buddy: clarify comments describing buddy merge
[linux-2.6/mini2440.git] / kernel / sysctl.c
blob1f7b3b76a166c00d8dc94e8e6abe35ba2d1e708f
1 /*
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
12 * Horn.
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
16 * Wendling.
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>
22 #include <linux/mm.h>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/ctype.h>
29 #include <linux/utsname.h>
30 #include <linux/smp_lock.h>
31 #include <linux/fs.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/hugetlb.h>
40 #include <linux/initrd.h>
41 #include <linux/key.h>
42 #include <linux/times.h>
43 #include <linux/limits.h>
44 #include <linux/dcache.h>
45 #include <linux/syscalls.h>
46 #include <linux/vmstat.h>
47 #include <linux/nfs_fs.h>
48 #include <linux/acpi.h>
49 #include <linux/reboot.h>
50 #include <linux/ftrace.h>
52 #include <asm/uaccess.h>
53 #include <asm/processor.h>
55 #ifdef CONFIG_X86
56 #include <asm/nmi.h>
57 #include <asm/stacktrace.h>
58 #include <asm/io.h>
59 #endif
61 static int deprecated_sysctl_warning(struct __sysctl_args *args);
63 #if defined(CONFIG_SYSCTL)
65 /* External variables not in a header file. */
66 extern int C_A_D;
67 extern int print_fatal_signals;
68 extern int sysctl_overcommit_memory;
69 extern int sysctl_overcommit_ratio;
70 extern int sysctl_panic_on_oom;
71 extern int sysctl_oom_kill_allocating_task;
72 extern int sysctl_oom_dump_tasks;
73 extern int max_threads;
74 extern int core_uses_pid;
75 extern int suid_dumpable;
76 extern char core_pattern[];
77 extern int pid_max;
78 extern int min_free_kbytes;
79 extern int pid_max_min, pid_max_max;
80 extern int sysctl_drop_caches;
81 extern int percpu_pagelist_fraction;
82 extern int compat_log;
83 extern int maps_protect;
84 extern int latencytop_enabled;
85 extern int sysctl_nr_open_min, sysctl_nr_open_max;
86 #ifdef CONFIG_RCU_TORTURE_TEST
87 extern int rcutorture_runnable;
88 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
90 /* Constants used for minimum and maximum */
91 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP)
92 static int one = 1;
93 #endif
95 #ifdef CONFIG_DETECT_SOFTLOCKUP
96 static int sixty = 60;
97 static int neg_one = -1;
98 #endif
100 #ifdef CONFIG_MMU
101 static int two = 2;
102 #endif
104 static int zero;
105 static int one_hundred = 100;
107 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
108 static int maxolduid = 65535;
109 static int minolduid;
110 static int min_percpu_pagelist_fract = 8;
112 static int ngroups_max = NGROUPS_MAX;
114 #ifdef CONFIG_MODULES
115 extern char modprobe_path[];
116 #endif
117 #ifdef CONFIG_CHR_DEV_SG
118 extern int sg_big_buff;
119 #endif
121 #ifdef __sparc__
122 extern char reboot_command [];
123 extern int stop_a_enabled;
124 extern int scons_pwroff;
125 #endif
127 #ifdef __hppa__
128 extern int pwrsw_enabled;
129 extern int unaligned_enabled;
130 #endif
132 #ifdef CONFIG_S390
133 #ifdef CONFIG_MATHEMU
134 extern int sysctl_ieee_emulation_warnings;
135 #endif
136 extern int sysctl_userprocess_debug;
137 extern int spin_retry;
138 #endif
140 #ifdef CONFIG_BSD_PROCESS_ACCT
141 extern int acct_parm[];
142 #endif
144 #ifdef CONFIG_IA64
145 extern int no_unaligned_warning;
146 #endif
148 #ifdef CONFIG_RT_MUTEXES
149 extern int max_lock_depth;
150 #endif
152 #ifdef CONFIG_PROC_SYSCTL
153 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
154 void __user *buffer, size_t *lenp, loff_t *ppos);
155 static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
156 void __user *buffer, size_t *lenp, loff_t *ppos);
157 #endif
159 static struct ctl_table root_table[];
160 static struct ctl_table_root sysctl_table_root;
161 static struct ctl_table_header root_table_header = {
162 .ctl_table = root_table,
163 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.header_list),
164 .root = &sysctl_table_root,
166 static struct ctl_table_root sysctl_table_root = {
167 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
168 .header_list = LIST_HEAD_INIT(root_table_header.ctl_entry),
171 static struct ctl_table kern_table[];
172 static struct ctl_table vm_table[];
173 static struct ctl_table fs_table[];
174 static struct ctl_table debug_table[];
175 static struct ctl_table dev_table[];
176 extern struct ctl_table random_table[];
177 #ifdef CONFIG_INOTIFY_USER
178 extern struct ctl_table inotify_table[];
179 #endif
181 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
182 int sysctl_legacy_va_layout;
183 #endif
185 extern int prove_locking;
186 extern int lock_stat;
188 /* The default sysctl tables: */
190 static struct ctl_table root_table[] = {
192 .ctl_name = CTL_KERN,
193 .procname = "kernel",
194 .mode = 0555,
195 .child = kern_table,
198 .ctl_name = CTL_VM,
199 .procname = "vm",
200 .mode = 0555,
201 .child = vm_table,
204 .ctl_name = CTL_FS,
205 .procname = "fs",
206 .mode = 0555,
207 .child = fs_table,
210 .ctl_name = CTL_DEBUG,
211 .procname = "debug",
212 .mode = 0555,
213 .child = debug_table,
216 .ctl_name = CTL_DEV,
217 .procname = "dev",
218 .mode = 0555,
219 .child = dev_table,
222 * NOTE: do not add new entries to this table unless you have read
223 * Documentation/sysctl/ctl_unnumbered.txt
225 { .ctl_name = 0 }
228 #ifdef CONFIG_SCHED_DEBUG
229 static int min_sched_granularity_ns = 100000; /* 100 usecs */
230 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
231 static int min_wakeup_granularity_ns; /* 0 usecs */
232 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
233 #endif
235 static struct ctl_table kern_table[] = {
236 #ifdef CONFIG_SCHED_DEBUG
238 .ctl_name = CTL_UNNUMBERED,
239 .procname = "sched_min_granularity_ns",
240 .data = &sysctl_sched_min_granularity,
241 .maxlen = sizeof(unsigned int),
242 .mode = 0644,
243 .proc_handler = &sched_nr_latency_handler,
244 .strategy = &sysctl_intvec,
245 .extra1 = &min_sched_granularity_ns,
246 .extra2 = &max_sched_granularity_ns,
249 .ctl_name = CTL_UNNUMBERED,
250 .procname = "sched_latency_ns",
251 .data = &sysctl_sched_latency,
252 .maxlen = sizeof(unsigned int),
253 .mode = 0644,
254 .proc_handler = &sched_nr_latency_handler,
255 .strategy = &sysctl_intvec,
256 .extra1 = &min_sched_granularity_ns,
257 .extra2 = &max_sched_granularity_ns,
260 .ctl_name = CTL_UNNUMBERED,
261 .procname = "sched_wakeup_granularity_ns",
262 .data = &sysctl_sched_wakeup_granularity,
263 .maxlen = sizeof(unsigned int),
264 .mode = 0644,
265 .proc_handler = &proc_dointvec_minmax,
266 .strategy = &sysctl_intvec,
267 .extra1 = &min_wakeup_granularity_ns,
268 .extra2 = &max_wakeup_granularity_ns,
271 .ctl_name = CTL_UNNUMBERED,
272 .procname = "sched_shares_ratelimit",
273 .data = &sysctl_sched_shares_ratelimit,
274 .maxlen = sizeof(unsigned int),
275 .mode = 0644,
276 .proc_handler = &proc_dointvec,
279 .ctl_name = CTL_UNNUMBERED,
280 .procname = "sched_child_runs_first",
281 .data = &sysctl_sched_child_runs_first,
282 .maxlen = sizeof(unsigned int),
283 .mode = 0644,
284 .proc_handler = &proc_dointvec,
287 .ctl_name = CTL_UNNUMBERED,
288 .procname = "sched_features",
289 .data = &sysctl_sched_features,
290 .maxlen = sizeof(unsigned int),
291 .mode = 0644,
292 .proc_handler = &proc_dointvec,
295 .ctl_name = CTL_UNNUMBERED,
296 .procname = "sched_migration_cost",
297 .data = &sysctl_sched_migration_cost,
298 .maxlen = sizeof(unsigned int),
299 .mode = 0644,
300 .proc_handler = &proc_dointvec,
303 .ctl_name = CTL_UNNUMBERED,
304 .procname = "sched_nr_migrate",
305 .data = &sysctl_sched_nr_migrate,
306 .maxlen = sizeof(unsigned int),
307 .mode = 0644,
308 .proc_handler = &proc_dointvec,
310 #endif
312 .ctl_name = CTL_UNNUMBERED,
313 .procname = "sched_rt_period_us",
314 .data = &sysctl_sched_rt_period,
315 .maxlen = sizeof(unsigned int),
316 .mode = 0644,
317 .proc_handler = &sched_rt_handler,
320 .ctl_name = CTL_UNNUMBERED,
321 .procname = "sched_rt_runtime_us",
322 .data = &sysctl_sched_rt_runtime,
323 .maxlen = sizeof(int),
324 .mode = 0644,
325 .proc_handler = &sched_rt_handler,
328 .ctl_name = CTL_UNNUMBERED,
329 .procname = "sched_compat_yield",
330 .data = &sysctl_sched_compat_yield,
331 .maxlen = sizeof(unsigned int),
332 .mode = 0644,
333 .proc_handler = &proc_dointvec,
335 #ifdef CONFIG_PROVE_LOCKING
337 .ctl_name = CTL_UNNUMBERED,
338 .procname = "prove_locking",
339 .data = &prove_locking,
340 .maxlen = sizeof(int),
341 .mode = 0644,
342 .proc_handler = &proc_dointvec,
344 #endif
345 #ifdef CONFIG_LOCK_STAT
347 .ctl_name = CTL_UNNUMBERED,
348 .procname = "lock_stat",
349 .data = &lock_stat,
350 .maxlen = sizeof(int),
351 .mode = 0644,
352 .proc_handler = &proc_dointvec,
354 #endif
356 .ctl_name = KERN_PANIC,
357 .procname = "panic",
358 .data = &panic_timeout,
359 .maxlen = sizeof(int),
360 .mode = 0644,
361 .proc_handler = &proc_dointvec,
364 .ctl_name = KERN_CORE_USES_PID,
365 .procname = "core_uses_pid",
366 .data = &core_uses_pid,
367 .maxlen = sizeof(int),
368 .mode = 0644,
369 .proc_handler = &proc_dointvec,
372 .ctl_name = KERN_CORE_PATTERN,
373 .procname = "core_pattern",
374 .data = core_pattern,
375 .maxlen = CORENAME_MAX_SIZE,
376 .mode = 0644,
377 .proc_handler = &proc_dostring,
378 .strategy = &sysctl_string,
380 #ifdef CONFIG_PROC_SYSCTL
382 .procname = "tainted",
383 .data = &tainted,
384 .maxlen = sizeof(int),
385 .mode = 0644,
386 .proc_handler = &proc_dointvec_taint,
388 #endif
389 #ifdef CONFIG_LATENCYTOP
391 .procname = "latencytop",
392 .data = &latencytop_enabled,
393 .maxlen = sizeof(int),
394 .mode = 0644,
395 .proc_handler = &proc_dointvec,
397 #endif
398 #ifdef CONFIG_BLK_DEV_INITRD
400 .ctl_name = KERN_REALROOTDEV,
401 .procname = "real-root-dev",
402 .data = &real_root_dev,
403 .maxlen = sizeof(int),
404 .mode = 0644,
405 .proc_handler = &proc_dointvec,
407 #endif
409 .ctl_name = CTL_UNNUMBERED,
410 .procname = "print-fatal-signals",
411 .data = &print_fatal_signals,
412 .maxlen = sizeof(int),
413 .mode = 0644,
414 .proc_handler = &proc_dointvec,
416 #ifdef __sparc__
418 .ctl_name = KERN_SPARC_REBOOT,
419 .procname = "reboot-cmd",
420 .data = reboot_command,
421 .maxlen = 256,
422 .mode = 0644,
423 .proc_handler = &proc_dostring,
424 .strategy = &sysctl_string,
427 .ctl_name = KERN_SPARC_STOP_A,
428 .procname = "stop-a",
429 .data = &stop_a_enabled,
430 .maxlen = sizeof (int),
431 .mode = 0644,
432 .proc_handler = &proc_dointvec,
435 .ctl_name = KERN_SPARC_SCONS_PWROFF,
436 .procname = "scons-poweroff",
437 .data = &scons_pwroff,
438 .maxlen = sizeof (int),
439 .mode = 0644,
440 .proc_handler = &proc_dointvec,
442 #endif
443 #ifdef __hppa__
445 .ctl_name = KERN_HPPA_PWRSW,
446 .procname = "soft-power",
447 .data = &pwrsw_enabled,
448 .maxlen = sizeof (int),
449 .mode = 0644,
450 .proc_handler = &proc_dointvec,
453 .ctl_name = KERN_HPPA_UNALIGNED,
454 .procname = "unaligned-trap",
455 .data = &unaligned_enabled,
456 .maxlen = sizeof (int),
457 .mode = 0644,
458 .proc_handler = &proc_dointvec,
460 #endif
462 .ctl_name = KERN_CTLALTDEL,
463 .procname = "ctrl-alt-del",
464 .data = &C_A_D,
465 .maxlen = sizeof(int),
466 .mode = 0644,
467 .proc_handler = &proc_dointvec,
469 #ifdef CONFIG_FTRACE
471 .ctl_name = CTL_UNNUMBERED,
472 .procname = "ftrace_enabled",
473 .data = &ftrace_enabled,
474 .maxlen = sizeof(int),
475 .mode = 0644,
476 .proc_handler = &ftrace_enable_sysctl,
478 #endif
479 #ifdef CONFIG_MODULES
481 .ctl_name = KERN_MODPROBE,
482 .procname = "modprobe",
483 .data = &modprobe_path,
484 .maxlen = KMOD_PATH_LEN,
485 .mode = 0644,
486 .proc_handler = &proc_dostring,
487 .strategy = &sysctl_string,
489 #endif
490 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
492 .ctl_name = KERN_HOTPLUG,
493 .procname = "hotplug",
494 .data = &uevent_helper,
495 .maxlen = UEVENT_HELPER_PATH_LEN,
496 .mode = 0644,
497 .proc_handler = &proc_dostring,
498 .strategy = &sysctl_string,
500 #endif
501 #ifdef CONFIG_CHR_DEV_SG
503 .ctl_name = KERN_SG_BIG_BUFF,
504 .procname = "sg-big-buff",
505 .data = &sg_big_buff,
506 .maxlen = sizeof (int),
507 .mode = 0444,
508 .proc_handler = &proc_dointvec,
510 #endif
511 #ifdef CONFIG_BSD_PROCESS_ACCT
513 .ctl_name = KERN_ACCT,
514 .procname = "acct",
515 .data = &acct_parm,
516 .maxlen = 3*sizeof(int),
517 .mode = 0644,
518 .proc_handler = &proc_dointvec,
520 #endif
521 #ifdef CONFIG_MAGIC_SYSRQ
523 .ctl_name = KERN_SYSRQ,
524 .procname = "sysrq",
525 .data = &__sysrq_enabled,
526 .maxlen = sizeof (int),
527 .mode = 0644,
528 .proc_handler = &proc_dointvec,
530 #endif
531 #ifdef CONFIG_PROC_SYSCTL
533 .procname = "cad_pid",
534 .data = NULL,
535 .maxlen = sizeof (int),
536 .mode = 0600,
537 .proc_handler = &proc_do_cad_pid,
539 #endif
541 .ctl_name = KERN_MAX_THREADS,
542 .procname = "threads-max",
543 .data = &max_threads,
544 .maxlen = sizeof(int),
545 .mode = 0644,
546 .proc_handler = &proc_dointvec,
549 .ctl_name = KERN_RANDOM,
550 .procname = "random",
551 .mode = 0555,
552 .child = random_table,
555 .ctl_name = KERN_OVERFLOWUID,
556 .procname = "overflowuid",
557 .data = &overflowuid,
558 .maxlen = sizeof(int),
559 .mode = 0644,
560 .proc_handler = &proc_dointvec_minmax,
561 .strategy = &sysctl_intvec,
562 .extra1 = &minolduid,
563 .extra2 = &maxolduid,
566 .ctl_name = KERN_OVERFLOWGID,
567 .procname = "overflowgid",
568 .data = &overflowgid,
569 .maxlen = sizeof(int),
570 .mode = 0644,
571 .proc_handler = &proc_dointvec_minmax,
572 .strategy = &sysctl_intvec,
573 .extra1 = &minolduid,
574 .extra2 = &maxolduid,
576 #ifdef CONFIG_S390
577 #ifdef CONFIG_MATHEMU
579 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
580 .procname = "ieee_emulation_warnings",
581 .data = &sysctl_ieee_emulation_warnings,
582 .maxlen = sizeof(int),
583 .mode = 0644,
584 .proc_handler = &proc_dointvec,
586 #endif
588 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
589 .procname = "userprocess_debug",
590 .data = &sysctl_userprocess_debug,
591 .maxlen = sizeof(int),
592 .mode = 0644,
593 .proc_handler = &proc_dointvec,
595 #endif
597 .ctl_name = KERN_PIDMAX,
598 .procname = "pid_max",
599 .data = &pid_max,
600 .maxlen = sizeof (int),
601 .mode = 0644,
602 .proc_handler = &proc_dointvec_minmax,
603 .strategy = sysctl_intvec,
604 .extra1 = &pid_max_min,
605 .extra2 = &pid_max_max,
608 .ctl_name = KERN_PANIC_ON_OOPS,
609 .procname = "panic_on_oops",
610 .data = &panic_on_oops,
611 .maxlen = sizeof(int),
612 .mode = 0644,
613 .proc_handler = &proc_dointvec,
615 #if defined CONFIG_PRINTK
617 .ctl_name = KERN_PRINTK,
618 .procname = "printk",
619 .data = &console_loglevel,
620 .maxlen = 4*sizeof(int),
621 .mode = 0644,
622 .proc_handler = &proc_dointvec,
625 .ctl_name = KERN_PRINTK_RATELIMIT,
626 .procname = "printk_ratelimit",
627 .data = &printk_ratelimit_jiffies,
628 .maxlen = sizeof(int),
629 .mode = 0644,
630 .proc_handler = &proc_dointvec_jiffies,
631 .strategy = &sysctl_jiffies,
634 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
635 .procname = "printk_ratelimit_burst",
636 .data = &printk_ratelimit_burst,
637 .maxlen = sizeof(int),
638 .mode = 0644,
639 .proc_handler = &proc_dointvec,
641 #endif
643 .ctl_name = KERN_NGROUPS_MAX,
644 .procname = "ngroups_max",
645 .data = &ngroups_max,
646 .maxlen = sizeof (int),
647 .mode = 0444,
648 .proc_handler = &proc_dointvec,
650 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
652 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
653 .procname = "unknown_nmi_panic",
654 .data = &unknown_nmi_panic,
655 .maxlen = sizeof (int),
656 .mode = 0644,
657 .proc_handler = &proc_dointvec,
660 .procname = "nmi_watchdog",
661 .data = &nmi_watchdog_enabled,
662 .maxlen = sizeof (int),
663 .mode = 0644,
664 .proc_handler = &proc_nmi_enabled,
666 #endif
667 #if defined(CONFIG_X86)
669 .ctl_name = KERN_PANIC_ON_NMI,
670 .procname = "panic_on_unrecovered_nmi",
671 .data = &panic_on_unrecovered_nmi,
672 .maxlen = sizeof(int),
673 .mode = 0644,
674 .proc_handler = &proc_dointvec,
677 .ctl_name = KERN_BOOTLOADER_TYPE,
678 .procname = "bootloader_type",
679 .data = &bootloader_type,
680 .maxlen = sizeof (int),
681 .mode = 0444,
682 .proc_handler = &proc_dointvec,
685 .ctl_name = CTL_UNNUMBERED,
686 .procname = "kstack_depth_to_print",
687 .data = &kstack_depth_to_print,
688 .maxlen = sizeof(int),
689 .mode = 0644,
690 .proc_handler = &proc_dointvec,
693 .ctl_name = CTL_UNNUMBERED,
694 .procname = "io_delay_type",
695 .data = &io_delay_type,
696 .maxlen = sizeof(int),
697 .mode = 0644,
698 .proc_handler = &proc_dointvec,
700 #endif
701 #if defined(CONFIG_MMU)
703 .ctl_name = KERN_RANDOMIZE,
704 .procname = "randomize_va_space",
705 .data = &randomize_va_space,
706 .maxlen = sizeof(int),
707 .mode = 0644,
708 .proc_handler = &proc_dointvec,
710 #endif
711 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
713 .ctl_name = KERN_SPIN_RETRY,
714 .procname = "spin_retry",
715 .data = &spin_retry,
716 .maxlen = sizeof (int),
717 .mode = 0644,
718 .proc_handler = &proc_dointvec,
720 #endif
721 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
723 .procname = "acpi_video_flags",
724 .data = &acpi_realmode_flags,
725 .maxlen = sizeof (unsigned long),
726 .mode = 0644,
727 .proc_handler = &proc_doulongvec_minmax,
729 #endif
730 #ifdef CONFIG_IA64
732 .ctl_name = KERN_IA64_UNALIGNED,
733 .procname = "ignore-unaligned-usertrap",
734 .data = &no_unaligned_warning,
735 .maxlen = sizeof (int),
736 .mode = 0644,
737 .proc_handler = &proc_dointvec,
739 #endif
740 #ifdef CONFIG_DETECT_SOFTLOCKUP
742 .ctl_name = CTL_UNNUMBERED,
743 .procname = "softlockup_panic",
744 .data = &softlockup_panic,
745 .maxlen = sizeof(int),
746 .mode = 0644,
747 .proc_handler = &proc_dointvec_minmax,
748 .strategy = &sysctl_intvec,
749 .extra1 = &zero,
750 .extra2 = &one,
753 .ctl_name = CTL_UNNUMBERED,
754 .procname = "softlockup_thresh",
755 .data = &softlockup_thresh,
756 .maxlen = sizeof(int),
757 .mode = 0644,
758 .proc_handler = &proc_dointvec_minmax,
759 .strategy = &sysctl_intvec,
760 .extra1 = &neg_one,
761 .extra2 = &sixty,
764 .ctl_name = CTL_UNNUMBERED,
765 .procname = "hung_task_check_count",
766 .data = &sysctl_hung_task_check_count,
767 .maxlen = sizeof(unsigned long),
768 .mode = 0644,
769 .proc_handler = &proc_doulongvec_minmax,
770 .strategy = &sysctl_intvec,
773 .ctl_name = CTL_UNNUMBERED,
774 .procname = "hung_task_timeout_secs",
775 .data = &sysctl_hung_task_timeout_secs,
776 .maxlen = sizeof(unsigned long),
777 .mode = 0644,
778 .proc_handler = &proc_doulongvec_minmax,
779 .strategy = &sysctl_intvec,
782 .ctl_name = CTL_UNNUMBERED,
783 .procname = "hung_task_warnings",
784 .data = &sysctl_hung_task_warnings,
785 .maxlen = sizeof(unsigned long),
786 .mode = 0644,
787 .proc_handler = &proc_doulongvec_minmax,
788 .strategy = &sysctl_intvec,
790 #endif
791 #ifdef CONFIG_COMPAT
793 .ctl_name = KERN_COMPAT_LOG,
794 .procname = "compat-log",
795 .data = &compat_log,
796 .maxlen = sizeof (int),
797 .mode = 0644,
798 .proc_handler = &proc_dointvec,
800 #endif
801 #ifdef CONFIG_RT_MUTEXES
803 .ctl_name = KERN_MAX_LOCK_DEPTH,
804 .procname = "max_lock_depth",
805 .data = &max_lock_depth,
806 .maxlen = sizeof(int),
807 .mode = 0644,
808 .proc_handler = &proc_dointvec,
810 #endif
811 #ifdef CONFIG_PROC_FS
813 .ctl_name = CTL_UNNUMBERED,
814 .procname = "maps_protect",
815 .data = &maps_protect,
816 .maxlen = sizeof(int),
817 .mode = 0644,
818 .proc_handler = &proc_dointvec,
820 #endif
822 .ctl_name = CTL_UNNUMBERED,
823 .procname = "poweroff_cmd",
824 .data = &poweroff_cmd,
825 .maxlen = POWEROFF_CMD_PATH_LEN,
826 .mode = 0644,
827 .proc_handler = &proc_dostring,
828 .strategy = &sysctl_string,
830 #ifdef CONFIG_KEYS
832 .ctl_name = CTL_UNNUMBERED,
833 .procname = "keys",
834 .mode = 0555,
835 .child = key_sysctls,
837 #endif
838 #ifdef CONFIG_RCU_TORTURE_TEST
840 .ctl_name = CTL_UNNUMBERED,
841 .procname = "rcutorture_runnable",
842 .data = &rcutorture_runnable,
843 .maxlen = sizeof(int),
844 .mode = 0644,
845 .proc_handler = &proc_dointvec,
847 #endif
849 * NOTE: do not add new entries to this table unless you have read
850 * Documentation/sysctl/ctl_unnumbered.txt
852 { .ctl_name = 0 }
855 static struct ctl_table vm_table[] = {
857 .ctl_name = VM_OVERCOMMIT_MEMORY,
858 .procname = "overcommit_memory",
859 .data = &sysctl_overcommit_memory,
860 .maxlen = sizeof(sysctl_overcommit_memory),
861 .mode = 0644,
862 .proc_handler = &proc_dointvec,
865 .ctl_name = VM_PANIC_ON_OOM,
866 .procname = "panic_on_oom",
867 .data = &sysctl_panic_on_oom,
868 .maxlen = sizeof(sysctl_panic_on_oom),
869 .mode = 0644,
870 .proc_handler = &proc_dointvec,
873 .ctl_name = CTL_UNNUMBERED,
874 .procname = "oom_kill_allocating_task",
875 .data = &sysctl_oom_kill_allocating_task,
876 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
877 .mode = 0644,
878 .proc_handler = &proc_dointvec,
881 .ctl_name = CTL_UNNUMBERED,
882 .procname = "oom_dump_tasks",
883 .data = &sysctl_oom_dump_tasks,
884 .maxlen = sizeof(sysctl_oom_dump_tasks),
885 .mode = 0644,
886 .proc_handler = &proc_dointvec,
889 .ctl_name = VM_OVERCOMMIT_RATIO,
890 .procname = "overcommit_ratio",
891 .data = &sysctl_overcommit_ratio,
892 .maxlen = sizeof(sysctl_overcommit_ratio),
893 .mode = 0644,
894 .proc_handler = &proc_dointvec,
897 .ctl_name = VM_PAGE_CLUSTER,
898 .procname = "page-cluster",
899 .data = &page_cluster,
900 .maxlen = sizeof(int),
901 .mode = 0644,
902 .proc_handler = &proc_dointvec,
905 .ctl_name = VM_DIRTY_BACKGROUND,
906 .procname = "dirty_background_ratio",
907 .data = &dirty_background_ratio,
908 .maxlen = sizeof(dirty_background_ratio),
909 .mode = 0644,
910 .proc_handler = &proc_dointvec_minmax,
911 .strategy = &sysctl_intvec,
912 .extra1 = &zero,
913 .extra2 = &one_hundred,
916 .ctl_name = VM_DIRTY_RATIO,
917 .procname = "dirty_ratio",
918 .data = &vm_dirty_ratio,
919 .maxlen = sizeof(vm_dirty_ratio),
920 .mode = 0644,
921 .proc_handler = &dirty_ratio_handler,
922 .strategy = &sysctl_intvec,
923 .extra1 = &zero,
924 .extra2 = &one_hundred,
927 .procname = "dirty_writeback_centisecs",
928 .data = &dirty_writeback_interval,
929 .maxlen = sizeof(dirty_writeback_interval),
930 .mode = 0644,
931 .proc_handler = &dirty_writeback_centisecs_handler,
934 .procname = "dirty_expire_centisecs",
935 .data = &dirty_expire_interval,
936 .maxlen = sizeof(dirty_expire_interval),
937 .mode = 0644,
938 .proc_handler = &proc_dointvec_userhz_jiffies,
941 .ctl_name = VM_NR_PDFLUSH_THREADS,
942 .procname = "nr_pdflush_threads",
943 .data = &nr_pdflush_threads,
944 .maxlen = sizeof nr_pdflush_threads,
945 .mode = 0444 /* read-only*/,
946 .proc_handler = &proc_dointvec,
949 .ctl_name = VM_SWAPPINESS,
950 .procname = "swappiness",
951 .data = &vm_swappiness,
952 .maxlen = sizeof(vm_swappiness),
953 .mode = 0644,
954 .proc_handler = &proc_dointvec_minmax,
955 .strategy = &sysctl_intvec,
956 .extra1 = &zero,
957 .extra2 = &one_hundred,
959 #ifdef CONFIG_HUGETLB_PAGE
961 .procname = "nr_hugepages",
962 .data = &max_huge_pages,
963 .maxlen = sizeof(unsigned long),
964 .mode = 0644,
965 .proc_handler = &hugetlb_sysctl_handler,
966 .extra1 = (void *)&hugetlb_zero,
967 .extra2 = (void *)&hugetlb_infinity,
970 .ctl_name = VM_HUGETLB_GROUP,
971 .procname = "hugetlb_shm_group",
972 .data = &sysctl_hugetlb_shm_group,
973 .maxlen = sizeof(gid_t),
974 .mode = 0644,
975 .proc_handler = &proc_dointvec,
978 .ctl_name = CTL_UNNUMBERED,
979 .procname = "hugepages_treat_as_movable",
980 .data = &hugepages_treat_as_movable,
981 .maxlen = sizeof(int),
982 .mode = 0644,
983 .proc_handler = &hugetlb_treat_movable_handler,
986 .ctl_name = CTL_UNNUMBERED,
987 .procname = "nr_overcommit_hugepages",
988 .data = &sysctl_overcommit_huge_pages,
989 .maxlen = sizeof(sysctl_overcommit_huge_pages),
990 .mode = 0644,
991 .proc_handler = &hugetlb_overcommit_handler,
993 #endif
995 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
996 .procname = "lowmem_reserve_ratio",
997 .data = &sysctl_lowmem_reserve_ratio,
998 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
999 .mode = 0644,
1000 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
1001 .strategy = &sysctl_intvec,
1004 .ctl_name = VM_DROP_PAGECACHE,
1005 .procname = "drop_caches",
1006 .data = &sysctl_drop_caches,
1007 .maxlen = sizeof(int),
1008 .mode = 0644,
1009 .proc_handler = drop_caches_sysctl_handler,
1010 .strategy = &sysctl_intvec,
1013 .ctl_name = VM_MIN_FREE_KBYTES,
1014 .procname = "min_free_kbytes",
1015 .data = &min_free_kbytes,
1016 .maxlen = sizeof(min_free_kbytes),
1017 .mode = 0644,
1018 .proc_handler = &min_free_kbytes_sysctl_handler,
1019 .strategy = &sysctl_intvec,
1020 .extra1 = &zero,
1023 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
1024 .procname = "percpu_pagelist_fraction",
1025 .data = &percpu_pagelist_fraction,
1026 .maxlen = sizeof(percpu_pagelist_fraction),
1027 .mode = 0644,
1028 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1029 .strategy = &sysctl_intvec,
1030 .extra1 = &min_percpu_pagelist_fract,
1032 #ifdef CONFIG_MMU
1034 .ctl_name = VM_MAX_MAP_COUNT,
1035 .procname = "max_map_count",
1036 .data = &sysctl_max_map_count,
1037 .maxlen = sizeof(sysctl_max_map_count),
1038 .mode = 0644,
1039 .proc_handler = &proc_dointvec
1041 #endif
1043 .ctl_name = VM_LAPTOP_MODE,
1044 .procname = "laptop_mode",
1045 .data = &laptop_mode,
1046 .maxlen = sizeof(laptop_mode),
1047 .mode = 0644,
1048 .proc_handler = &proc_dointvec_jiffies,
1049 .strategy = &sysctl_jiffies,
1052 .ctl_name = VM_BLOCK_DUMP,
1053 .procname = "block_dump",
1054 .data = &block_dump,
1055 .maxlen = sizeof(block_dump),
1056 .mode = 0644,
1057 .proc_handler = &proc_dointvec,
1058 .strategy = &sysctl_intvec,
1059 .extra1 = &zero,
1062 .ctl_name = VM_VFS_CACHE_PRESSURE,
1063 .procname = "vfs_cache_pressure",
1064 .data = &sysctl_vfs_cache_pressure,
1065 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1066 .mode = 0644,
1067 .proc_handler = &proc_dointvec,
1068 .strategy = &sysctl_intvec,
1069 .extra1 = &zero,
1071 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1073 .ctl_name = VM_LEGACY_VA_LAYOUT,
1074 .procname = "legacy_va_layout",
1075 .data = &sysctl_legacy_va_layout,
1076 .maxlen = sizeof(sysctl_legacy_va_layout),
1077 .mode = 0644,
1078 .proc_handler = &proc_dointvec,
1079 .strategy = &sysctl_intvec,
1080 .extra1 = &zero,
1082 #endif
1083 #ifdef CONFIG_NUMA
1085 .ctl_name = VM_ZONE_RECLAIM_MODE,
1086 .procname = "zone_reclaim_mode",
1087 .data = &zone_reclaim_mode,
1088 .maxlen = sizeof(zone_reclaim_mode),
1089 .mode = 0644,
1090 .proc_handler = &proc_dointvec,
1091 .strategy = &sysctl_intvec,
1092 .extra1 = &zero,
1095 .ctl_name = VM_MIN_UNMAPPED,
1096 .procname = "min_unmapped_ratio",
1097 .data = &sysctl_min_unmapped_ratio,
1098 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1099 .mode = 0644,
1100 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1101 .strategy = &sysctl_intvec,
1102 .extra1 = &zero,
1103 .extra2 = &one_hundred,
1106 .ctl_name = VM_MIN_SLAB,
1107 .procname = "min_slab_ratio",
1108 .data = &sysctl_min_slab_ratio,
1109 .maxlen = sizeof(sysctl_min_slab_ratio),
1110 .mode = 0644,
1111 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1112 .strategy = &sysctl_intvec,
1113 .extra1 = &zero,
1114 .extra2 = &one_hundred,
1116 #endif
1117 #ifdef CONFIG_SMP
1119 .ctl_name = CTL_UNNUMBERED,
1120 .procname = "stat_interval",
1121 .data = &sysctl_stat_interval,
1122 .maxlen = sizeof(sysctl_stat_interval),
1123 .mode = 0644,
1124 .proc_handler = &proc_dointvec_jiffies,
1125 .strategy = &sysctl_jiffies,
1127 #endif
1128 #ifdef CONFIG_SECURITY
1130 .ctl_name = CTL_UNNUMBERED,
1131 .procname = "mmap_min_addr",
1132 .data = &mmap_min_addr,
1133 .maxlen = sizeof(unsigned long),
1134 .mode = 0644,
1135 .proc_handler = &proc_doulongvec_minmax,
1137 #endif
1138 #ifdef CONFIG_NUMA
1140 .ctl_name = CTL_UNNUMBERED,
1141 .procname = "numa_zonelist_order",
1142 .data = &numa_zonelist_order,
1143 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1144 .mode = 0644,
1145 .proc_handler = &numa_zonelist_order_handler,
1146 .strategy = &sysctl_string,
1148 #endif
1149 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1150 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1152 .ctl_name = VM_VDSO_ENABLED,
1153 .procname = "vdso_enabled",
1154 .data = &vdso_enabled,
1155 .maxlen = sizeof(vdso_enabled),
1156 .mode = 0644,
1157 .proc_handler = &proc_dointvec,
1158 .strategy = &sysctl_intvec,
1159 .extra1 = &zero,
1161 #endif
1162 #ifdef CONFIG_HIGHMEM
1164 .ctl_name = CTL_UNNUMBERED,
1165 .procname = "highmem_is_dirtyable",
1166 .data = &vm_highmem_is_dirtyable,
1167 .maxlen = sizeof(vm_highmem_is_dirtyable),
1168 .mode = 0644,
1169 .proc_handler = &proc_dointvec_minmax,
1170 .strategy = &sysctl_intvec,
1171 .extra1 = &zero,
1172 .extra2 = &one,
1174 #endif
1176 * NOTE: do not add new entries to this table unless you have read
1177 * Documentation/sysctl/ctl_unnumbered.txt
1179 { .ctl_name = 0 }
1182 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1183 static struct ctl_table binfmt_misc_table[] = {
1184 { .ctl_name = 0 }
1186 #endif
1188 static struct ctl_table fs_table[] = {
1190 .ctl_name = FS_NRINODE,
1191 .procname = "inode-nr",
1192 .data = &inodes_stat,
1193 .maxlen = 2*sizeof(int),
1194 .mode = 0444,
1195 .proc_handler = &proc_dointvec,
1198 .ctl_name = FS_STATINODE,
1199 .procname = "inode-state",
1200 .data = &inodes_stat,
1201 .maxlen = 7*sizeof(int),
1202 .mode = 0444,
1203 .proc_handler = &proc_dointvec,
1206 .procname = "file-nr",
1207 .data = &files_stat,
1208 .maxlen = 3*sizeof(int),
1209 .mode = 0444,
1210 .proc_handler = &proc_nr_files,
1213 .ctl_name = FS_MAXFILE,
1214 .procname = "file-max",
1215 .data = &files_stat.max_files,
1216 .maxlen = sizeof(int),
1217 .mode = 0644,
1218 .proc_handler = &proc_dointvec,
1221 .ctl_name = CTL_UNNUMBERED,
1222 .procname = "nr_open",
1223 .data = &sysctl_nr_open,
1224 .maxlen = sizeof(int),
1225 .mode = 0644,
1226 .proc_handler = &proc_dointvec_minmax,
1227 .extra1 = &sysctl_nr_open_min,
1228 .extra2 = &sysctl_nr_open_max,
1231 .ctl_name = FS_DENTRY,
1232 .procname = "dentry-state",
1233 .data = &dentry_stat,
1234 .maxlen = 6*sizeof(int),
1235 .mode = 0444,
1236 .proc_handler = &proc_dointvec,
1239 .ctl_name = FS_OVERFLOWUID,
1240 .procname = "overflowuid",
1241 .data = &fs_overflowuid,
1242 .maxlen = sizeof(int),
1243 .mode = 0644,
1244 .proc_handler = &proc_dointvec_minmax,
1245 .strategy = &sysctl_intvec,
1246 .extra1 = &minolduid,
1247 .extra2 = &maxolduid,
1250 .ctl_name = FS_OVERFLOWGID,
1251 .procname = "overflowgid",
1252 .data = &fs_overflowgid,
1253 .maxlen = sizeof(int),
1254 .mode = 0644,
1255 .proc_handler = &proc_dointvec_minmax,
1256 .strategy = &sysctl_intvec,
1257 .extra1 = &minolduid,
1258 .extra2 = &maxolduid,
1261 .ctl_name = FS_LEASES,
1262 .procname = "leases-enable",
1263 .data = &leases_enable,
1264 .maxlen = sizeof(int),
1265 .mode = 0644,
1266 .proc_handler = &proc_dointvec,
1268 #ifdef CONFIG_DNOTIFY
1270 .ctl_name = FS_DIR_NOTIFY,
1271 .procname = "dir-notify-enable",
1272 .data = &dir_notify_enable,
1273 .maxlen = sizeof(int),
1274 .mode = 0644,
1275 .proc_handler = &proc_dointvec,
1277 #endif
1278 #ifdef CONFIG_MMU
1280 .ctl_name = FS_LEASE_TIME,
1281 .procname = "lease-break-time",
1282 .data = &lease_break_time,
1283 .maxlen = sizeof(int),
1284 .mode = 0644,
1285 .proc_handler = &proc_dointvec_minmax,
1286 .strategy = &sysctl_intvec,
1287 .extra1 = &zero,
1288 .extra2 = &two,
1291 .procname = "aio-nr",
1292 .data = &aio_nr,
1293 .maxlen = sizeof(aio_nr),
1294 .mode = 0444,
1295 .proc_handler = &proc_doulongvec_minmax,
1298 .procname = "aio-max-nr",
1299 .data = &aio_max_nr,
1300 .maxlen = sizeof(aio_max_nr),
1301 .mode = 0644,
1302 .proc_handler = &proc_doulongvec_minmax,
1304 #ifdef CONFIG_INOTIFY_USER
1306 .ctl_name = FS_INOTIFY,
1307 .procname = "inotify",
1308 .mode = 0555,
1309 .child = inotify_table,
1311 #endif
1312 #endif
1314 .ctl_name = KERN_SETUID_DUMPABLE,
1315 .procname = "suid_dumpable",
1316 .data = &suid_dumpable,
1317 .maxlen = sizeof(int),
1318 .mode = 0644,
1319 .proc_handler = &proc_dointvec,
1321 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1323 .ctl_name = CTL_UNNUMBERED,
1324 .procname = "binfmt_misc",
1325 .mode = 0555,
1326 .child = binfmt_misc_table,
1328 #endif
1330 * NOTE: do not add new entries to this table unless you have read
1331 * Documentation/sysctl/ctl_unnumbered.txt
1333 { .ctl_name = 0 }
1336 static struct ctl_table debug_table[] = {
1337 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1339 .ctl_name = CTL_UNNUMBERED,
1340 .procname = "exception-trace",
1341 .data = &show_unhandled_signals,
1342 .maxlen = sizeof(int),
1343 .mode = 0644,
1344 .proc_handler = proc_dointvec
1346 #endif
1347 { .ctl_name = 0 }
1350 static struct ctl_table dev_table[] = {
1351 { .ctl_name = 0 }
1354 static DEFINE_SPINLOCK(sysctl_lock);
1356 /* called under sysctl_lock */
1357 static int use_table(struct ctl_table_header *p)
1359 if (unlikely(p->unregistering))
1360 return 0;
1361 p->used++;
1362 return 1;
1365 /* called under sysctl_lock */
1366 static void unuse_table(struct ctl_table_header *p)
1368 if (!--p->used)
1369 if (unlikely(p->unregistering))
1370 complete(p->unregistering);
1373 /* called under sysctl_lock, will reacquire if has to wait */
1374 static void start_unregistering(struct ctl_table_header *p)
1377 * if p->used is 0, nobody will ever touch that entry again;
1378 * we'll eliminate all paths to it before dropping sysctl_lock
1380 if (unlikely(p->used)) {
1381 struct completion wait;
1382 init_completion(&wait);
1383 p->unregistering = &wait;
1384 spin_unlock(&sysctl_lock);
1385 wait_for_completion(&wait);
1386 spin_lock(&sysctl_lock);
1389 * do not remove from the list until nobody holds it; walking the
1390 * list in do_sysctl() relies on that.
1392 list_del_init(&p->ctl_entry);
1395 void sysctl_head_finish(struct ctl_table_header *head)
1397 if (!head)
1398 return;
1399 spin_lock(&sysctl_lock);
1400 unuse_table(head);
1401 spin_unlock(&sysctl_lock);
1404 static struct list_head *
1405 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1407 struct list_head *header_list;
1408 header_list = &root->header_list;
1409 if (root->lookup)
1410 header_list = root->lookup(root, namespaces);
1411 return header_list;
1414 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1415 struct ctl_table_header *prev)
1417 struct ctl_table_root *root;
1418 struct list_head *header_list;
1419 struct ctl_table_header *head;
1420 struct list_head *tmp;
1422 spin_lock(&sysctl_lock);
1423 if (prev) {
1424 head = prev;
1425 tmp = &prev->ctl_entry;
1426 unuse_table(prev);
1427 goto next;
1429 tmp = &root_table_header.ctl_entry;
1430 for (;;) {
1431 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1433 if (!use_table(head))
1434 goto next;
1435 spin_unlock(&sysctl_lock);
1436 return head;
1437 next:
1438 root = head->root;
1439 tmp = tmp->next;
1440 header_list = lookup_header_list(root, namespaces);
1441 if (tmp != header_list)
1442 continue;
1444 do {
1445 root = list_entry(root->root_list.next,
1446 struct ctl_table_root, root_list);
1447 if (root == &sysctl_table_root)
1448 goto out;
1449 header_list = lookup_header_list(root, namespaces);
1450 } while (list_empty(header_list));
1451 tmp = header_list->next;
1453 out:
1454 spin_unlock(&sysctl_lock);
1455 return NULL;
1458 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1460 return __sysctl_head_next(current->nsproxy, prev);
1463 void register_sysctl_root(struct ctl_table_root *root)
1465 spin_lock(&sysctl_lock);
1466 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1467 spin_unlock(&sysctl_lock);
1470 #ifdef CONFIG_SYSCTL_SYSCALL
1471 /* Perform the actual read/write of a sysctl table entry. */
1472 static int do_sysctl_strategy(struct ctl_table_root *root,
1473 struct ctl_table *table,
1474 int __user *name, int nlen,
1475 void __user *oldval, size_t __user *oldlenp,
1476 void __user *newval, size_t newlen)
1478 int op = 0, rc;
1480 if (oldval)
1481 op |= 004;
1482 if (newval)
1483 op |= 002;
1484 if (sysctl_perm(root, table, op))
1485 return -EPERM;
1487 if (table->strategy) {
1488 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1489 newval, newlen);
1490 if (rc < 0)
1491 return rc;
1492 if (rc > 0)
1493 return 0;
1496 /* If there is no strategy routine, or if the strategy returns
1497 * zero, proceed with automatic r/w */
1498 if (table->data && table->maxlen) {
1499 rc = sysctl_data(table, name, nlen, oldval, oldlenp,
1500 newval, newlen);
1501 if (rc < 0)
1502 return rc;
1504 return 0;
1507 static int parse_table(int __user *name, int nlen,
1508 void __user *oldval, size_t __user *oldlenp,
1509 void __user *newval, size_t newlen,
1510 struct ctl_table_root *root,
1511 struct ctl_table *table)
1513 int n;
1514 repeat:
1515 if (!nlen)
1516 return -ENOTDIR;
1517 if (get_user(n, name))
1518 return -EFAULT;
1519 for ( ; table->ctl_name || table->procname; table++) {
1520 if (!table->ctl_name)
1521 continue;
1522 if (n == table->ctl_name) {
1523 int error;
1524 if (table->child) {
1525 if (sysctl_perm(root, table, 001))
1526 return -EPERM;
1527 name++;
1528 nlen--;
1529 table = table->child;
1530 goto repeat;
1532 error = do_sysctl_strategy(root, table, name, nlen,
1533 oldval, oldlenp,
1534 newval, newlen);
1535 return error;
1538 return -ENOTDIR;
1541 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1542 void __user *newval, size_t newlen)
1544 struct ctl_table_header *head;
1545 int error = -ENOTDIR;
1547 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1548 return -ENOTDIR;
1549 if (oldval) {
1550 int old_len;
1551 if (!oldlenp || get_user(old_len, oldlenp))
1552 return -EFAULT;
1555 for (head = sysctl_head_next(NULL); head;
1556 head = sysctl_head_next(head)) {
1557 error = parse_table(name, nlen, oldval, oldlenp,
1558 newval, newlen,
1559 head->root, head->ctl_table);
1560 if (error != -ENOTDIR) {
1561 sysctl_head_finish(head);
1562 break;
1565 return error;
1568 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1570 struct __sysctl_args tmp;
1571 int error;
1573 if (copy_from_user(&tmp, args, sizeof(tmp)))
1574 return -EFAULT;
1576 error = deprecated_sysctl_warning(&tmp);
1577 if (error)
1578 goto out;
1580 lock_kernel();
1581 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1582 tmp.newval, tmp.newlen);
1583 unlock_kernel();
1584 out:
1585 return error;
1587 #endif /* CONFIG_SYSCTL_SYSCALL */
1590 * sysctl_perm does NOT grant the superuser all rights automatically, because
1591 * some sysctl variables are readonly even to root.
1594 static int test_perm(int mode, int op)
1596 if (!current->euid)
1597 mode >>= 6;
1598 else if (in_egroup_p(0))
1599 mode >>= 3;
1600 if ((mode & op & 0007) == op)
1601 return 0;
1602 return -EACCES;
1605 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1607 int error;
1608 int mode;
1610 error = security_sysctl(table, op);
1611 if (error)
1612 return error;
1614 if (root->permissions)
1615 mode = root->permissions(root, current->nsproxy, table);
1616 else
1617 mode = table->mode;
1619 return test_perm(mode, op);
1622 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1624 for (; table->ctl_name || table->procname; table++) {
1625 table->parent = parent;
1626 if (table->child)
1627 sysctl_set_parent(table, table->child);
1631 static __init int sysctl_init(void)
1633 sysctl_set_parent(NULL, root_table);
1634 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1636 int err;
1637 err = sysctl_check_table(current->nsproxy, root_table);
1639 #endif
1640 return 0;
1643 core_initcall(sysctl_init);
1646 * __register_sysctl_paths - register a sysctl hierarchy
1647 * @root: List of sysctl headers to register on
1648 * @namespaces: Data to compute which lists of sysctl entries are visible
1649 * @path: The path to the directory the sysctl table is in.
1650 * @table: the top-level table structure
1652 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1653 * array. A completely 0 filled entry terminates the table.
1655 * The members of the &struct ctl_table structure are used as follows:
1657 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1658 * must be unique within that level of sysctl
1660 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1661 * enter a sysctl file
1663 * data - a pointer to data for use by proc_handler
1665 * maxlen - the maximum size in bytes of the data
1667 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1669 * child - a pointer to the child sysctl table if this entry is a directory, or
1670 * %NULL.
1672 * proc_handler - the text handler routine (described below)
1674 * strategy - the strategy routine (described below)
1676 * de - for internal use by the sysctl routines
1678 * extra1, extra2 - extra pointers usable by the proc handler routines
1680 * Leaf nodes in the sysctl tree will be represented by a single file
1681 * under /proc; non-leaf nodes will be represented by directories.
1683 * sysctl(2) can automatically manage read and write requests through
1684 * the sysctl table. The data and maxlen fields of the ctl_table
1685 * struct enable minimal validation of the values being written to be
1686 * performed, and the mode field allows minimal authentication.
1688 * More sophisticated management can be enabled by the provision of a
1689 * strategy routine with the table entry. This will be called before
1690 * any automatic read or write of the data is performed.
1692 * The strategy routine may return
1694 * < 0 - Error occurred (error is passed to user process)
1696 * 0 - OK - proceed with automatic read or write.
1698 * > 0 - OK - read or write has been done by the strategy routine, so
1699 * return immediately.
1701 * There must be a proc_handler routine for any terminal nodes
1702 * mirrored under /proc/sys (non-terminals are handled by a built-in
1703 * directory handler). Several default handlers are available to
1704 * cover common cases -
1706 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1707 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1708 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1710 * It is the handler's job to read the input buffer from user memory
1711 * and process it. The handler should return 0 on success.
1713 * This routine returns %NULL on a failure to register, and a pointer
1714 * to the table header on success.
1716 struct ctl_table_header *__register_sysctl_paths(
1717 struct ctl_table_root *root,
1718 struct nsproxy *namespaces,
1719 const struct ctl_path *path, struct ctl_table *table)
1721 struct list_head *header_list;
1722 struct ctl_table_header *header;
1723 struct ctl_table *new, **prevp;
1724 unsigned int n, npath;
1726 /* Count the path components */
1727 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1731 * For each path component, allocate a 2-element ctl_table array.
1732 * The first array element will be filled with the sysctl entry
1733 * for this, the second will be the sentinel (ctl_name == 0).
1735 * We allocate everything in one go so that we don't have to
1736 * worry about freeing additional memory in unregister_sysctl_table.
1738 header = kzalloc(sizeof(struct ctl_table_header) +
1739 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1740 if (!header)
1741 return NULL;
1743 new = (struct ctl_table *) (header + 1);
1745 /* Now connect the dots */
1746 prevp = &header->ctl_table;
1747 for (n = 0; n < npath; ++n, ++path) {
1748 /* Copy the procname */
1749 new->procname = path->procname;
1750 new->ctl_name = path->ctl_name;
1751 new->mode = 0555;
1753 *prevp = new;
1754 prevp = &new->child;
1756 new += 2;
1758 *prevp = table;
1759 header->ctl_table_arg = table;
1761 INIT_LIST_HEAD(&header->ctl_entry);
1762 header->used = 0;
1763 header->unregistering = NULL;
1764 header->root = root;
1765 sysctl_set_parent(NULL, header->ctl_table);
1766 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1767 if (sysctl_check_table(namespaces, header->ctl_table)) {
1768 kfree(header);
1769 return NULL;
1771 #endif
1772 spin_lock(&sysctl_lock);
1773 header_list = lookup_header_list(root, namespaces);
1774 list_add_tail(&header->ctl_entry, header_list);
1775 spin_unlock(&sysctl_lock);
1777 return header;
1781 * register_sysctl_table_path - register a sysctl table hierarchy
1782 * @path: The path to the directory the sysctl table is in.
1783 * @table: the top-level table structure
1785 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1786 * array. A completely 0 filled entry terminates the table.
1788 * See __register_sysctl_paths for more details.
1790 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1791 struct ctl_table *table)
1793 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1794 path, table);
1798 * register_sysctl_table - register a sysctl table hierarchy
1799 * @table: the top-level table structure
1801 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1802 * array. A completely 0 filled entry terminates the table.
1804 * See register_sysctl_paths for more details.
1806 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1808 static const struct ctl_path null_path[] = { {} };
1810 return register_sysctl_paths(null_path, table);
1814 * unregister_sysctl_table - unregister a sysctl table hierarchy
1815 * @header: the header returned from register_sysctl_table
1817 * Unregisters the sysctl table and all children. proc entries may not
1818 * actually be removed until they are no longer used by anyone.
1820 void unregister_sysctl_table(struct ctl_table_header * header)
1822 might_sleep();
1824 if (header == NULL)
1825 return;
1827 spin_lock(&sysctl_lock);
1828 start_unregistering(header);
1829 spin_unlock(&sysctl_lock);
1830 kfree(header);
1833 #else /* !CONFIG_SYSCTL */
1834 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1836 return NULL;
1839 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1840 struct ctl_table *table)
1842 return NULL;
1845 void unregister_sysctl_table(struct ctl_table_header * table)
1849 #endif /* CONFIG_SYSCTL */
1852 * /proc/sys support
1855 #ifdef CONFIG_PROC_SYSCTL
1857 static int _proc_do_string(void* data, int maxlen, int write,
1858 struct file *filp, void __user *buffer,
1859 size_t *lenp, loff_t *ppos)
1861 size_t len;
1862 char __user *p;
1863 char c;
1865 if (!data || !maxlen || !*lenp) {
1866 *lenp = 0;
1867 return 0;
1870 if (write) {
1871 len = 0;
1872 p = buffer;
1873 while (len < *lenp) {
1874 if (get_user(c, p++))
1875 return -EFAULT;
1876 if (c == 0 || c == '\n')
1877 break;
1878 len++;
1880 if (len >= maxlen)
1881 len = maxlen-1;
1882 if(copy_from_user(data, buffer, len))
1883 return -EFAULT;
1884 ((char *) data)[len] = 0;
1885 *ppos += *lenp;
1886 } else {
1887 len = strlen(data);
1888 if (len > maxlen)
1889 len = maxlen;
1891 if (*ppos > len) {
1892 *lenp = 0;
1893 return 0;
1896 data += *ppos;
1897 len -= *ppos;
1899 if (len > *lenp)
1900 len = *lenp;
1901 if (len)
1902 if(copy_to_user(buffer, data, len))
1903 return -EFAULT;
1904 if (len < *lenp) {
1905 if(put_user('\n', ((char __user *) buffer) + len))
1906 return -EFAULT;
1907 len++;
1909 *lenp = len;
1910 *ppos += len;
1912 return 0;
1916 * proc_dostring - read a string sysctl
1917 * @table: the sysctl table
1918 * @write: %TRUE if this is a write to the sysctl file
1919 * @filp: the file structure
1920 * @buffer: the user buffer
1921 * @lenp: the size of the user buffer
1922 * @ppos: file position
1924 * Reads/writes a string from/to the user buffer. If the kernel
1925 * buffer provided is not large enough to hold the string, the
1926 * string is truncated. The copied string is %NULL-terminated.
1927 * If the string is being read by the user process, it is copied
1928 * and a newline '\n' is added. It is truncated if the buffer is
1929 * not large enough.
1931 * Returns 0 on success.
1933 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
1934 void __user *buffer, size_t *lenp, loff_t *ppos)
1936 return _proc_do_string(table->data, table->maxlen, write, filp,
1937 buffer, lenp, ppos);
1941 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1942 int *valp,
1943 int write, void *data)
1945 if (write) {
1946 *valp = *negp ? -*lvalp : *lvalp;
1947 } else {
1948 int val = *valp;
1949 if (val < 0) {
1950 *negp = -1;
1951 *lvalp = (unsigned long)-val;
1952 } else {
1953 *negp = 0;
1954 *lvalp = (unsigned long)val;
1957 return 0;
1960 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
1961 int write, struct file *filp, void __user *buffer,
1962 size_t *lenp, loff_t *ppos,
1963 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1964 int write, void *data),
1965 void *data)
1967 #define TMPBUFLEN 21
1968 int *i, vleft, first=1, neg, val;
1969 unsigned long lval;
1970 size_t left, len;
1972 char buf[TMPBUFLEN], *p;
1973 char __user *s = buffer;
1975 if (!tbl_data || !table->maxlen || !*lenp ||
1976 (*ppos && !write)) {
1977 *lenp = 0;
1978 return 0;
1981 i = (int *) tbl_data;
1982 vleft = table->maxlen / sizeof(*i);
1983 left = *lenp;
1985 if (!conv)
1986 conv = do_proc_dointvec_conv;
1988 for (; left && vleft--; i++, first=0) {
1989 if (write) {
1990 while (left) {
1991 char c;
1992 if (get_user(c, s))
1993 return -EFAULT;
1994 if (!isspace(c))
1995 break;
1996 left--;
1997 s++;
1999 if (!left)
2000 break;
2001 neg = 0;
2002 len = left;
2003 if (len > sizeof(buf) - 1)
2004 len = sizeof(buf) - 1;
2005 if (copy_from_user(buf, s, len))
2006 return -EFAULT;
2007 buf[len] = 0;
2008 p = buf;
2009 if (*p == '-' && left > 1) {
2010 neg = 1;
2011 p++;
2013 if (*p < '0' || *p > '9')
2014 break;
2016 lval = simple_strtoul(p, &p, 0);
2018 len = p-buf;
2019 if ((len < left) && *p && !isspace(*p))
2020 break;
2021 if (neg)
2022 val = -val;
2023 s += len;
2024 left -= len;
2026 if (conv(&neg, &lval, i, 1, data))
2027 break;
2028 } else {
2029 p = buf;
2030 if (!first)
2031 *p++ = '\t';
2033 if (conv(&neg, &lval, i, 0, data))
2034 break;
2036 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2037 len = strlen(buf);
2038 if (len > left)
2039 len = left;
2040 if(copy_to_user(s, buf, len))
2041 return -EFAULT;
2042 left -= len;
2043 s += len;
2047 if (!write && !first && left) {
2048 if(put_user('\n', s))
2049 return -EFAULT;
2050 left--, s++;
2052 if (write) {
2053 while (left) {
2054 char c;
2055 if (get_user(c, s++))
2056 return -EFAULT;
2057 if (!isspace(c))
2058 break;
2059 left--;
2062 if (write && first)
2063 return -EINVAL;
2064 *lenp -= left;
2065 *ppos += *lenp;
2066 return 0;
2067 #undef TMPBUFLEN
2070 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2071 void __user *buffer, size_t *lenp, loff_t *ppos,
2072 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2073 int write, void *data),
2074 void *data)
2076 return __do_proc_dointvec(table->data, table, write, filp,
2077 buffer, lenp, ppos, conv, data);
2081 * proc_dointvec - read a vector of integers
2082 * @table: the sysctl table
2083 * @write: %TRUE if this is a write to the sysctl file
2084 * @filp: the file structure
2085 * @buffer: the user buffer
2086 * @lenp: the size of the user buffer
2087 * @ppos: file position
2089 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2090 * values from/to the user buffer, treated as an ASCII string.
2092 * Returns 0 on success.
2094 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2095 void __user *buffer, size_t *lenp, loff_t *ppos)
2097 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2098 NULL,NULL);
2101 #define OP_SET 0
2102 #define OP_AND 1
2103 #define OP_OR 2
2105 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
2106 int *valp,
2107 int write, void *data)
2109 int op = *(int *)data;
2110 if (write) {
2111 int val = *negp ? -*lvalp : *lvalp;
2112 switch(op) {
2113 case OP_SET: *valp = val; break;
2114 case OP_AND: *valp &= val; break;
2115 case OP_OR: *valp |= val; break;
2117 } else {
2118 int val = *valp;
2119 if (val < 0) {
2120 *negp = -1;
2121 *lvalp = (unsigned long)-val;
2122 } else {
2123 *negp = 0;
2124 *lvalp = (unsigned long)val;
2127 return 0;
2131 * Taint values can only be increased
2133 static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
2134 void __user *buffer, size_t *lenp, loff_t *ppos)
2136 int op;
2138 if (write && !capable(CAP_SYS_ADMIN))
2139 return -EPERM;
2141 op = OP_OR;
2142 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2143 do_proc_dointvec_bset_conv,&op);
2146 struct do_proc_dointvec_minmax_conv_param {
2147 int *min;
2148 int *max;
2151 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2152 int *valp,
2153 int write, void *data)
2155 struct do_proc_dointvec_minmax_conv_param *param = data;
2156 if (write) {
2157 int val = *negp ? -*lvalp : *lvalp;
2158 if ((param->min && *param->min > val) ||
2159 (param->max && *param->max < val))
2160 return -EINVAL;
2161 *valp = val;
2162 } else {
2163 int val = *valp;
2164 if (val < 0) {
2165 *negp = -1;
2166 *lvalp = (unsigned long)-val;
2167 } else {
2168 *negp = 0;
2169 *lvalp = (unsigned long)val;
2172 return 0;
2176 * proc_dointvec_minmax - read a vector of integers with min/max values
2177 * @table: the sysctl table
2178 * @write: %TRUE if this is a write to the sysctl file
2179 * @filp: the file structure
2180 * @buffer: the user buffer
2181 * @lenp: the size of the user buffer
2182 * @ppos: file position
2184 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2185 * values from/to the user buffer, treated as an ASCII string.
2187 * This routine will ensure the values are within the range specified by
2188 * table->extra1 (min) and table->extra2 (max).
2190 * Returns 0 on success.
2192 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2193 void __user *buffer, size_t *lenp, loff_t *ppos)
2195 struct do_proc_dointvec_minmax_conv_param param = {
2196 .min = (int *) table->extra1,
2197 .max = (int *) table->extra2,
2199 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2200 do_proc_dointvec_minmax_conv, &param);
2203 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2204 struct file *filp,
2205 void __user *buffer,
2206 size_t *lenp, loff_t *ppos,
2207 unsigned long convmul,
2208 unsigned long convdiv)
2210 #define TMPBUFLEN 21
2211 unsigned long *i, *min, *max, val;
2212 int vleft, first=1, neg;
2213 size_t len, left;
2214 char buf[TMPBUFLEN], *p;
2215 char __user *s = buffer;
2217 if (!data || !table->maxlen || !*lenp ||
2218 (*ppos && !write)) {
2219 *lenp = 0;
2220 return 0;
2223 i = (unsigned long *) data;
2224 min = (unsigned long *) table->extra1;
2225 max = (unsigned long *) table->extra2;
2226 vleft = table->maxlen / sizeof(unsigned long);
2227 left = *lenp;
2229 for (; left && vleft--; i++, min++, max++, first=0) {
2230 if (write) {
2231 while (left) {
2232 char c;
2233 if (get_user(c, s))
2234 return -EFAULT;
2235 if (!isspace(c))
2236 break;
2237 left--;
2238 s++;
2240 if (!left)
2241 break;
2242 neg = 0;
2243 len = left;
2244 if (len > TMPBUFLEN-1)
2245 len = TMPBUFLEN-1;
2246 if (copy_from_user(buf, s, len))
2247 return -EFAULT;
2248 buf[len] = 0;
2249 p = buf;
2250 if (*p == '-' && left > 1) {
2251 neg = 1;
2252 p++;
2254 if (*p < '0' || *p > '9')
2255 break;
2256 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2257 len = p-buf;
2258 if ((len < left) && *p && !isspace(*p))
2259 break;
2260 if (neg)
2261 val = -val;
2262 s += len;
2263 left -= len;
2265 if(neg)
2266 continue;
2267 if ((min && val < *min) || (max && val > *max))
2268 continue;
2269 *i = val;
2270 } else {
2271 p = buf;
2272 if (!first)
2273 *p++ = '\t';
2274 sprintf(p, "%lu", convdiv * (*i) / convmul);
2275 len = strlen(buf);
2276 if (len > left)
2277 len = left;
2278 if(copy_to_user(s, buf, len))
2279 return -EFAULT;
2280 left -= len;
2281 s += len;
2285 if (!write && !first && left) {
2286 if(put_user('\n', s))
2287 return -EFAULT;
2288 left--, s++;
2290 if (write) {
2291 while (left) {
2292 char c;
2293 if (get_user(c, s++))
2294 return -EFAULT;
2295 if (!isspace(c))
2296 break;
2297 left--;
2300 if (write && first)
2301 return -EINVAL;
2302 *lenp -= left;
2303 *ppos += *lenp;
2304 return 0;
2305 #undef TMPBUFLEN
2308 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2309 struct file *filp,
2310 void __user *buffer,
2311 size_t *lenp, loff_t *ppos,
2312 unsigned long convmul,
2313 unsigned long convdiv)
2315 return __do_proc_doulongvec_minmax(table->data, table, write,
2316 filp, buffer, lenp, ppos, convmul, convdiv);
2320 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2321 * @table: the sysctl table
2322 * @write: %TRUE if this is a write to the sysctl file
2323 * @filp: the file structure
2324 * @buffer: the user buffer
2325 * @lenp: the size of the user buffer
2326 * @ppos: file position
2328 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2329 * values from/to the user buffer, treated as an ASCII string.
2331 * This routine will ensure the values are within the range specified by
2332 * table->extra1 (min) and table->extra2 (max).
2334 * Returns 0 on success.
2336 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2337 void __user *buffer, size_t *lenp, loff_t *ppos)
2339 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2343 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2344 * @table: the sysctl table
2345 * @write: %TRUE if this is a write to the sysctl file
2346 * @filp: the file structure
2347 * @buffer: the user buffer
2348 * @lenp: the size of the user buffer
2349 * @ppos: file position
2351 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2352 * values from/to the user buffer, treated as an ASCII string. The values
2353 * are treated as milliseconds, and converted to jiffies when they are stored.
2355 * This routine will ensure the values are within the range specified by
2356 * table->extra1 (min) and table->extra2 (max).
2358 * Returns 0 on success.
2360 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2361 struct file *filp,
2362 void __user *buffer,
2363 size_t *lenp, loff_t *ppos)
2365 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2366 lenp, ppos, HZ, 1000l);
2370 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2371 int *valp,
2372 int write, void *data)
2374 if (write) {
2375 if (*lvalp > LONG_MAX / HZ)
2376 return 1;
2377 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2378 } else {
2379 int val = *valp;
2380 unsigned long lval;
2381 if (val < 0) {
2382 *negp = -1;
2383 lval = (unsigned long)-val;
2384 } else {
2385 *negp = 0;
2386 lval = (unsigned long)val;
2388 *lvalp = lval / HZ;
2390 return 0;
2393 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2394 int *valp,
2395 int write, void *data)
2397 if (write) {
2398 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2399 return 1;
2400 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2401 } else {
2402 int val = *valp;
2403 unsigned long lval;
2404 if (val < 0) {
2405 *negp = -1;
2406 lval = (unsigned long)-val;
2407 } else {
2408 *negp = 0;
2409 lval = (unsigned long)val;
2411 *lvalp = jiffies_to_clock_t(lval);
2413 return 0;
2416 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2417 int *valp,
2418 int write, void *data)
2420 if (write) {
2421 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2422 } else {
2423 int val = *valp;
2424 unsigned long lval;
2425 if (val < 0) {
2426 *negp = -1;
2427 lval = (unsigned long)-val;
2428 } else {
2429 *negp = 0;
2430 lval = (unsigned long)val;
2432 *lvalp = jiffies_to_msecs(lval);
2434 return 0;
2438 * proc_dointvec_jiffies - read a vector of integers as seconds
2439 * @table: the sysctl table
2440 * @write: %TRUE if this is a write to the sysctl file
2441 * @filp: the file structure
2442 * @buffer: the user buffer
2443 * @lenp: the size of the user buffer
2444 * @ppos: file position
2446 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2447 * values from/to the user buffer, treated as an ASCII string.
2448 * The values read are assumed to be in seconds, and are converted into
2449 * jiffies.
2451 * Returns 0 on success.
2453 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2454 void __user *buffer, size_t *lenp, loff_t *ppos)
2456 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2457 do_proc_dointvec_jiffies_conv,NULL);
2461 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2462 * @table: the sysctl table
2463 * @write: %TRUE if this is a write to the sysctl file
2464 * @filp: the file structure
2465 * @buffer: the user buffer
2466 * @lenp: the size of the user buffer
2467 * @ppos: pointer to the file position
2469 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2470 * values from/to the user buffer, treated as an ASCII string.
2471 * The values read are assumed to be in 1/USER_HZ seconds, and
2472 * are converted into jiffies.
2474 * Returns 0 on success.
2476 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2477 void __user *buffer, size_t *lenp, loff_t *ppos)
2479 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2480 do_proc_dointvec_userhz_jiffies_conv,NULL);
2484 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2485 * @table: the sysctl table
2486 * @write: %TRUE if this is a write to the sysctl file
2487 * @filp: the file structure
2488 * @buffer: the user buffer
2489 * @lenp: the size of the user buffer
2490 * @ppos: file position
2491 * @ppos: the current position in the file
2493 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2494 * values from/to the user buffer, treated as an ASCII string.
2495 * The values read are assumed to be in 1/1000 seconds, and
2496 * are converted into jiffies.
2498 * Returns 0 on success.
2500 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2501 void __user *buffer, size_t *lenp, loff_t *ppos)
2503 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2504 do_proc_dointvec_ms_jiffies_conv, NULL);
2507 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2508 void __user *buffer, size_t *lenp, loff_t *ppos)
2510 struct pid *new_pid;
2511 pid_t tmp;
2512 int r;
2514 tmp = pid_vnr(cad_pid);
2516 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2517 lenp, ppos, NULL, NULL);
2518 if (r || !write)
2519 return r;
2521 new_pid = find_get_pid(tmp);
2522 if (!new_pid)
2523 return -ESRCH;
2525 put_pid(xchg(&cad_pid, new_pid));
2526 return 0;
2529 #else /* CONFIG_PROC_FS */
2531 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2532 void __user *buffer, size_t *lenp, loff_t *ppos)
2534 return -ENOSYS;
2537 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2538 void __user *buffer, size_t *lenp, loff_t *ppos)
2540 return -ENOSYS;
2543 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2544 void __user *buffer, size_t *lenp, loff_t *ppos)
2546 return -ENOSYS;
2549 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2550 void __user *buffer, size_t *lenp, loff_t *ppos)
2552 return -ENOSYS;
2555 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2556 void __user *buffer, size_t *lenp, loff_t *ppos)
2558 return -ENOSYS;
2561 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2562 void __user *buffer, size_t *lenp, loff_t *ppos)
2564 return -ENOSYS;
2567 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2568 void __user *buffer, size_t *lenp, loff_t *ppos)
2570 return -ENOSYS;
2573 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2574 struct file *filp,
2575 void __user *buffer,
2576 size_t *lenp, loff_t *ppos)
2578 return -ENOSYS;
2582 #endif /* CONFIG_PROC_FS */
2585 #ifdef CONFIG_SYSCTL_SYSCALL
2587 * General sysctl support routines
2590 /* The generic sysctl data routine (used if no strategy routine supplied) */
2591 int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2592 void __user *oldval, size_t __user *oldlenp,
2593 void __user *newval, size_t newlen)
2595 size_t len;
2597 /* Get out of I don't have a variable */
2598 if (!table->data || !table->maxlen)
2599 return -ENOTDIR;
2601 if (oldval && oldlenp) {
2602 if (get_user(len, oldlenp))
2603 return -EFAULT;
2604 if (len) {
2605 if (len > table->maxlen)
2606 len = table->maxlen;
2607 if (copy_to_user(oldval, table->data, len))
2608 return -EFAULT;
2609 if (put_user(len, oldlenp))
2610 return -EFAULT;
2614 if (newval && newlen) {
2615 if (newlen > table->maxlen)
2616 newlen = table->maxlen;
2618 if (copy_from_user(table->data, newval, newlen))
2619 return -EFAULT;
2621 return 1;
2624 /* The generic string strategy routine: */
2625 int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2626 void __user *oldval, size_t __user *oldlenp,
2627 void __user *newval, size_t newlen)
2629 if (!table->data || !table->maxlen)
2630 return -ENOTDIR;
2632 if (oldval && oldlenp) {
2633 size_t bufsize;
2634 if (get_user(bufsize, oldlenp))
2635 return -EFAULT;
2636 if (bufsize) {
2637 size_t len = strlen(table->data), copied;
2639 /* This shouldn't trigger for a well-formed sysctl */
2640 if (len > table->maxlen)
2641 len = table->maxlen;
2643 /* Copy up to a max of bufsize-1 bytes of the string */
2644 copied = (len >= bufsize) ? bufsize - 1 : len;
2646 if (copy_to_user(oldval, table->data, copied) ||
2647 put_user(0, (char __user *)(oldval + copied)))
2648 return -EFAULT;
2649 if (put_user(len, oldlenp))
2650 return -EFAULT;
2653 if (newval && newlen) {
2654 size_t len = newlen;
2655 if (len > table->maxlen)
2656 len = table->maxlen;
2657 if(copy_from_user(table->data, newval, len))
2658 return -EFAULT;
2659 if (len == table->maxlen)
2660 len--;
2661 ((char *) table->data)[len] = 0;
2663 return 1;
2667 * This function makes sure that all of the integers in the vector
2668 * are between the minimum and maximum values given in the arrays
2669 * table->extra1 and table->extra2, respectively.
2671 int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2672 void __user *oldval, size_t __user *oldlenp,
2673 void __user *newval, size_t newlen)
2676 if (newval && newlen) {
2677 int __user *vec = (int __user *) newval;
2678 int *min = (int *) table->extra1;
2679 int *max = (int *) table->extra2;
2680 size_t length;
2681 int i;
2683 if (newlen % sizeof(int) != 0)
2684 return -EINVAL;
2686 if (!table->extra1 && !table->extra2)
2687 return 0;
2689 if (newlen > table->maxlen)
2690 newlen = table->maxlen;
2691 length = newlen / sizeof(int);
2693 for (i = 0; i < length; i++) {
2694 int value;
2695 if (get_user(value, vec + i))
2696 return -EFAULT;
2697 if (min && value < min[i])
2698 return -EINVAL;
2699 if (max && value > max[i])
2700 return -EINVAL;
2703 return 0;
2706 /* Strategy function to convert jiffies to seconds */
2707 int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2708 void __user *oldval, size_t __user *oldlenp,
2709 void __user *newval, size_t newlen)
2711 if (oldval && oldlenp) {
2712 size_t olen;
2714 if (get_user(olen, oldlenp))
2715 return -EFAULT;
2716 if (olen) {
2717 int val;
2719 if (olen < sizeof(int))
2720 return -EINVAL;
2722 val = *(int *)(table->data) / HZ;
2723 if (put_user(val, (int __user *)oldval))
2724 return -EFAULT;
2725 if (put_user(sizeof(int), oldlenp))
2726 return -EFAULT;
2729 if (newval && newlen) {
2730 int new;
2731 if (newlen != sizeof(int))
2732 return -EINVAL;
2733 if (get_user(new, (int __user *)newval))
2734 return -EFAULT;
2735 *(int *)(table->data) = new*HZ;
2737 return 1;
2740 /* Strategy function to convert jiffies to seconds */
2741 int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2742 void __user *oldval, size_t __user *oldlenp,
2743 void __user *newval, size_t newlen)
2745 if (oldval && oldlenp) {
2746 size_t olen;
2748 if (get_user(olen, oldlenp))
2749 return -EFAULT;
2750 if (olen) {
2751 int val;
2753 if (olen < sizeof(int))
2754 return -EINVAL;
2756 val = jiffies_to_msecs(*(int *)(table->data));
2757 if (put_user(val, (int __user *)oldval))
2758 return -EFAULT;
2759 if (put_user(sizeof(int), oldlenp))
2760 return -EFAULT;
2763 if (newval && newlen) {
2764 int new;
2765 if (newlen != sizeof(int))
2766 return -EINVAL;
2767 if (get_user(new, (int __user *)newval))
2768 return -EFAULT;
2769 *(int *)(table->data) = msecs_to_jiffies(new);
2771 return 1;
2776 #else /* CONFIG_SYSCTL_SYSCALL */
2779 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2781 struct __sysctl_args tmp;
2782 int error;
2784 if (copy_from_user(&tmp, args, sizeof(tmp)))
2785 return -EFAULT;
2787 error = deprecated_sysctl_warning(&tmp);
2789 /* If no error reading the parameters then just -ENOSYS ... */
2790 if (!error)
2791 error = -ENOSYS;
2793 return error;
2796 int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2797 void __user *oldval, size_t __user *oldlenp,
2798 void __user *newval, size_t newlen)
2800 return -ENOSYS;
2803 int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2804 void __user *oldval, size_t __user *oldlenp,
2805 void __user *newval, size_t newlen)
2807 return -ENOSYS;
2810 int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2811 void __user *oldval, size_t __user *oldlenp,
2812 void __user *newval, size_t newlen)
2814 return -ENOSYS;
2817 int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2818 void __user *oldval, size_t __user *oldlenp,
2819 void __user *newval, size_t newlen)
2821 return -ENOSYS;
2824 int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2825 void __user *oldval, size_t __user *oldlenp,
2826 void __user *newval, size_t newlen)
2828 return -ENOSYS;
2831 #endif /* CONFIG_SYSCTL_SYSCALL */
2833 static int deprecated_sysctl_warning(struct __sysctl_args *args)
2835 static int msg_count;
2836 int name[CTL_MAXNAME];
2837 int i;
2839 /* Check args->nlen. */
2840 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
2841 return -ENOTDIR;
2843 /* Read in the sysctl name for better debug message logging */
2844 for (i = 0; i < args->nlen; i++)
2845 if (get_user(name[i], args->name + i))
2846 return -EFAULT;
2848 /* Ignore accesses to kernel.version */
2849 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2850 return 0;
2852 if (msg_count < 5) {
2853 msg_count++;
2854 printk(KERN_INFO
2855 "warning: process `%s' used the deprecated sysctl "
2856 "system call with ", current->comm);
2857 for (i = 0; i < args->nlen; i++)
2858 printk("%d.", name[i]);
2859 printk("\n");
2861 return 0;
2865 * No sense putting this after each symbol definition, twice,
2866 * exception granted :-)
2868 EXPORT_SYMBOL(proc_dointvec);
2869 EXPORT_SYMBOL(proc_dointvec_jiffies);
2870 EXPORT_SYMBOL(proc_dointvec_minmax);
2871 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2872 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2873 EXPORT_SYMBOL(proc_dostring);
2874 EXPORT_SYMBOL(proc_doulongvec_minmax);
2875 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2876 EXPORT_SYMBOL(register_sysctl_table);
2877 EXPORT_SYMBOL(register_sysctl_paths);
2878 EXPORT_SYMBOL(sysctl_intvec);
2879 EXPORT_SYMBOL(sysctl_jiffies);
2880 EXPORT_SYMBOL(sysctl_ms_jiffies);
2881 EXPORT_SYMBOL(sysctl_string);
2882 EXPORT_SYMBOL(sysctl_data);
2883 EXPORT_SYMBOL(unregister_sysctl_table);