl_lock
);
1905 * register_sysctl_table_path - register a sysctl table hierarchy
1906 * @path: The path to the directory the sysctl table is in.
1907 * @table: the top-level table structure
1909 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1910 * array. A completely 0 filled entry terminates the table.
1912 * See __register_sysctl_paths for more details.
1914 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
1915 struct ctl_table
*table
)
1917 return __register_sysctl_paths(&sysctl_table_root
, current
->nsproxy
,
1922 * register_sysctl_table - register a sysctl table hierarchy
1923 * @table: the top-level table structure
1925 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1926 * array. A completely 0 filled entry terminates the table.
1928 * See register_sysctl_paths for more details.
1930 struct ctl_table_header
*register_sysctl_table(struct ctl_table
*table
)
1932 static const struct ctl_path null_path
[] = { {} };
1934 return register_sysctl_paths(null_path
, table
);
1938 * unregister_sysctl_table - unregister a sysctl table hierarchy
1939 * @header: the header returned from register_sysctl_table
1941 * Unregisters the sysctl table and all children. proc entries may not
1942 * actually be removed until they are no longer used by anyone.
1944 void unregister_sysctl_table(struct ctl_table_header
* header
)
1951 spin_lock(&sysctl_lock
);
1952 start_unregistering(header
);
1953 if (!--header
->parent
->count
) {
1955 kfree(header
->parent
);
1957 if (!--header
->count
)
1959 spin_unlock(&sysctl_lock
);
1962 int sysctl_is_seen(struct ctl_table_header
*p
)
1964 struct ctl_table_set
*set
= p
->set
;
1966 spin_lock(&sysctl_lock
);
1967 if (p
->unregistering
)
1969 else if (!set
->is_seen
)
1972 res
= set
->is_seen(set
);
1973 spin_unlock(&sysctl_lock
);
1977 void setup_sysctl_set(struct ctl_table_set
*p
,
1978 struct ctl_table_set
*parent
,
1979 int (*is_seen
)(struct ctl_table_set
*))
1981 INIT_LIST_HEAD(&p
->list
);
1982 p
->parent
= parent
? parent
: &sysctl_table_root
.default_set
;
1983 p
->is_seen
= is_seen
;
1986 #else /* !CONFIG_SYSCTL */
1987 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
1992 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
1993 struct ctl_table
*table
)
1998 void unregister_sysctl_table(struct ctl_table_header
* table
)
2002 void setup_sysctl_set(struct ctl_table_set
*p
,
2003 struct ctl_table_set
*parent
,
2004 int (*is_seen
)(struct ctl_table_set
*))
2008 void sysctl_head_put(struct ctl_table_header
*head
)
2012 #endif /* CONFIG_SYSCTL */
2018 #ifdef CONFIG_PROC_SYSCTL
2020 static int _proc_do_string(void* data
, int maxlen
, int write
,
2021 void __user
*buffer
,
2022 size_t *lenp
, loff_t
*ppos
)
2028 if (!data
|| !maxlen
|| !*lenp
) {
2036 while (len
< *lenp
) {
2037 if (get_user(c
, p
++))
2039 if (c
== 0 || c
== '\n')
2045 if(copy_from_user(data
, buffer
, len
))
2047 ((char *) data
)[len
] = 0;
2065 if(copy_to_user(buffer
, data
, len
))
2068 if(put_user('\n', ((char __user
*) buffer
) + len
))
2079 * proc_dostring - read a string sysctl
2080 * @table: the sysctl table
2081 * @write: %TRUE if this is a write to the sysctl file
2082 * @buffer: the user buffer
2083 * @lenp: the size of the user buffer
2084 * @ppos: file position
2086 * Reads/writes a string from/to the user buffer. If the kernel
2087 * buffer provided is not large enough to hold the string, the
2088 * string is truncated. The copied string is %NULL-terminated.
2089 * If the string is being read by the user process, it is copied
2090 * and a newline '\n' is added. It is truncated if the buffer is
2093 * Returns 0 on success.
2095 int proc_dostring(struct ctl_table
*table
, int write
,
2096 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2098 return _proc_do_string(table
->data
, table
->maxlen
, write
,
2099 buffer
, lenp
, ppos
);
2102 static size_t proc_skip_spaces(char **buf
)
2105 char *tmp
= skip_spaces(*buf
);
2111 static void proc_skip_char(char **buf
, size_t *size
, const char v
)
2121 #define TMPBUFLEN 22
2123 * proc_get_long - reads an ASCII formatted integer from a user buffer
2125 * @buf: a kernel buffer
2126 * @size: size of the kernel buffer
2127 * @val: this is where the number will be stored
2128 * @neg: set to %TRUE if number is negative
2129 * @perm_tr: a vector which contains the allowed trailers
2130 * @perm_tr_len: size of the perm_tr vector
2131 * @tr: pointer to store the trailer character
2133 * In case of success %0 is returned and @buf and @size are updated with
2134 * the amount of bytes read. If @tr is non-NULL and a trailing
2135 * character exists (size is non-zero after returning from this
2136 * function), @tr is updated with the trailing character.
2138 static int proc_get_long(char **buf
, size_t *size
,
2139 unsigned long *val
, bool *neg
,
2140 const char *perm_tr
, unsigned perm_tr_len
, char *tr
)
2143 char *p
, tmp
[TMPBUFLEN
];
2149 if (len
> TMPBUFLEN
- 1)
2150 len
= TMPBUFLEN
- 1;
2152 memcpy(tmp
, *buf
, len
);
2156 if (*p
== '-' && *size
> 1) {
2164 *val
= simple_strtoul(p
, &p
, 0);
2168 /* We don't know if the next char is whitespace thus we may accept
2169 * invalid integers (e.g. 1234...a) or two integers instead of one
2170 * (e.g. 123...1). So lets not allow such large numbers. */
2171 if (len
== TMPBUFLEN
- 1)
2174 if (len
< *size
&& perm_tr_len
&& !memchr(perm_tr
, *p
, perm_tr_len
))
2177 if (tr
&& (len
< *size
))
2187 * proc_put_long - converts an integer to a decimal ASCII formatted string
2189 * @buf: the user buffer
2190 * @size: the size of the user buffer
2191 * @val: the integer to be converted
2192 * @neg: sign of the number, %TRUE for negative
2194 * In case of success %0 is returned and @buf and @size are updated with
2195 * the amount of bytes written.
2197 static int proc_put_long(void __user
**buf
, size_t *size
, unsigned long val
,
2201 char tmp
[TMPBUFLEN
], *p
= tmp
;
2203 sprintf(p
, "%s%lu", neg
? "-" : "", val
);
2207 if (copy_to_user(*buf
, tmp
, len
))
2215 static int proc_put_char(void __user
**buf
, size_t *size
, char c
)
2218 char __user
**buffer
= (char __user
**)buf
;
2219 if (put_user(c
, *buffer
))
2221 (*size
)--, (*buffer
)++;
2227 static int do_proc_dointvec_conv(bool *negp
, unsigned long *lvalp
,
2229 int write
, void *data
)
2232 *valp
= *negp
? -*lvalp
: *lvalp
;
2237 *lvalp
= (unsigned long)-val
;
2240 *lvalp
= (unsigned long)val
;
2246 static const char proc_wspace_sep
[] = { ' ', '\t', '\n' };
2248 static int __do_proc_dointvec(void *tbl_data
, struct ctl_table
*table
,
2249 int write
, void __user
*buffer
,
2250 size_t *lenp
, loff_t
*ppos
,
2251 int (*conv
)(bool *negp
, unsigned long *lvalp
, int *valp
,
2252 int write
, void *data
),
2255 int *i
, vleft
, first
= 1, err
= 0;
2256 unsigned long page
= 0;
2260 if (!tbl_data
|| !table
->maxlen
|| !*lenp
|| (*ppos
&& !write
)) {
2265 i
= (int *) tbl_data
;
2266 vleft
= table
->maxlen
/ sizeof(*i
);
2270 conv
= do_proc_dointvec_conv
;
2273 if (left
> PAGE_SIZE
- 1)
2274 left
= PAGE_SIZE
- 1;
2275 page
= __get_free_page(GFP_TEMPORARY
);
2276 kbuf
= (char *) page
;
2279 if (copy_from_user(kbuf
, buffer
, left
)) {
2286 for (; left
&& vleft
--; i
++, first
=0) {
2291 left
-= proc_skip_spaces(&kbuf
);
2295 err
= proc_get_long(&kbuf
, &left
, &lval
, &neg
,
2297 sizeof(proc_wspace_sep
), NULL
);
2300 if (conv(&neg
, &lval
, i
, 1, data
)) {
2305 if (conv(&neg
, &lval
, i
, 0, data
)) {
2310 err
= proc_put_char(&buffer
, &left
, '\t');
2313 err
= proc_put_long(&buffer
, &left
, lval
, neg
);
2319 if (!write
&& !first
&& left
&& !err
)
2320 err
= proc_put_char(&buffer
, &left
, '\n');
2321 if (write
&& !err
&& left
)
2322 left
-= proc_skip_spaces(&kbuf
);
2327 return err
? : -EINVAL
;
2334 static int do_proc_dointvec(struct ctl_table
*table
, int write
,
2335 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
,
2336 int (*conv
)(bool *negp
, unsigned long *lvalp
, int *valp
,
2337 int write
, void *data
),
2340 return __do_proc_dointvec(table
->data
, table
, write
,
2341 buffer
, lenp
, ppos
, conv
, data
);
2345 * proc_dointvec - read a vector of integers
2346 * @table: the sysctl table
2347 * @write: %TRUE if this is a write to the sysctl file
2348 * @buffer: the user buffer
2349 * @lenp: the size of the user buffer
2350 * @ppos: file position
2352 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2353 * values from/to the user buffer, treated as an ASCII string.
2355 * Returns 0 on success.
2357 int proc_dointvec(struct ctl_table
*table
, int write
,
2358 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2360 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2365 * Taint values can only be increased
2366 * This means we can safely use a temporary.
2368 static int proc_taint(struct ctl_table
*table
, int write
,
2369 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2372 unsigned long tmptaint
= get_taint();
2375 if (write
&& !capable(CAP_SYS_ADMIN
))
2380 err
= proc_doulongvec_minmax(&t
, write
, buffer
, lenp
, ppos
);
2386 * Poor man's atomic or. Not worth adding a primitive
2387 * to everyone's atomic.h for this
2390 for (i
= 0; i
< BITS_PER_LONG
&& tmptaint
>> i
; i
++) {
2391 if ((tmptaint
>> i
) & 1)
2399 struct do_proc_dointvec_minmax_conv_param
{
2404 static int do_proc_dointvec_minmax_conv(bool *negp
, unsigned long *lvalp
,
2406 int write
, void *data
)
2408 struct do_proc_dointvec_minmax_conv_param
*param
= data
;
2410 int val
= *negp
? -*lvalp
: *lvalp
;
2411 if ((param
->min
&& *param
->min
> val
) ||
2412 (param
->max
&& *param
->max
< val
))
2419 *lvalp
= (unsigned long)-val
;
2422 *lvalp
= (unsigned long)val
;
2429 * proc_dointvec_minmax - read a vector of integers with min/max values
2430 * @table: the sysctl table
2431 * @write: %TRUE if this is a write to the sysctl file
2432 * @buffer: the user buffer
2433 * @lenp: the size of the user buffer
2434 * @ppos: file position
2436 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2437 * values from/to the user buffer, treated as an ASCII string.
2439 * This routine will ensure the values are within the range specified by
2440 * table->extra1 (min) and table->extra2 (max).
2442 * Returns 0 on success.
2444 int proc_dointvec_minmax(struct ctl_table
*table
, int write
,
2445 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2447 struct do_proc_dointvec_minmax_conv_param param
= {
2448 .min
= (int *) table
->extra1
,
2449 .max
= (int *) table
->extra2
,
2451 return do_proc_dointvec(table
, write
, buffer
, lenp
, ppos
,
2452 do_proc_dointvec_minmax_conv
, ¶m
);
2455 static int __do_proc_doulongvec_minmax(void *data
, struct ctl_table
*table
, int write
,
2456 void __user
*buffer
,
2457 size_t *lenp
, loff_t
*ppos
,
2458 unsigned long convmul
,
2459 unsigned long convdiv
)
2461 unsigned long *i
, *min
, *max
;
2462 int vleft
, first
= 1, err
= 0;
2463 unsigned long page
= 0;
2467 if (!data
|| !table
->maxlen
|| !*lenp
|| (*ppos
&& !write
)) {
2472 i
= (unsigned long *) data
;
2473 min
= (unsigned long *) table
->extra1
;
2474 max
= (unsigned long *) table
->extra2
;
2475 vleft
= table
->maxlen
/ sizeof(unsigned long);
2479 if (left
> PAGE_SIZE
- 1)
2480 left
= PAGE_SIZE
- 1;
2481 page
= __get_free_page(GFP_TEMPORARY
);
2482 kbuf
= (char *) page
;
2485 if (copy_from_user(kbuf
, buffer
, left
)) {
2492 for (; left
&& vleft
--; i
++, min
++, max
++, first
=0) {
2498 left
-= proc_skip_spaces(&kbuf
);
2500 err
= proc_get_long(&kbuf
, &left
, &val
, &neg
,
2502 sizeof(proc_wspace_sep
), NULL
);
2507 if ((min
&& val
< *min
) || (max
&& val
> *max
))
2511 val
= convdiv
* (*i
) / convmul
;
2513 err
= proc_put_char(&buffer
, &left
, '\t');
2514 err
= proc_put_long(&buffer
, &left
, val
, false);
2520 if (!write
&& !first
&& left
&& !err
)
2521 err
= proc_put_char(&buffer
, &left
, '\n');
2523 left
-= proc_skip_spaces(&kbuf
);
2528 return err
? : -EINVAL
;
2535 static int do_proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2536 void __user
*buffer
,
2537 size_t *lenp
, loff_t
*ppos
,
2538 unsigned long convmul
,
2539 unsigned long convdiv
)
2541 return __do_proc_doulongvec_minmax(table
->data
, table
, write
,
2542 buffer
, lenp
, ppos
, convmul
, convdiv
);
2546 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2547 * @table: the sysctl table
2548 * @write: %TRUE if this is a write to the sysctl file
2549 * @buffer: the user buffer
2550 * @lenp: the size of the user buffer
2551 * @ppos: file position
2553 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2554 * values from/to the user buffer, treated as an ASCII string.
2556 * This routine will ensure the values are within the range specified by
2557 * table->extra1 (min) and table->extra2 (max).
2559 * Returns 0 on success.
2561 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2562 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2564 return do_proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
, 1l, 1l);
2568 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2569 * @table: the sysctl table
2570 * @write: %TRUE if this is a write to the sysctl file
2571 * @buffer: the user buffer
2572 * @lenp: the size of the user buffer
2573 * @ppos: file position
2575 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2576 * values from/to the user buffer, treated as an ASCII string. The values
2577 * are treated as milliseconds, and converted to jiffies when they are stored.
2579 * This routine will ensure the values are within the range specified by
2580 * table->extra1 (min) and table->extra2 (max).
2582 * Returns 0 on success.
2584 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2585 void __user
*buffer
,
2586 size_t *lenp
, loff_t
*ppos
)
2588 return do_proc_doulongvec_minmax(table
, write
, buffer
,
2589 lenp
, ppos
, HZ
, 1000l);
2593 static int do_proc_dointvec_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2595 int write
, void *data
)
2598 if (*lvalp
> LONG_MAX
/ HZ
)
2600 *valp
= *negp
? -(*lvalp
*HZ
) : (*lvalp
*HZ
);
2606 lval
= (unsigned long)-val
;
2609 lval
= (unsigned long)val
;
2616 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2618 int write
, void *data
)
2621 if (USER_HZ
< HZ
&& *lvalp
> (LONG_MAX
/ HZ
) * USER_HZ
)
2623 *valp
= clock_t_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2629 lval
= (unsigned long)-val
;
2632 lval
= (unsigned long)val
;
2634 *lvalp
= jiffies_to_clock_t(lval
);
2639 static int do_proc_dointvec_ms_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2641 int write
, void *data
)
2644 *valp
= msecs_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2650 lval
= (unsigned long)-val
;
2653 lval
= (unsigned long)val
;
2655 *lvalp
= jiffies_to_msecs(lval
);
2661 * proc_dointvec_jiffies - read a vector of integers as seconds
2662 * @table: the sysctl table
2663 * @write: %TRUE if this is a write to the sysctl file
2664 * @buffer: the user buffer
2665 * @lenp: the size of the user buffer
2666 * @ppos: file position
2668 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2669 * values from/to the user buffer, treated as an ASCII string.
2670 * The values read are assumed to be in seconds, and are converted into
2673 * Returns 0 on success.
2675 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
,
2676 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2678 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2679 do_proc_dointvec_jiffies_conv
,NULL
);
2683 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2684 * @table: the sysctl table
2685 * @write: %TRUE if this is a write to the sysctl file
2686 * @buffer: the user buffer
2687 * @lenp: the size of the user buffer
2688 * @ppos: pointer to the file position
2690 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2691 * values from/to the user buffer, treated as an ASCII string.
2692 * The values read are assumed to be in 1/USER_HZ seconds, and
2693 * are converted into jiffies.
2695 * Returns 0 on success.
2697 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
,
2698 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2700 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2701 do_proc_dointvec_userhz_jiffies_conv
,NULL
);
2705 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2706 * @table: the sysctl table
2707 * @write: %TRUE if this is a write to the sysctl file
2708 * @buffer: the user buffer
2709 * @lenp: the size of the user buffer
2710 * @ppos: file position
2711 * @ppos: the current position in the file
2713 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2714 * values from/to the user buffer, treated as an ASCII string.
2715 * The values read are assumed to be in 1/1000 seconds, and
2716 * are converted into jiffies.
2718 * Returns 0 on success.
2720 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
,
2721 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2723 return do_proc_dointvec(table
, write
, buffer
, lenp
, ppos
,
2724 do_proc_dointvec_ms_jiffies_conv
, NULL
);
2727 static int proc_do_cad_pid(struct ctl_table
*table
, int write
,
2728 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2730 struct pid
*new_pid
;
2734 tmp
= pid_vnr(cad_pid
);
2736 r
= __do_proc_dointvec(&tmp
, table
, write
, buffer
,
2737 lenp
, ppos
, NULL
, NULL
);
2741 new_pid
= find_get_pid(tmp
);
2745 put_pid(xchg(&cad_pid
, new_pid
));
2750 * proc_do_large_bitmap - read/write from/to a large bitmap
2751 * @table: the sysctl table
2752 * @write: %TRUE if this is a write to the sysctl file
2753 * @buffer: the user buffer
2754 * @lenp: the size of the user buffer
2755 * @ppos: file position
2757 * The bitmap is stored at table->data and the bitmap length (in bits)
2760 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2761 * large bitmaps may be represented in a compact manner. Writing into
2762 * the file will clear the bitmap then update it with the given input.
2764 * Returns 0 on success.
2766 int proc_do_large_bitmap(struct ctl_table
*table
, int write
,
2767 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2771 size_t left
= *lenp
;
2772 unsigned long bitmap_len
= table
->maxlen
;
2773 unsigned long *bitmap
= (unsigned long *) table
->data
;
2774 unsigned long *tmp_bitmap
= NULL
;
2775 char tr_a
[] = { '-', ',', '\n' }, tr_b
[] = { ',', '\n', 0 }, c
;
2777 if (!bitmap_len
|| !left
|| (*ppos
&& !write
)) {
2783 unsigned long page
= 0;
2786 if (left
> PAGE_SIZE
- 1)
2787 left
= PAGE_SIZE
- 1;
2789 page
= __get_free_page(GFP_TEMPORARY
);
2790 kbuf
= (char *) page
;
2793 if (copy_from_user(kbuf
, buffer
, left
)) {
2799 tmp_bitmap
= kzalloc(BITS_TO_LONGS(bitmap_len
) * sizeof(unsigned long),
2805 proc_skip_char(&kbuf
, &left
, '\n');
2806 while (!err
&& left
) {
2807 unsigned long val_a
, val_b
;
2810 err
= proc_get_long(&kbuf
, &left
, &val_a
, &neg
, tr_a
,
2814 if (val_a
>= bitmap_len
|| neg
) {
2826 err
= proc_get_long(&kbuf
, &left
, &val_b
,
2827 &neg
, tr_b
, sizeof(tr_b
),
2831 if (val_b
>= bitmap_len
|| neg
||
2842 while (val_a
<= val_b
)
2843 set_bit(val_a
++, tmp_bitmap
);
2846 proc_skip_char(&kbuf
, &left
, '\n');
2850 unsigned long bit_a
, bit_b
= 0;
2853 bit_a
= find_next_bit(bitmap
, bitmap_len
, bit_b
);
2854 if (bit_a
>= bitmap_len
)
2856 bit_b
= find_next_zero_bit(bitmap
, bitmap_len
,
2860 err
= proc_put_char(&buffer
, &left
, ',');
2864 err
= proc_put_long(&buffer
, &left
, bit_a
, false);
2867 if (bit_a
!= bit_b
) {
2868 err
= proc_put_char(&buffer
, &left
, '-');
2871 err
= proc_put_long(&buffer
, &left
, bit_b
, false);
2879 err
= proc_put_char(&buffer
, &left
, '\n');
2885 bitmap_or(bitmap
, bitmap
, tmp_bitmap
, bitmap_len
);
2887 memcpy(bitmap
, tmp_bitmap
,
2888 BITS_TO_LONGS(bitmap_len
) * sizeof(unsigned long));
2900 #else /* CONFIG_PROC_FS */
2902 int proc_dostring(struct ctl_table
*table
, int write
,
2903 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2908 int proc_dointvec(struct ctl_table
*table
, int write
,
2909 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2914 int proc_dointvec_minmax(struct ctl_table
*table
, int write
,
2915 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2920 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
,
2921 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2926 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
,
2927 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2932 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
,
2933 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2938 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2939 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2944 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2945 void __user
*buffer
,
2946 size_t *lenp
, loff_t
*ppos
)
2952 #endif /* CONFIG_PROC_FS */
2955 * No sense putting this after each symbol definition, twice,
2956 * exception granted :-)
2958 EXPORT_SYMBOL(proc_dointvec
);
2959 EXPORT_SYMBOL(proc_dointvec_jiffies
);
2960 EXPORT_SYMBOL(proc_dointvec_minmax
);
2961 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies
);
2962 EXPORT_SYMBOL(proc_dointvec_ms_jiffies
);
2963 EXPORT_SYMBOL(proc_dostring
);
2964 EXPORT_SYMBOL(proc_doulongvec_minmax
);
2965 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax
);
2966 EXPORT_SYMBOL(register_sysctl_table
);
2967 EXPORT_SYMBOL(register_sysctl_paths
);
2968 EXPORT_SYMBOL(unregister_sysctl_table
);