xHCI: fix wMaxPacketSize mask
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / sysctl.c
blobc33a1edb799fda6db2e16fdf9d1d0401a9f78278
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/signal.h>
27 #include <linux/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/ctype.h>
30 #include <linux/kmemcheck.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/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/dnotify.h>
48 #include <linux/syscalls.h>
49 #include <linux/vmstat.h>
50 #include <linux/nfs_fs.h>
51 #include <linux/acpi.h>
52 #include <linux/reboot.h>
53 #include <linux/ftrace.h>
54 #include <linux/perf_event.h>
55 #include <linux/kprobes.h>
56 #include <linux/pipe_fs_i.h>
57 #include <linux/oom.h>
59 #include <asm/uaccess.h>
60 #include <asm/processor.h>
62 #ifdef CONFIG_X86
63 #include <asm/nmi.h>
64 #include <asm/stacktrace.h>
65 #include <asm/io.h>
66 #endif
67 #ifdef CONFIG_BSD_PROCESS_ACCT
68 #include <linux/acct.h>
69 #endif
70 #ifdef CONFIG_RT_MUTEXES
71 #include <linux/rtmutex.h>
72 #endif
73 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
74 #include <linux/lockdep.h>
75 #endif
76 #ifdef CONFIG_CHR_DEV_SG
77 #include <scsi/sg.h>
78 #endif
80 #ifdef CONFIG_LOCKUP_DETECTOR
81 #include <linux/nmi.h>
82 #endif
85 #if defined(CONFIG_SYSCTL)
87 /* External variables not in a header file. */
88 extern int sysctl_overcommit_memory;
89 extern int sysctl_overcommit_ratio;
90 extern int max_threads;
91 extern int core_uses_pid;
92 extern int suid_dumpable;
93 extern char core_pattern[];
94 extern unsigned int core_pipe_limit;
95 extern int pid_max;
96 extern int min_free_kbytes;
97 extern int pid_max_min, pid_max_max;
98 extern int sysctl_drop_caches;
99 extern int percpu_pagelist_fraction;
100 extern int compat_log;
101 extern int latencytop_enabled;
102 extern int sysctl_nr_open_min, sysctl_nr_open_max;
103 #ifndef CONFIG_MMU
104 extern int sysctl_nr_trim_pages;
105 #endif
106 #ifdef CONFIG_BLOCK
107 extern int blk_iopoll_enabled;
108 #endif
110 /* Constants used for minimum and maximum */
111 #ifdef CONFIG_LOCKUP_DETECTOR
112 static int sixty = 60;
113 static int neg_one = -1;
114 #endif
116 static int zero;
117 static int __maybe_unused one = 1;
118 static int __maybe_unused two = 2;
119 static unsigned long one_ul = 1;
120 static int one_hundred = 100;
121 #ifdef CONFIG_PRINTK
122 static int ten_thousand = 10000;
123 #endif
125 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
126 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
128 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
129 static int maxolduid = 65535;
130 static int minolduid;
131 static int min_percpu_pagelist_fract = 8;
133 static int ngroups_max = NGROUPS_MAX;
135 #ifdef CONFIG_INOTIFY_USER
136 #include <linux/inotify.h>
137 #endif
138 #ifdef CONFIG_SPARC
139 #include <asm/system.h>
140 #endif
142 #ifdef CONFIG_SPARC64
143 extern int sysctl_tsb_ratio;
144 #endif
146 #ifdef __hppa__
147 extern int pwrsw_enabled;
148 extern int unaligned_enabled;
149 #endif
151 #ifdef CONFIG_S390
152 #ifdef CONFIG_MATHEMU
153 extern int sysctl_ieee_emulation_warnings;
154 #endif
155 extern int sysctl_userprocess_debug;
156 extern int spin_retry;
157 #endif
159 #ifdef CONFIG_IA64
160 extern int no_unaligned_warning;
161 extern int unaligned_dump_stack;
162 #endif
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);
169 #endif
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,
176 loff_t *ppos)
178 int error;
180 error = proc_dointvec(table, write, buffer, lenp, ppos);
181 if (error)
182 return error;
184 if (write)
185 sysrq_toggle_support(__sysrq_enabled);
187 return 0;
190 #endif
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 = {
195 .count = 1,
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_EPOLL
213 extern struct ctl_table epoll_table[];
214 #endif
216 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
217 int sysctl_legacy_va_layout;
218 #endif
220 /* The default sysctl tables: */
222 static struct ctl_table root_table[] = {
224 .procname = "kernel",
225 .mode = 0555,
226 .child = kern_table,
229 .procname = "vm",
230 .mode = 0555,
231 .child = vm_table,
234 .procname = "fs",
235 .mode = 0555,
236 .child = fs_table,
239 .procname = "debug",
240 .mode = 0555,
241 .child = debug_table,
244 .procname = "dev",
245 .mode = 0555,
246 .child = dev_table,
249 * NOTE: do not add new entries to this table unless you have read
250 * Documentation/sysctl/ctl_unnumbered.txt
255 #ifdef CONFIG_SCHED_DEBUG
256 static int min_sched_granularity_ns = 100000; /* 100 usecs */
257 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
258 static int min_wakeup_granularity_ns; /* 0 usecs */
259 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
260 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
261 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
262 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
263 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
264 #endif
266 #ifdef CONFIG_COMPACTION
267 static int min_extfrag_threshold;
268 static int max_extfrag_threshold = 1000;
269 #endif
271 static struct ctl_table kern_table[] = {
273 .procname = "sched_child_runs_first",
274 .data = &sysctl_sched_child_runs_first,
275 .maxlen = sizeof(unsigned int),
276 .mode = 0644,
277 .proc_handler = proc_dointvec,
279 #ifdef CONFIG_SCHED_DEBUG
281 .procname = "sched_min_granularity_ns",
282 .data = &sysctl_sched_min_granularity,
283 .maxlen = sizeof(unsigned int),
284 .mode = 0644,
285 .proc_handler = sched_proc_update_handler,
286 .extra1 = &min_sched_granularity_ns,
287 .extra2 = &max_sched_granularity_ns,
290 .procname = "sched_latency_ns",
291 .data = &sysctl_sched_latency,
292 .maxlen = sizeof(unsigned int),
293 .mode = 0644,
294 .proc_handler = sched_proc_update_handler,
295 .extra1 = &min_sched_granularity_ns,
296 .extra2 = &max_sched_granularity_ns,
299 .procname = "sched_wakeup_granularity_ns",
300 .data = &sysctl_sched_wakeup_granularity,
301 .maxlen = sizeof(unsigned int),
302 .mode = 0644,
303 .proc_handler = sched_proc_update_handler,
304 .extra1 = &min_wakeup_granularity_ns,
305 .extra2 = &max_wakeup_granularity_ns,
308 .procname = "sched_shares_ratelimit",
309 .data = &sysctl_sched_shares_ratelimit,
310 .maxlen = sizeof(unsigned int),
311 .mode = 0644,
312 .proc_handler = sched_proc_update_handler,
313 .extra1 = &min_sched_shares_ratelimit,
314 .extra2 = &max_sched_shares_ratelimit,
317 .procname = "sched_tunable_scaling",
318 .data = &sysctl_sched_tunable_scaling,
319 .maxlen = sizeof(enum sched_tunable_scaling),
320 .mode = 0644,
321 .proc_handler = sched_proc_update_handler,
322 .extra1 = &min_sched_tunable_scaling,
323 .extra2 = &max_sched_tunable_scaling,
326 .procname = "sched_shares_thresh",
327 .data = &sysctl_sched_shares_thresh,
328 .maxlen = sizeof(unsigned int),
329 .mode = 0644,
330 .proc_handler = proc_dointvec_minmax,
331 .extra1 = &zero,
334 .procname = "sched_migration_cost",
335 .data = &sysctl_sched_migration_cost,
336 .maxlen = sizeof(unsigned int),
337 .mode = 0644,
338 .proc_handler = proc_dointvec,
341 .procname = "sched_nr_migrate",
342 .data = &sysctl_sched_nr_migrate,
343 .maxlen = sizeof(unsigned int),
344 .mode = 0644,
345 .proc_handler = proc_dointvec,
348 .procname = "sched_time_avg",
349 .data = &sysctl_sched_time_avg,
350 .maxlen = sizeof(unsigned int),
351 .mode = 0644,
352 .proc_handler = proc_dointvec,
355 .procname = "timer_migration",
356 .data = &sysctl_timer_migration,
357 .maxlen = sizeof(unsigned int),
358 .mode = 0644,
359 .proc_handler = proc_dointvec_minmax,
360 .extra1 = &zero,
361 .extra2 = &one,
363 #endif
365 .procname = "sched_rt_period_us",
366 .data = &sysctl_sched_rt_period,
367 .maxlen = sizeof(unsigned int),
368 .mode = 0644,
369 .proc_handler = sched_rt_handler,
372 .procname = "sched_rt_runtime_us",
373 .data = &sysctl_sched_rt_runtime,
374 .maxlen = sizeof(int),
375 .mode = 0644,
376 .proc_handler = sched_rt_handler,
379 .procname = "sched_compat_yield",
380 .data = &sysctl_sched_compat_yield,
381 .maxlen = sizeof(unsigned int),
382 .mode = 0644,
383 .proc_handler = proc_dointvec,
385 #ifdef CONFIG_PROVE_LOCKING
387 .procname = "prove_locking",
388 .data = &prove_locking,
389 .maxlen = sizeof(int),
390 .mode = 0644,
391 .proc_handler = proc_dointvec,
393 #endif
394 #ifdef CONFIG_LOCK_STAT
396 .procname = "lock_stat",
397 .data = &lock_stat,
398 .maxlen = sizeof(int),
399 .mode = 0644,
400 .proc_handler = proc_dointvec,
402 #endif
404 .procname = "panic",
405 .data = &panic_timeout,
406 .maxlen = sizeof(int),
407 .mode = 0644,
408 .proc_handler = proc_dointvec,
411 .procname = "core_uses_pid",
412 .data = &core_uses_pid,
413 .maxlen = sizeof(int),
414 .mode = 0644,
415 .proc_handler = proc_dointvec,
418 .procname = "core_pattern",
419 .data = core_pattern,
420 .maxlen = CORENAME_MAX_SIZE,
421 .mode = 0644,
422 .proc_handler = proc_dostring,
425 .procname = "core_pipe_limit",
426 .data = &core_pipe_limit,
427 .maxlen = sizeof(unsigned int),
428 .mode = 0644,
429 .proc_handler = proc_dointvec,
431 #ifdef CONFIG_PROC_SYSCTL
433 .procname = "tainted",
434 .maxlen = sizeof(long),
435 .mode = 0644,
436 .proc_handler = proc_taint,
438 #endif
439 #ifdef CONFIG_LATENCYTOP
441 .procname = "latencytop",
442 .data = &latencytop_enabled,
443 .maxlen = sizeof(int),
444 .mode = 0644,
445 .proc_handler = proc_dointvec,
447 #endif
448 #ifdef CONFIG_BLK_DEV_INITRD
450 .procname = "real-root-dev",
451 .data = &real_root_dev,
452 .maxlen = sizeof(int),
453 .mode = 0644,
454 .proc_handler = proc_dointvec,
456 #endif
458 .procname = "print-fatal-signals",
459 .data = &print_fatal_signals,
460 .maxlen = sizeof(int),
461 .mode = 0644,
462 .proc_handler = proc_dointvec,
464 #ifdef CONFIG_SPARC
466 .procname = "reboot-cmd",
467 .data = reboot_command,
468 .maxlen = 256,
469 .mode = 0644,
470 .proc_handler = proc_dostring,
473 .procname = "stop-a",
474 .data = &stop_a_enabled,
475 .maxlen = sizeof (int),
476 .mode = 0644,
477 .proc_handler = proc_dointvec,
480 .procname = "scons-poweroff",
481 .data = &scons_pwroff,
482 .maxlen = sizeof (int),
483 .mode = 0644,
484 .proc_handler = proc_dointvec,
486 #endif
487 #ifdef CONFIG_SPARC64
489 .procname = "tsb-ratio",
490 .data = &sysctl_tsb_ratio,
491 .maxlen = sizeof (int),
492 .mode = 0644,
493 .proc_handler = proc_dointvec,
495 #endif
496 #ifdef __hppa__
498 .procname = "soft-power",
499 .data = &pwrsw_enabled,
500 .maxlen = sizeof (int),
501 .mode = 0644,
502 .proc_handler = proc_dointvec,
505 .procname = "unaligned-trap",
506 .data = &unaligned_enabled,
507 .maxlen = sizeof (int),
508 .mode = 0644,
509 .proc_handler = proc_dointvec,
511 #endif
513 .procname = "ctrl-alt-del",
514 .data = &C_A_D,
515 .maxlen = sizeof(int),
516 .mode = 0644,
517 .proc_handler = proc_dointvec,
519 #ifdef CONFIG_FUNCTION_TRACER
521 .procname = "ftrace_enabled",
522 .data = &ftrace_enabled,
523 .maxlen = sizeof(int),
524 .mode = 0644,
525 .proc_handler = ftrace_enable_sysctl,
527 #endif
528 #ifdef CONFIG_STACK_TRACER
530 .procname = "stack_tracer_enabled",
531 .data = &stack_tracer_enabled,
532 .maxlen = sizeof(int),
533 .mode = 0644,
534 .proc_handler = stack_trace_sysctl,
536 #endif
537 #ifdef CONFIG_TRACING
539 .procname = "ftrace_dump_on_oops",
540 .data = &ftrace_dump_on_oops,
541 .maxlen = sizeof(int),
542 .mode = 0644,
543 .proc_handler = proc_dointvec,
545 #endif
546 #ifdef CONFIG_MODULES
548 .procname = "modprobe",
549 .data = &modprobe_path,
550 .maxlen = KMOD_PATH_LEN,
551 .mode = 0644,
552 .proc_handler = proc_dostring,
555 .procname = "modules_disabled",
556 .data = &modules_disabled,
557 .maxlen = sizeof(int),
558 .mode = 0644,
559 /* only handle a transition from default "0" to "1" */
560 .proc_handler = proc_dointvec_minmax,
561 .extra1 = &one,
562 .extra2 = &one,
564 #endif
565 #ifdef CONFIG_HOTPLUG
567 .procname = "hotplug",
568 .data = &uevent_helper,
569 .maxlen = UEVENT_HELPER_PATH_LEN,
570 .mode = 0644,
571 .proc_handler = proc_dostring,
573 #endif
574 #ifdef CONFIG_CHR_DEV_SG
576 .procname = "sg-big-buff",
577 .data = &sg_big_buff,
578 .maxlen = sizeof (int),
579 .mode = 0444,
580 .proc_handler = proc_dointvec,
582 #endif
583 #ifdef CONFIG_BSD_PROCESS_ACCT
585 .procname = "acct",
586 .data = &acct_parm,
587 .maxlen = 3*sizeof(int),
588 .mode = 0644,
589 .proc_handler = proc_dointvec,
591 #endif
592 #ifdef CONFIG_MAGIC_SYSRQ
594 .procname = "sysrq",
595 .data = &__sysrq_enabled,
596 .maxlen = sizeof (int),
597 .mode = 0644,
598 .proc_handler = sysrq_sysctl_handler,
600 #endif
601 #ifdef CONFIG_PROC_SYSCTL
603 .procname = "cad_pid",
604 .data = NULL,
605 .maxlen = sizeof (int),
606 .mode = 0600,
607 .proc_handler = proc_do_cad_pid,
609 #endif
611 .procname = "threads-max",
612 .data = &max_threads,
613 .maxlen = sizeof(int),
614 .mode = 0644,
615 .proc_handler = proc_dointvec,
618 .procname = "random",
619 .mode = 0555,
620 .child = random_table,
623 .procname = "overflowuid",
624 .data = &overflowuid,
625 .maxlen = sizeof(int),
626 .mode = 0644,
627 .proc_handler = proc_dointvec_minmax,
628 .extra1 = &minolduid,
629 .extra2 = &maxolduid,
632 .procname = "overflowgid",
633 .data = &overflowgid,
634 .maxlen = sizeof(int),
635 .mode = 0644,
636 .proc_handler = proc_dointvec_minmax,
637 .extra1 = &minolduid,
638 .extra2 = &maxolduid,
640 #ifdef CONFIG_S390
641 #ifdef CONFIG_MATHEMU
643 .procname = "ieee_emulation_warnings",
644 .data = &sysctl_ieee_emulation_warnings,
645 .maxlen = sizeof(int),
646 .mode = 0644,
647 .proc_handler = proc_dointvec,
649 #endif
651 .procname = "userprocess_debug",
652 .data = &show_unhandled_signals,
653 .maxlen = sizeof(int),
654 .mode = 0644,
655 .proc_handler = proc_dointvec,
657 #endif
659 .procname = "pid_max",
660 .data = &pid_max,
661 .maxlen = sizeof (int),
662 .mode = 0644,
663 .proc_handler = proc_dointvec_minmax,
664 .extra1 = &pid_max_min,
665 .extra2 = &pid_max_max,
668 .procname = "panic_on_oops",
669 .data = &panic_on_oops,
670 .maxlen = sizeof(int),
671 .mode = 0644,
672 .proc_handler = proc_dointvec,
674 #if defined CONFIG_PRINTK
676 .procname = "printk",
677 .data = &console_loglevel,
678 .maxlen = 4*sizeof(int),
679 .mode = 0644,
680 .proc_handler = proc_dointvec,
683 .procname = "printk_ratelimit",
684 .data = &printk_ratelimit_state.interval,
685 .maxlen = sizeof(int),
686 .mode = 0644,
687 .proc_handler = proc_dointvec_jiffies,
690 .procname = "printk_ratelimit_burst",
691 .data = &printk_ratelimit_state.burst,
692 .maxlen = sizeof(int),
693 .mode = 0644,
694 .proc_handler = proc_dointvec,
697 .procname = "printk_delay",
698 .data = &printk_delay_msec,
699 .maxlen = sizeof(int),
700 .mode = 0644,
701 .proc_handler = proc_dointvec_minmax,
702 .extra1 = &zero,
703 .extra2 = &ten_thousand,
705 #endif
707 .procname = "ngroups_max",
708 .data = &ngroups_max,
709 .maxlen = sizeof (int),
710 .mode = 0444,
711 .proc_handler = proc_dointvec,
713 #if defined(CONFIG_LOCKUP_DETECTOR)
715 .procname = "watchdog",
716 .data = &watchdog_enabled,
717 .maxlen = sizeof (int),
718 .mode = 0644,
719 .proc_handler = proc_dowatchdog_enabled,
722 .procname = "watchdog_thresh",
723 .data = &softlockup_thresh,
724 .maxlen = sizeof(int),
725 .mode = 0644,
726 .proc_handler = proc_dowatchdog_thresh,
727 .extra1 = &neg_one,
728 .extra2 = &sixty,
731 .procname = "softlockup_panic",
732 .data = &softlockup_panic,
733 .maxlen = sizeof(int),
734 .mode = 0644,
735 .proc_handler = proc_dointvec_minmax,
736 .extra1 = &zero,
737 .extra2 = &one,
739 #endif
740 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) && !defined(CONFIG_LOCKUP_DETECTOR)
742 .procname = "unknown_nmi_panic",
743 .data = &unknown_nmi_panic,
744 .maxlen = sizeof (int),
745 .mode = 0644,
746 .proc_handler = proc_dointvec,
749 .procname = "nmi_watchdog",
750 .data = &nmi_watchdog_enabled,
751 .maxlen = sizeof (int),
752 .mode = 0644,
753 .proc_handler = proc_nmi_enabled,
755 #endif
756 #if defined(CONFIG_X86)
758 .procname = "panic_on_unrecovered_nmi",
759 .data = &panic_on_unrecovered_nmi,
760 .maxlen = sizeof(int),
761 .mode = 0644,
762 .proc_handler = proc_dointvec,
765 .procname = "panic_on_io_nmi",
766 .data = &panic_on_io_nmi,
767 .maxlen = sizeof(int),
768 .mode = 0644,
769 .proc_handler = proc_dointvec,
772 .procname = "bootloader_type",
773 .data = &bootloader_type,
774 .maxlen = sizeof (int),
775 .mode = 0444,
776 .proc_handler = proc_dointvec,
779 .procname = "bootloader_version",
780 .data = &bootloader_version,
781 .maxlen = sizeof (int),
782 .mode = 0444,
783 .proc_handler = proc_dointvec,
786 .procname = "kstack_depth_to_print",
787 .data = &kstack_depth_to_print,
788 .maxlen = sizeof(int),
789 .mode = 0644,
790 .proc_handler = proc_dointvec,
793 .procname = "io_delay_type",
794 .data = &io_delay_type,
795 .maxlen = sizeof(int),
796 .mode = 0644,
797 .proc_handler = proc_dointvec,
799 #endif
800 #if defined(CONFIG_MMU)
802 .procname = "randomize_va_space",
803 .data = &randomize_va_space,
804 .maxlen = sizeof(int),
805 .mode = 0644,
806 .proc_handler = proc_dointvec,
808 #endif
809 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
811 .procname = "spin_retry",
812 .data = &spin_retry,
813 .maxlen = sizeof (int),
814 .mode = 0644,
815 .proc_handler = proc_dointvec,
817 #endif
818 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
820 .procname = "acpi_video_flags",
821 .data = &acpi_realmode_flags,
822 .maxlen = sizeof (unsigned long),
823 .mode = 0644,
824 .proc_handler = proc_doulongvec_minmax,
826 #endif
827 #ifdef CONFIG_IA64
829 .procname = "ignore-unaligned-usertrap",
830 .data = &no_unaligned_warning,
831 .maxlen = sizeof (int),
832 .mode = 0644,
833 .proc_handler = proc_dointvec,
836 .procname = "unaligned-dump-stack",
837 .data = &unaligned_dump_stack,
838 .maxlen = sizeof (int),
839 .mode = 0644,
840 .proc_handler = proc_dointvec,
842 #endif
843 #ifdef CONFIG_DETECT_HUNG_TASK
845 .procname = "hung_task_panic",
846 .data = &sysctl_hung_task_panic,
847 .maxlen = sizeof(int),
848 .mode = 0644,
849 .proc_handler = proc_dointvec_minmax,
850 .extra1 = &zero,
851 .extra2 = &one,
854 .procname = "hung_task_check_count",
855 .data = &sysctl_hung_task_check_count,
856 .maxlen = sizeof(unsigned long),
857 .mode = 0644,
858 .proc_handler = proc_doulongvec_minmax,
861 .procname = "hung_task_timeout_secs",
862 .data = &sysctl_hung_task_timeout_secs,
863 .maxlen = sizeof(unsigned long),
864 .mode = 0644,
865 .proc_handler = proc_dohung_task_timeout_secs,
868 .procname = "hung_task_warnings",
869 .data = &sysctl_hung_task_warnings,
870 .maxlen = sizeof(unsigned long),
871 .mode = 0644,
872 .proc_handler = proc_doulongvec_minmax,
874 #endif
875 #ifdef CONFIG_COMPAT
877 .procname = "compat-log",
878 .data = &compat_log,
879 .maxlen = sizeof (int),
880 .mode = 0644,
881 .proc_handler = proc_dointvec,
883 #endif
884 #ifdef CONFIG_RT_MUTEXES
886 .procname = "max_lock_depth",
887 .data = &max_lock_depth,
888 .maxlen = sizeof(int),
889 .mode = 0644,
890 .proc_handler = proc_dointvec,
892 #endif
894 .procname = "poweroff_cmd",
895 .data = &poweroff_cmd,
896 .maxlen = POWEROFF_CMD_PATH_LEN,
897 .mode = 0644,
898 .proc_handler = proc_dostring,
900 #ifdef CONFIG_KEYS
902 .procname = "keys",
903 .mode = 0555,
904 .child = key_sysctls,
906 #endif
907 #ifdef CONFIG_RCU_TORTURE_TEST
909 .procname = "rcutorture_runnable",
910 .data = &rcutorture_runnable,
911 .maxlen = sizeof(int),
912 .mode = 0644,
913 .proc_handler = proc_dointvec,
915 #endif
916 #ifdef CONFIG_PERF_EVENTS
918 .procname = "perf_event_paranoid",
919 .data = &sysctl_perf_event_paranoid,
920 .maxlen = sizeof(sysctl_perf_event_paranoid),
921 .mode = 0644,
922 .proc_handler = proc_dointvec,
925 .procname = "perf_event_mlock_kb",
926 .data = &sysctl_perf_event_mlock,
927 .maxlen = sizeof(sysctl_perf_event_mlock),
928 .mode = 0644,
929 .proc_handler = proc_dointvec,
932 .procname = "perf_event_max_sample_rate",
933 .data = &sysctl_perf_event_sample_rate,
934 .maxlen = sizeof(sysctl_perf_event_sample_rate),
935 .mode = 0644,
936 .proc_handler = proc_dointvec,
938 #endif
939 #ifdef CONFIG_KMEMCHECK
941 .procname = "kmemcheck",
942 .data = &kmemcheck_enabled,
943 .maxlen = sizeof(int),
944 .mode = 0644,
945 .proc_handler = proc_dointvec,
947 #endif
948 #ifdef CONFIG_BLOCK
950 .procname = "blk_iopoll",
951 .data = &blk_iopoll_enabled,
952 .maxlen = sizeof(int),
953 .mode = 0644,
954 .proc_handler = proc_dointvec,
956 #endif
958 * NOTE: do not add new entries to this table unless you have read
959 * Documentation/sysctl/ctl_unnumbered.txt
964 static struct ctl_table vm_table[] = {
966 .procname = "overcommit_memory",
967 .data = &sysctl_overcommit_memory,
968 .maxlen = sizeof(sysctl_overcommit_memory),
969 .mode = 0644,
970 .proc_handler = proc_dointvec,
973 .procname = "panic_on_oom",
974 .data = &sysctl_panic_on_oom,
975 .maxlen = sizeof(sysctl_panic_on_oom),
976 .mode = 0644,
977 .proc_handler = proc_dointvec,
980 .procname = "oom_kill_allocating_task",
981 .data = &sysctl_oom_kill_allocating_task,
982 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
983 .mode = 0644,
984 .proc_handler = proc_dointvec,
987 .procname = "oom_dump_tasks",
988 .data = &sysctl_oom_dump_tasks,
989 .maxlen = sizeof(sysctl_oom_dump_tasks),
990 .mode = 0644,
991 .proc_handler = proc_dointvec,
994 .procname = "overcommit_ratio",
995 .data = &sysctl_overcommit_ratio,
996 .maxlen = sizeof(sysctl_overcommit_ratio),
997 .mode = 0644,
998 .proc_handler = proc_dointvec,
1001 .procname = "page-cluster",
1002 .data = &page_cluster,
1003 .maxlen = sizeof(int),
1004 .mode = 0644,
1005 .proc_handler = proc_dointvec,
1008 .procname = "dirty_background_ratio",
1009 .data = &dirty_background_ratio,
1010 .maxlen = sizeof(dirty_background_ratio),
1011 .mode = 0644,
1012 .proc_handler = dirty_background_ratio_handler,
1013 .extra1 = &zero,
1014 .extra2 = &one_hundred,
1017 .procname = "dirty_background_bytes",
1018 .data = &dirty_background_bytes,
1019 .maxlen = sizeof(dirty_background_bytes),
1020 .mode = 0644,
1021 .proc_handler = dirty_background_bytes_handler,
1022 .extra1 = &one_ul,
1025 .procname = "dirty_ratio",
1026 .data = &vm_dirty_ratio,
1027 .maxlen = sizeof(vm_dirty_ratio),
1028 .mode = 0644,
1029 .proc_handler = dirty_ratio_handler,
1030 .extra1 = &zero,
1031 .extra2 = &one_hundred,
1034 .procname = "dirty_bytes",
1035 .data = &vm_dirty_bytes,
1036 .maxlen = sizeof(vm_dirty_bytes),
1037 .mode = 0644,
1038 .proc_handler = dirty_bytes_handler,
1039 .extra1 = &dirty_bytes_min,
1042 .procname = "dirty_writeback_centisecs",
1043 .data = &dirty_writeback_interval,
1044 .maxlen = sizeof(dirty_writeback_interval),
1045 .mode = 0644,
1046 .proc_handler = dirty_writeback_centisecs_handler,
1049 .procname = "dirty_expire_centisecs",
1050 .data = &dirty_expire_interval,
1051 .maxlen = sizeof(dirty_expire_interval),
1052 .mode = 0644,
1053 .proc_handler = proc_dointvec,
1056 .procname = "nr_pdflush_threads",
1057 .data = &nr_pdflush_threads,
1058 .maxlen = sizeof nr_pdflush_threads,
1059 .mode = 0444 /* read-only*/,
1060 .proc_handler = proc_dointvec,
1063 .procname = "swappiness",
1064 .data = &vm_swappiness,
1065 .maxlen = sizeof(vm_swappiness),
1066 .mode = 0644,
1067 .proc_handler = proc_dointvec_minmax,
1068 .extra1 = &zero,
1069 .extra2 = &one_hundred,
1071 #ifdef CONFIG_HUGETLB_PAGE
1073 .procname = "nr_hugepages",
1074 .data = NULL,
1075 .maxlen = sizeof(unsigned long),
1076 .mode = 0644,
1077 .proc_handler = hugetlb_sysctl_handler,
1078 .extra1 = (void *)&hugetlb_zero,
1079 .extra2 = (void *)&hugetlb_infinity,
1081 #ifdef CONFIG_NUMA
1083 .procname = "nr_hugepages_mempolicy",
1084 .data = NULL,
1085 .maxlen = sizeof(unsigned long),
1086 .mode = 0644,
1087 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1088 .extra1 = (void *)&hugetlb_zero,
1089 .extra2 = (void *)&hugetlb_infinity,
1091 #endif
1093 .procname = "hugetlb_shm_group",
1094 .data = &sysctl_hugetlb_shm_group,
1095 .maxlen = sizeof(gid_t),
1096 .mode = 0644,
1097 .proc_handler = proc_dointvec,
1100 .procname = "hugepages_treat_as_movable",
1101 .data = &hugepages_treat_as_movable,
1102 .maxlen = sizeof(int),
1103 .mode = 0644,
1104 .proc_handler = hugetlb_treat_movable_handler,
1107 .procname = "nr_overcommit_hugepages",
1108 .data = NULL,
1109 .maxlen = sizeof(unsigned long),
1110 .mode = 0644,
1111 .proc_handler = hugetlb_overcommit_handler,
1112 .extra1 = (void *)&hugetlb_zero,
1113 .extra2 = (void *)&hugetlb_infinity,
1115 #endif
1117 .procname = "lowmem_reserve_ratio",
1118 .data = &sysctl_lowmem_reserve_ratio,
1119 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1120 .mode = 0644,
1121 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1124 .procname = "drop_caches",
1125 .data = &sysctl_drop_caches,
1126 .maxlen = sizeof(int),
1127 .mode = 0644,
1128 .proc_handler = drop_caches_sysctl_handler,
1130 #ifdef CONFIG_COMPACTION
1132 .procname = "compact_memory",
1133 .data = &sysctl_compact_memory,
1134 .maxlen = sizeof(int),
1135 .mode = 0200,
1136 .proc_handler = sysctl_compaction_handler,
1139 .procname = "extfrag_threshold",
1140 .data = &sysctl_extfrag_threshold,
1141 .maxlen = sizeof(int),
1142 .mode = 0644,
1143 .proc_handler = sysctl_extfrag_handler,
1144 .extra1 = &min_extfrag_threshold,
1145 .extra2 = &max_extfrag_threshold,
1148 #endif /* CONFIG_COMPACTION */
1150 .procname = "min_free_kbytes",
1151 .data = &min_free_kbytes,
1152 .maxlen = sizeof(min_free_kbytes),
1153 .mode = 0644,
1154 .proc_handler = min_free_kbytes_sysctl_handler,
1155 .extra1 = &zero,
1158 .procname = "percpu_pagelist_fraction",
1159 .data = &percpu_pagelist_fraction,
1160 .maxlen = sizeof(percpu_pagelist_fraction),
1161 .mode = 0644,
1162 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1163 .extra1 = &min_percpu_pagelist_fract,
1165 #ifdef CONFIG_MMU
1167 .procname = "max_map_count",
1168 .data = &sysctl_max_map_count,
1169 .maxlen = sizeof(sysctl_max_map_count),
1170 .mode = 0644,
1171 .proc_handler = proc_dointvec_minmax,
1172 .extra1 = &zero,
1174 #else
1176 .procname = "nr_trim_pages",
1177 .data = &sysctl_nr_trim_pages,
1178 .maxlen = sizeof(sysctl_nr_trim_pages),
1179 .mode = 0644,
1180 .proc_handler = proc_dointvec_minmax,
1181 .extra1 = &zero,
1183 #endif
1185 .procname = "laptop_mode",
1186 .data = &laptop_mode,
1187 .maxlen = sizeof(laptop_mode),
1188 .mode = 0644,
1189 .proc_handler = proc_dointvec_jiffies,
1192 .procname = "block_dump",
1193 .data = &block_dump,
1194 .maxlen = sizeof(block_dump),
1195 .mode = 0644,
1196 .proc_handler = proc_dointvec,
1197 .extra1 = &zero,
1200 .procname = "vfs_cache_pressure",
1201 .data = &sysctl_vfs_cache_pressure,
1202 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1203 .mode = 0644,
1204 .proc_handler = proc_dointvec,
1205 .extra1 = &zero,
1207 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1209 .procname = "legacy_va_layout",
1210 .data = &sysctl_legacy_va_layout,
1211 .maxlen = sizeof(sysctl_legacy_va_layout),
1212 .mode = 0644,
1213 .proc_handler = proc_dointvec,
1214 .extra1 = &zero,
1216 #endif
1217 #ifdef CONFIG_NUMA
1219 .procname = "zone_reclaim_mode",
1220 .data = &zone_reclaim_mode,
1221 .maxlen = sizeof(zone_reclaim_mode),
1222 .mode = 0644,
1223 .proc_handler = proc_dointvec,
1224 .extra1 = &zero,
1227 .procname = "min_unmapped_ratio",
1228 .data = &sysctl_min_unmapped_ratio,
1229 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1230 .mode = 0644,
1231 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1232 .extra1 = &zero,
1233 .extra2 = &one_hundred,
1236 .procname = "min_slab_ratio",
1237 .data = &sysctl_min_slab_ratio,
1238 .maxlen = sizeof(sysctl_min_slab_ratio),
1239 .mode = 0644,
1240 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1241 .extra1 = &zero,
1242 .extra2 = &one_hundred,
1244 #endif
1245 #ifdef CONFIG_SMP
1247 .procname = "stat_interval",
1248 .data = &sysctl_stat_interval,
1249 .maxlen = sizeof(sysctl_stat_interval),
1250 .mode = 0644,
1251 .proc_handler = proc_dointvec_jiffies,
1253 #endif
1254 #ifdef CONFIG_MMU
1256 .procname = "mmap_min_addr",
1257 .data = &dac_mmap_min_addr,
1258 .maxlen = sizeof(unsigned long),
1259 .mode = 0644,
1260 .proc_handler = mmap_min_addr_handler,
1262 #endif
1263 #ifdef CONFIG_NUMA
1265 .procname = "numa_zonelist_order",
1266 .data = &numa_zonelist_order,
1267 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1268 .mode = 0644,
1269 .proc_handler = numa_zonelist_order_handler,
1271 #endif
1272 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1273 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1275 .procname = "vdso_enabled",
1276 .data = &vdso_enabled,
1277 .maxlen = sizeof(vdso_enabled),
1278 .mode = 0644,
1279 .proc_handler = proc_dointvec,
1280 .extra1 = &zero,
1282 #endif
1283 #ifdef CONFIG_HIGHMEM
1285 .procname = "highmem_is_dirtyable",
1286 .data = &vm_highmem_is_dirtyable,
1287 .maxlen = sizeof(vm_highmem_is_dirtyable),
1288 .mode = 0644,
1289 .proc_handler = proc_dointvec_minmax,
1290 .extra1 = &zero,
1291 .extra2 = &one,
1293 #endif
1295 .procname = "scan_unevictable_pages",
1296 .data = &scan_unevictable_pages,
1297 .maxlen = sizeof(scan_unevictable_pages),
1298 .mode = 0644,
1299 .proc_handler = scan_unevictable_handler,
1301 #ifdef CONFIG_MEMORY_FAILURE
1303 .procname = "memory_failure_early_kill",
1304 .data = &sysctl_memory_failure_early_kill,
1305 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1306 .mode = 0644,
1307 .proc_handler = proc_dointvec_minmax,
1308 .extra1 = &zero,
1309 .extra2 = &one,
1312 .procname = "memory_failure_recovery",
1313 .data = &sysctl_memory_failure_recovery,
1314 .maxlen = sizeof(sysctl_memory_failure_recovery),
1315 .mode = 0644,
1316 .proc_handler = proc_dointvec_minmax,
1317 .extra1 = &zero,
1318 .extra2 = &one,
1320 #endif
1323 * NOTE: do not add new entries to this table unless you have read
1324 * Documentation/sysctl/ctl_unnumbered.txt
1329 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1330 static struct ctl_table binfmt_misc_table[] = {
1333 #endif
1335 static struct ctl_table fs_table[] = {
1337 .procname = "inode-nr",
1338 .data = &inodes_stat,
1339 .maxlen = 2*sizeof(int),
1340 .mode = 0444,
1341 .proc_handler = proc_nr_inodes,
1344 .procname = "inode-state",
1345 .data = &inodes_stat,
1346 .maxlen = 7*sizeof(int),
1347 .mode = 0444,
1348 .proc_handler = proc_nr_inodes,
1351 .procname = "file-nr",
1352 .data = &files_stat,
1353 .maxlen = sizeof(files_stat),
1354 .mode = 0444,
1355 .proc_handler = proc_nr_files,
1358 .procname = "file-max",
1359 .data = &files_stat.max_files,
1360 .maxlen = sizeof(files_stat.max_files),
1361 .mode = 0644,
1362 .proc_handler = proc_doulongvec_minmax,
1365 .procname = "nr_open",
1366 .data = &sysctl_nr_open,
1367 .maxlen = sizeof(int),
1368 .mode = 0644,
1369 .proc_handler = proc_dointvec_minmax,
1370 .extra1 = &sysctl_nr_open_min,
1371 .extra2 = &sysctl_nr_open_max,
1374 .procname = "dentry-state",
1375 .data = &dentry_stat,
1376 .maxlen = 6*sizeof(int),
1377 .mode = 0444,
1378 .proc_handler = proc_nr_dentry,
1381 .procname = "overflowuid",
1382 .data = &fs_overflowuid,
1383 .maxlen = sizeof(int),
1384 .mode = 0644,
1385 .proc_handler = proc_dointvec_minmax,
1386 .extra1 = &minolduid,
1387 .extra2 = &maxolduid,
1390 .procname = "overflowgid",
1391 .data = &fs_overflowgid,
1392 .maxlen = sizeof(int),
1393 .mode = 0644,
1394 .proc_handler = proc_dointvec_minmax,
1395 .extra1 = &minolduid,
1396 .extra2 = &maxolduid,
1398 #ifdef CONFIG_FILE_LOCKING
1400 .procname = "leases-enable",
1401 .data = &leases_enable,
1402 .maxlen = sizeof(int),
1403 .mode = 0644,
1404 .proc_handler = proc_dointvec,
1406 #endif
1407 #ifdef CONFIG_DNOTIFY
1409 .procname = "dir-notify-enable",
1410 .data = &dir_notify_enable,
1411 .maxlen = sizeof(int),
1412 .mode = 0644,
1413 .proc_handler = proc_dointvec,
1415 #endif
1416 #ifdef CONFIG_MMU
1417 #ifdef CONFIG_FILE_LOCKING
1419 .procname = "lease-break-time",
1420 .data = &lease_break_time,
1421 .maxlen = sizeof(int),
1422 .mode = 0644,
1423 .proc_handler = proc_dointvec,
1425 #endif
1426 #ifdef CONFIG_AIO
1428 .procname = "aio-nr",
1429 .data = &aio_nr,
1430 .maxlen = sizeof(aio_nr),
1431 .mode = 0444,
1432 .proc_handler = proc_doulongvec_minmax,
1435 .procname = "aio-max-nr",
1436 .data = &aio_max_nr,
1437 .maxlen = sizeof(aio_max_nr),
1438 .mode = 0644,
1439 .proc_handler = proc_doulongvec_minmax,
1441 #endif /* CONFIG_AIO */
1442 #ifdef CONFIG_INOTIFY_USER
1444 .procname = "inotify",
1445 .mode = 0555,
1446 .child = inotify_table,
1448 #endif
1449 #ifdef CONFIG_EPOLL
1451 .procname = "epoll",
1452 .mode = 0555,
1453 .child = epoll_table,
1455 #endif
1456 #endif
1458 .procname = "suid_dumpable",
1459 .data = &suid_dumpable,
1460 .maxlen = sizeof(int),
1461 .mode = 0644,
1462 .proc_handler = proc_dointvec_minmax,
1463 .extra1 = &zero,
1464 .extra2 = &two,
1466 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1468 .procname = "binfmt_misc",
1469 .mode = 0555,
1470 .child = binfmt_misc_table,
1472 #endif
1474 .procname = "pipe-max-size",
1475 .data = &pipe_max_size,
1476 .maxlen = sizeof(int),
1477 .mode = 0644,
1478 .proc_handler = &pipe_proc_fn,
1479 .extra1 = &pipe_min_size,
1482 * NOTE: do not add new entries to this table unless you have read
1483 * Documentation/sysctl/ctl_unnumbered.txt
1488 static struct ctl_table debug_table[] = {
1489 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1490 defined(CONFIG_S390)
1492 .procname = "exception-trace",
1493 .data = &show_unhandled_signals,
1494 .maxlen = sizeof(int),
1495 .mode = 0644,
1496 .proc_handler = proc_dointvec
1498 #endif
1499 #if defined(CONFIG_OPTPROBES)
1501 .procname = "kprobes-optimization",
1502 .data = &sysctl_kprobes_optimization,
1503 .maxlen = sizeof(int),
1504 .mode = 0644,
1505 .proc_handler = proc_kprobes_optimization_handler,
1506 .extra1 = &zero,
1507 .extra2 = &one,
1509 #endif
1513 static struct ctl_table dev_table[] = {
1517 static DEFINE_SPINLOCK(sysctl_lock);
1519 /* called under sysctl_lock */
1520 static int use_table(struct ctl_table_header *p)
1522 if (unlikely(p->unregistering))
1523 return 0;
1524 p->used++;
1525 return 1;
1528 /* called under sysctl_lock */
1529 static void unuse_table(struct ctl_table_header *p)
1531 if (!--p->used)
1532 if (unlikely(p->unregistering))
1533 complete(p->unregistering);
1536 /* called under sysctl_lock, will reacquire if has to wait */
1537 static void start_unregistering(struct ctl_table_header *p)
1540 * if p->used is 0, nobody will ever touch that entry again;
1541 * we'll eliminate all paths to it before dropping sysctl_lock
1543 if (unlikely(p->used)) {
1544 struct completion wait;
1545 init_completion(&wait);
1546 p->unregistering = &wait;
1547 spin_unlock(&sysctl_lock);
1548 wait_for_completion(&wait);
1549 spin_lock(&sysctl_lock);
1550 } else {
1551 /* anything non-NULL; we'll never dereference it */
1552 p->unregistering = ERR_PTR(-EINVAL);
1555 * do not remove from the list until nobody holds it; walking the
1556 * list in do_sysctl() relies on that.
1558 list_del_init(&p->ctl_entry);
1561 void sysctl_head_get(struct ctl_table_header *head)
1563 spin_lock(&sysctl_lock);
1564 head->count++;
1565 spin_unlock(&sysctl_lock);
1568 void sysctl_head_put(struct ctl_table_header *head)
1570 spin_lock(&sysctl_lock);
1571 if (!--head->count)
1572 kfree(head);
1573 spin_unlock(&sysctl_lock);
1576 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1578 if (!head)
1579 BUG();
1580 spin_lock(&sysctl_lock);
1581 if (!use_table(head))
1582 head = ERR_PTR(-ENOENT);
1583 spin_unlock(&sysctl_lock);
1584 return head;
1587 void sysctl_head_finish(struct ctl_table_header *head)
1589 if (!head)
1590 return;
1591 spin_lock(&sysctl_lock);
1592 unuse_table(head);
1593 spin_unlock(&sysctl_lock);
1596 static struct ctl_table_set *
1597 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1599 struct ctl_table_set *set = &root->default_set;
1600 if (root->lookup)
1601 set = root->lookup(root, namespaces);
1602 return set;
1605 static struct list_head *
1606 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1608 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1609 return &set->list;
1612 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1613 struct ctl_table_header *prev)
1615 struct ctl_table_root *root;
1616 struct list_head *header_list;
1617 struct ctl_table_header *head;
1618 struct list_head *tmp;
1620 spin_lock(&sysctl_lock);
1621 if (prev) {
1622 head = prev;
1623 tmp = &prev->ctl_entry;
1624 unuse_table(prev);
1625 goto next;
1627 tmp = &root_table_header.ctl_entry;
1628 for (;;) {
1629 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1631 if (!use_table(head))
1632 goto next;
1633 spin_unlock(&sysctl_lock);
1634 return head;
1635 next:
1636 root = head->root;
1637 tmp = tmp->next;
1638 header_list = lookup_header_list(root, namespaces);
1639 if (tmp != header_list)
1640 continue;
1642 do {
1643 root = list_entry(root->root_list.next,
1644 struct ctl_table_root, root_list);
1645 if (root == &sysctl_table_root)
1646 goto out;
1647 header_list = lookup_header_list(root, namespaces);
1648 } while (list_empty(header_list));
1649 tmp = header_list->next;
1651 out:
1652 spin_unlock(&sysctl_lock);
1653 return NULL;
1656 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1658 return __sysctl_head_next(current->nsproxy, prev);
1661 void register_sysctl_root(struct ctl_table_root *root)
1663 spin_lock(&sysctl_lock);
1664 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1665 spin_unlock(&sysctl_lock);
1669 * sysctl_perm does NOT grant the superuser all rights automatically, because
1670 * some sysctl variables are readonly even to root.
1673 static int test_perm(int mode, int op)
1675 if (!current_euid())
1676 mode >>= 6;
1677 else if (in_egroup_p(0))
1678 mode >>= 3;
1679 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1680 return 0;
1681 return -EACCES;
1684 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1686 int error;
1687 int mode;
1689 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1690 if (error)
1691 return error;
1693 if (root->permissions)
1694 mode = root->permissions(root, current->nsproxy, table);
1695 else
1696 mode = table->mode;
1698 return test_perm(mode, op);
1701 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1703 for (; table->procname; table++) {
1704 table->parent = parent;
1705 if (table->child)
1706 sysctl_set_parent(table, table->child);
1710 static __init int sysctl_init(void)
1712 sysctl_set_parent(NULL, root_table);
1713 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1714 sysctl_check_table(current->nsproxy, root_table);
1715 #endif
1716 return 0;
1719 core_initcall(sysctl_init);
1721 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1722 struct ctl_table *table)
1724 struct ctl_table *p;
1725 const char *s = branch->procname;
1727 /* branch should have named subdirectory as its first element */
1728 if (!s || !branch->child)
1729 return NULL;
1731 /* ... and nothing else */
1732 if (branch[1].procname)
1733 return NULL;
1735 /* table should contain subdirectory with the same name */
1736 for (p = table; p->procname; p++) {
1737 if (!p->child)
1738 continue;
1739 if (p->procname && strcmp(p->procname, s) == 0)
1740 return p;
1742 return NULL;
1745 /* see if attaching q to p would be an improvement */
1746 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1748 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1749 struct ctl_table *next;
1750 int is_better = 0;
1751 int not_in_parent = !p->attached_by;
1753 while ((next = is_branch_in(by, to)) != NULL) {
1754 if (by == q->attached_by)
1755 is_better = 1;
1756 if (to == p->attached_by)
1757 not_in_parent = 1;
1758 by = by->child;
1759 to = next->child;
1762 if (is_better && not_in_parent) {
1763 q->attached_by = by;
1764 q->attached_to = to;
1765 q->parent = p;
1770 * __register_sysctl_paths - register a sysctl hierarchy
1771 * @root: List of sysctl headers to register on
1772 * @namespaces: Data to compute which lists of sysctl entries are visible
1773 * @path: The path to the directory the sysctl table is in.
1774 * @table: the top-level table structure
1776 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1777 * array. A completely 0 filled entry terminates the table.
1779 * The members of the &struct ctl_table structure are used as follows:
1781 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1782 * enter a sysctl file
1784 * data - a pointer to data for use by proc_handler
1786 * maxlen - the maximum size in bytes of the data
1788 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1790 * child - a pointer to the child sysctl table if this entry is a directory, or
1791 * %NULL.
1793 * proc_handler - the text handler routine (described below)
1795 * de - for internal use by the sysctl routines
1797 * extra1, extra2 - extra pointers usable by the proc handler routines
1799 * Leaf nodes in the sysctl tree will be represented by a single file
1800 * under /proc; non-leaf nodes will be represented by directories.
1802 * sysctl(2) can automatically manage read and write requests through
1803 * the sysctl table. The data and maxlen fields of the ctl_table
1804 * struct enable minimal validation of the values being written to be
1805 * performed, and the mode field allows minimal authentication.
1807 * There must be a proc_handler routine for any terminal nodes
1808 * mirrored under /proc/sys (non-terminals are handled by a built-in
1809 * directory handler). Several default handlers are available to
1810 * cover common cases -
1812 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1813 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1814 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1816 * It is the handler's job to read the input buffer from user memory
1817 * and process it. The handler should return 0 on success.
1819 * This routine returns %NULL on a failure to register, and a pointer
1820 * to the table header on success.
1822 struct ctl_table_header *__register_sysctl_paths(
1823 struct ctl_table_root *root,
1824 struct nsproxy *namespaces,
1825 const struct ctl_path *path, struct ctl_table *table)
1827 struct ctl_table_header *header;
1828 struct ctl_table *new, **prevp;
1829 unsigned int n, npath;
1830 struct ctl_table_set *set;
1832 /* Count the path components */
1833 for (npath = 0; path[npath].procname; ++npath)
1837 * For each path component, allocate a 2-element ctl_table array.
1838 * The first array element will be filled with the sysctl entry
1839 * for this, the second will be the sentinel (procname == 0).
1841 * We allocate everything in one go so that we don't have to
1842 * worry about freeing additional memory in unregister_sysctl_table.
1844 header = kzalloc(sizeof(struct ctl_table_header) +
1845 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1846 if (!header)
1847 return NULL;
1849 new = (struct ctl_table *) (header + 1);
1851 /* Now connect the dots */
1852 prevp = &header->ctl_table;
1853 for (n = 0; n < npath; ++n, ++path) {
1854 /* Copy the procname */
1855 new->procname = path->procname;
1856 new->mode = 0555;
1858 *prevp = new;
1859 prevp = &new->child;
1861 new += 2;
1863 *prevp = table;
1864 header->ctl_table_arg = table;
1866 INIT_LIST_HEAD(&header->ctl_entry);
1867 header->used = 0;
1868 header->unregistering = NULL;
1869 header->root = root;
1870 sysctl_set_parent(NULL, header->ctl_table);
1871 header->count = 1;
1872 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1873 if (sysctl_check_table(namespaces, header->ctl_table)) {
1874 kfree(header);
1875 return NULL;
1877 #endif
1878 spin_lock(&sysctl_lock);
1879 header->set = lookup_header_set(root, namespaces);
1880 header->attached_by = header->ctl_table;
1881 header->attached_to = root_table;
1882 header->parent = &root_table_header;
1883 for (set = header->set; set; set = set->parent) {
1884 struct ctl_table_header *p;
1885 list_for_each_entry(p, &set->list, ctl_entry) {
1886 if (p->unregistering)
1887 continue;
1888 try_attach(p, header);
1891 header->parent->count++;
1892 list_add_tail(&header->ctl_entry, &header->set->list);
1893 spin_unlock(&sysctl_lock);
1895 return header;
1899 * register_sysctl_table_path - register a sysctl table hierarchy
1900 * @path: The path to the directory the sysctl table is in.
1901 * @table: the top-level table structure
1903 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1904 * array. A completely 0 filled entry terminates the table.
1906 * See __register_sysctl_paths for more details.
1908 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1909 struct ctl_table *table)
1911 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1912 path, table);
1916 * register_sysctl_table - register a sysctl table hierarchy
1917 * @table: the top-level table structure
1919 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1920 * array. A completely 0 filled entry terminates the table.
1922 * See register_sysctl_paths for more details.
1924 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1926 static const struct ctl_path null_path[] = { {} };
1928 return register_sysctl_paths(null_path, table);
1932 * unregister_sysctl_table - unregister a sysctl table hierarchy
1933 * @header: the header returned from register_sysctl_table
1935 * Unregisters the sysctl table and all children. proc entries may not
1936 * actually be removed until they are no longer used by anyone.
1938 void unregister_sysctl_table(struct ctl_table_header * header)
1940 might_sleep();
1942 if (header == NULL)
1943 return;
1945 spin_lock(&sysctl_lock);
1946 start_unregistering(header);
1947 if (!--header->parent->count) {
1948 WARN_ON(1);
1949 kfree(header->parent);
1951 if (!--header->count)
1952 kfree(header);
1953 spin_unlock(&sysctl_lock);
1956 int sysctl_is_seen(struct ctl_table_header *p)
1958 struct ctl_table_set *set = p->set;
1959 int res;
1960 spin_lock(&sysctl_lock);
1961 if (p->unregistering)
1962 res = 0;
1963 else if (!set->is_seen)
1964 res = 1;
1965 else
1966 res = set->is_seen(set);
1967 spin_unlock(&sysctl_lock);
1968 return res;
1971 void setup_sysctl_set(struct ctl_table_set *p,
1972 struct ctl_table_set *parent,
1973 int (*is_seen)(struct ctl_table_set *))
1975 INIT_LIST_HEAD(&p->list);
1976 p->parent = parent ? parent : &sysctl_table_root.default_set;
1977 p->is_seen = is_seen;
1980 #else /* !CONFIG_SYSCTL */
1981 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1983 return NULL;
1986 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1987 struct ctl_table *table)
1989 return NULL;
1992 void unregister_sysctl_table(struct ctl_table_header * table)
1996 void setup_sysctl_set(struct ctl_table_set *p,
1997 struct ctl_table_set *parent,
1998 int (*is_seen)(struct ctl_table_set *))
2002 void sysctl_head_put(struct ctl_table_header *head)
2006 #endif /* CONFIG_SYSCTL */
2009 * /proc/sys support
2012 #ifdef CONFIG_PROC_SYSCTL
2014 static int _proc_do_string(void* data, int maxlen, int write,
2015 void __user *buffer,
2016 size_t *lenp, loff_t *ppos)
2018 size_t len;
2019 char __user *p;
2020 char c;
2022 if (!data || !maxlen || !*lenp) {
2023 *lenp = 0;
2024 return 0;
2027 if (write) {
2028 len = 0;
2029 p = buffer;
2030 while (len < *lenp) {
2031 if (get_user(c, p++))
2032 return -EFAULT;
2033 if (c == 0 || c == '\n')
2034 break;
2035 len++;
2037 if (len >= maxlen)
2038 len = maxlen-1;
2039 if(copy_from_user(data, buffer, len))
2040 return -EFAULT;
2041 ((char *) data)[len] = 0;
2042 *ppos += *lenp;
2043 } else {
2044 len = strlen(data);
2045 if (len > maxlen)
2046 len = maxlen;
2048 if (*ppos > len) {
2049 *lenp = 0;
2050 return 0;
2053 data += *ppos;
2054 len -= *ppos;
2056 if (len > *lenp)
2057 len = *lenp;
2058 if (len)
2059 if(copy_to_user(buffer, data, len))
2060 return -EFAULT;
2061 if (len < *lenp) {
2062 if(put_user('\n', ((char __user *) buffer) + len))
2063 return -EFAULT;
2064 len++;
2066 *lenp = len;
2067 *ppos += len;
2069 return 0;
2073 * proc_dostring - read a string sysctl
2074 * @table: the sysctl table
2075 * @write: %TRUE if this is a write to the sysctl file
2076 * @buffer: the user buffer
2077 * @lenp: the size of the user buffer
2078 * @ppos: file position
2080 * Reads/writes a string from/to the user buffer. If the kernel
2081 * buffer provided is not large enough to hold the string, the
2082 * string is truncated. The copied string is %NULL-terminated.
2083 * If the string is being read by the user process, it is copied
2084 * and a newline '\n' is added. It is truncated if the buffer is
2085 * not large enough.
2087 * Returns 0 on success.
2089 int proc_dostring(struct ctl_table *table, int write,
2090 void __user *buffer, size_t *lenp, loff_t *ppos)
2092 return _proc_do_string(table->data, table->maxlen, write,
2093 buffer, lenp, ppos);
2096 static size_t proc_skip_spaces(char **buf)
2098 size_t ret;
2099 char *tmp = skip_spaces(*buf);
2100 ret = tmp - *buf;
2101 *buf = tmp;
2102 return ret;
2105 static void proc_skip_char(char **buf, size_t *size, const char v)
2107 while (*size) {
2108 if (**buf != v)
2109 break;
2110 (*size)--;
2111 (*buf)++;
2115 #define TMPBUFLEN 22
2117 * proc_get_long - reads an ASCII formatted integer from a user buffer
2119 * @buf: a kernel buffer
2120 * @size: size of the kernel buffer
2121 * @val: this is where the number will be stored
2122 * @neg: set to %TRUE if number is negative
2123 * @perm_tr: a vector which contains the allowed trailers
2124 * @perm_tr_len: size of the perm_tr vector
2125 * @tr: pointer to store the trailer character
2127 * In case of success %0 is returned and @buf and @size are updated with
2128 * the amount of bytes read. If @tr is non-NULL and a trailing
2129 * character exists (size is non-zero after returning from this
2130 * function), @tr is updated with the trailing character.
2132 static int proc_get_long(char **buf, size_t *size,
2133 unsigned long *val, bool *neg,
2134 const char *perm_tr, unsigned perm_tr_len, char *tr)
2136 int len;
2137 char *p, tmp[TMPBUFLEN];
2139 if (!*size)
2140 return -EINVAL;
2142 len = *size;
2143 if (len > TMPBUFLEN - 1)
2144 len = TMPBUFLEN - 1;
2146 memcpy(tmp, *buf, len);
2148 tmp[len] = 0;
2149 p = tmp;
2150 if (*p == '-' && *size > 1) {
2151 *neg = true;
2152 p++;
2153 } else
2154 *neg = false;
2155 if (!isdigit(*p))
2156 return -EINVAL;
2158 *val = simple_strtoul(p, &p, 0);
2160 len = p - tmp;
2162 /* We don't know if the next char is whitespace thus we may accept
2163 * invalid integers (e.g. 1234...a) or two integers instead of one
2164 * (e.g. 123...1). So lets not allow such large numbers. */
2165 if (len == TMPBUFLEN - 1)
2166 return -EINVAL;
2168 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2169 return -EINVAL;
2171 if (tr && (len < *size))
2172 *tr = *p;
2174 *buf += len;
2175 *size -= len;
2177 return 0;
2181 * proc_put_long - converts an integer to a decimal ASCII formatted string
2183 * @buf: the user buffer
2184 * @size: the size of the user buffer
2185 * @val: the integer to be converted
2186 * @neg: sign of the number, %TRUE for negative
2188 * In case of success %0 is returned and @buf and @size are updated with
2189 * the amount of bytes written.
2191 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2192 bool neg)
2194 int len;
2195 char tmp[TMPBUFLEN], *p = tmp;
2197 sprintf(p, "%s%lu", neg ? "-" : "", val);
2198 len = strlen(tmp);
2199 if (len > *size)
2200 len = *size;
2201 if (copy_to_user(*buf, tmp, len))
2202 return -EFAULT;
2203 *size -= len;
2204 *buf += len;
2205 return 0;
2207 #undef TMPBUFLEN
2209 static int proc_put_char(void __user **buf, size_t *size, char c)
2211 if (*size) {
2212 char __user **buffer = (char __user **)buf;
2213 if (put_user(c, *buffer))
2214 return -EFAULT;
2215 (*size)--, (*buffer)++;
2216 *buf = *buffer;
2218 return 0;
2221 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2222 int *valp,
2223 int write, void *data)
2225 if (write) {
2226 *valp = *negp ? -*lvalp : *lvalp;
2227 } else {
2228 int val = *valp;
2229 if (val < 0) {
2230 *negp = true;
2231 *lvalp = (unsigned long)-val;
2232 } else {
2233 *negp = false;
2234 *lvalp = (unsigned long)val;
2237 return 0;
2240 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2242 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2243 int write, void __user *buffer,
2244 size_t *lenp, loff_t *ppos,
2245 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2246 int write, void *data),
2247 void *data)
2249 int *i, vleft, first = 1, err = 0;
2250 unsigned long page = 0;
2251 size_t left;
2252 char *kbuf;
2254 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2255 *lenp = 0;
2256 return 0;
2259 i = (int *) tbl_data;
2260 vleft = table->maxlen / sizeof(*i);
2261 left = *lenp;
2263 if (!conv)
2264 conv = do_proc_dointvec_conv;
2266 if (write) {
2267 if (left > PAGE_SIZE - 1)
2268 left = PAGE_SIZE - 1;
2269 page = __get_free_page(GFP_TEMPORARY);
2270 kbuf = (char *) page;
2271 if (!kbuf)
2272 return -ENOMEM;
2273 if (copy_from_user(kbuf, buffer, left)) {
2274 err = -EFAULT;
2275 goto free;
2277 kbuf[left] = 0;
2280 for (; left && vleft--; i++, first=0) {
2281 unsigned long lval;
2282 bool neg;
2284 if (write) {
2285 left -= proc_skip_spaces(&kbuf);
2287 if (!left)
2288 break;
2289 err = proc_get_long(&kbuf, &left, &lval, &neg,
2290 proc_wspace_sep,
2291 sizeof(proc_wspace_sep), NULL);
2292 if (err)
2293 break;
2294 if (conv(&neg, &lval, i, 1, data)) {
2295 err = -EINVAL;
2296 break;
2298 } else {
2299 if (conv(&neg, &lval, i, 0, data)) {
2300 err = -EINVAL;
2301 break;
2303 if (!first)
2304 err = proc_put_char(&buffer, &left, '\t');
2305 if (err)
2306 break;
2307 err = proc_put_long(&buffer, &left, lval, neg);
2308 if (err)
2309 break;
2313 if (!write && !first && left && !err)
2314 err = proc_put_char(&buffer, &left, '\n');
2315 if (write && !err && left)
2316 left -= proc_skip_spaces(&kbuf);
2317 free:
2318 if (write) {
2319 free_page(page);
2320 if (first)
2321 return err ? : -EINVAL;
2323 *lenp -= left;
2324 *ppos += *lenp;
2325 return err;
2328 static int do_proc_dointvec(struct ctl_table *table, int write,
2329 void __user *buffer, size_t *lenp, loff_t *ppos,
2330 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2331 int write, void *data),
2332 void *data)
2334 return __do_proc_dointvec(table->data, table, write,
2335 buffer, lenp, ppos, conv, data);
2339 * proc_dointvec - read a vector of integers
2340 * @table: the sysctl table
2341 * @write: %TRUE if this is a write to the sysctl file
2342 * @buffer: the user buffer
2343 * @lenp: the size of the user buffer
2344 * @ppos: file position
2346 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2347 * values from/to the user buffer, treated as an ASCII string.
2349 * Returns 0 on success.
2351 int proc_dointvec(struct ctl_table *table, int write,
2352 void __user *buffer, size_t *lenp, loff_t *ppos)
2354 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2355 NULL,NULL);
2359 * Taint values can only be increased
2360 * This means we can safely use a temporary.
2362 static int proc_taint(struct ctl_table *table, int write,
2363 void __user *buffer, size_t *lenp, loff_t *ppos)
2365 struct ctl_table t;
2366 unsigned long tmptaint = get_taint();
2367 int err;
2369 if (write && !capable(CAP_SYS_ADMIN))
2370 return -EPERM;
2372 t = *table;
2373 t.data = &tmptaint;
2374 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2375 if (err < 0)
2376 return err;
2378 if (write) {
2380 * Poor man's atomic or. Not worth adding a primitive
2381 * to everyone's atomic.h for this
2383 int i;
2384 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2385 if ((tmptaint >> i) & 1)
2386 add_taint(i);
2390 return err;
2393 struct do_proc_dointvec_minmax_conv_param {
2394 int *min;
2395 int *max;
2398 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2399 int *valp,
2400 int write, void *data)
2402 struct do_proc_dointvec_minmax_conv_param *param = data;
2403 if (write) {
2404 int val = *negp ? -*lvalp : *lvalp;
2405 if ((param->min && *param->min > val) ||
2406 (param->max && *param->max < val))
2407 return -EINVAL;
2408 *valp = val;
2409 } else {
2410 int val = *valp;
2411 if (val < 0) {
2412 *negp = true;
2413 *lvalp = (unsigned long)-val;
2414 } else {
2415 *negp = false;
2416 *lvalp = (unsigned long)val;
2419 return 0;
2423 * proc_dointvec_minmax - read a vector of integers with min/max values
2424 * @table: the sysctl table
2425 * @write: %TRUE if this is a write to the sysctl file
2426 * @buffer: the user buffer
2427 * @lenp: the size of the user buffer
2428 * @ppos: file position
2430 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2431 * values from/to the user buffer, treated as an ASCII string.
2433 * This routine will ensure the values are within the range specified by
2434 * table->extra1 (min) and table->extra2 (max).
2436 * Returns 0 on success.
2438 int proc_dointvec_minmax(struct ctl_table *table, int write,
2439 void __user *buffer, size_t *lenp, loff_t *ppos)
2441 struct do_proc_dointvec_minmax_conv_param param = {
2442 .min = (int *) table->extra1,
2443 .max = (int *) table->extra2,
2445 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2446 do_proc_dointvec_minmax_conv, &param);
2449 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2450 void __user *buffer,
2451 size_t *lenp, loff_t *ppos,
2452 unsigned long convmul,
2453 unsigned long convdiv)
2455 unsigned long *i, *min, *max;
2456 int vleft, first = 1, err = 0;
2457 unsigned long page = 0;
2458 size_t left;
2459 char *kbuf;
2461 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2462 *lenp = 0;
2463 return 0;
2466 i = (unsigned long *) data;
2467 min = (unsigned long *) table->extra1;
2468 max = (unsigned long *) table->extra2;
2469 vleft = table->maxlen / sizeof(unsigned long);
2470 left = *lenp;
2472 if (write) {
2473 if (left > PAGE_SIZE - 1)
2474 left = PAGE_SIZE - 1;
2475 page = __get_free_page(GFP_TEMPORARY);
2476 kbuf = (char *) page;
2477 if (!kbuf)
2478 return -ENOMEM;
2479 if (copy_from_user(kbuf, buffer, left)) {
2480 err = -EFAULT;
2481 goto free;
2483 kbuf[left] = 0;
2486 for (; left && vleft--; i++, first = 0) {
2487 unsigned long val;
2489 if (write) {
2490 bool neg;
2492 left -= proc_skip_spaces(&kbuf);
2494 err = proc_get_long(&kbuf, &left, &val, &neg,
2495 proc_wspace_sep,
2496 sizeof(proc_wspace_sep), NULL);
2497 if (err)
2498 break;
2499 if (neg)
2500 continue;
2501 if ((min && val < *min) || (max && val > *max))
2502 continue;
2503 *i = val;
2504 } else {
2505 val = convdiv * (*i) / convmul;
2506 if (!first)
2507 err = proc_put_char(&buffer, &left, '\t');
2508 err = proc_put_long(&buffer, &left, val, false);
2509 if (err)
2510 break;
2514 if (!write && !first && left && !err)
2515 err = proc_put_char(&buffer, &left, '\n');
2516 if (write && !err)
2517 left -= proc_skip_spaces(&kbuf);
2518 free:
2519 if (write) {
2520 free_page(page);
2521 if (first)
2522 return err ? : -EINVAL;
2524 *lenp -= left;
2525 *ppos += *lenp;
2526 return err;
2529 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2530 void __user *buffer,
2531 size_t *lenp, loff_t *ppos,
2532 unsigned long convmul,
2533 unsigned long convdiv)
2535 return __do_proc_doulongvec_minmax(table->data, table, write,
2536 buffer, lenp, ppos, convmul, convdiv);
2540 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2541 * @table: the sysctl table
2542 * @write: %TRUE if this is a write to the sysctl file
2543 * @buffer: the user buffer
2544 * @lenp: the size of the user buffer
2545 * @ppos: file position
2547 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2548 * values from/to the user buffer, treated as an ASCII string.
2550 * This routine will ensure the values are within the range specified by
2551 * table->extra1 (min) and table->extra2 (max).
2553 * Returns 0 on success.
2555 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2556 void __user *buffer, size_t *lenp, loff_t *ppos)
2558 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2562 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2563 * @table: the sysctl table
2564 * @write: %TRUE if this is a write to the sysctl file
2565 * @buffer: the user buffer
2566 * @lenp: the size of the user buffer
2567 * @ppos: file position
2569 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2570 * values from/to the user buffer, treated as an ASCII string. The values
2571 * are treated as milliseconds, and converted to jiffies when they are stored.
2573 * This routine will ensure the values are within the range specified by
2574 * table->extra1 (min) and table->extra2 (max).
2576 * Returns 0 on success.
2578 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2579 void __user *buffer,
2580 size_t *lenp, loff_t *ppos)
2582 return do_proc_doulongvec_minmax(table, write, buffer,
2583 lenp, ppos, HZ, 1000l);
2587 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2588 int *valp,
2589 int write, void *data)
2591 if (write) {
2592 if (*lvalp > LONG_MAX / HZ)
2593 return 1;
2594 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2595 } else {
2596 int val = *valp;
2597 unsigned long lval;
2598 if (val < 0) {
2599 *negp = true;
2600 lval = (unsigned long)-val;
2601 } else {
2602 *negp = false;
2603 lval = (unsigned long)val;
2605 *lvalp = lval / HZ;
2607 return 0;
2610 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2611 int *valp,
2612 int write, void *data)
2614 if (write) {
2615 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2616 return 1;
2617 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2618 } else {
2619 int val = *valp;
2620 unsigned long lval;
2621 if (val < 0) {
2622 *negp = true;
2623 lval = (unsigned long)-val;
2624 } else {
2625 *negp = false;
2626 lval = (unsigned long)val;
2628 *lvalp = jiffies_to_clock_t(lval);
2630 return 0;
2633 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2634 int *valp,
2635 int write, void *data)
2637 if (write) {
2638 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2639 } else {
2640 int val = *valp;
2641 unsigned long lval;
2642 if (val < 0) {
2643 *negp = true;
2644 lval = (unsigned long)-val;
2645 } else {
2646 *negp = false;
2647 lval = (unsigned long)val;
2649 *lvalp = jiffies_to_msecs(lval);
2651 return 0;
2655 * proc_dointvec_jiffies - read a vector of integers as seconds
2656 * @table: the sysctl table
2657 * @write: %TRUE if this is a write to the sysctl file
2658 * @buffer: the user buffer
2659 * @lenp: the size of the user buffer
2660 * @ppos: file position
2662 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2663 * values from/to the user buffer, treated as an ASCII string.
2664 * The values read are assumed to be in seconds, and are converted into
2665 * jiffies.
2667 * Returns 0 on success.
2669 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2670 void __user *buffer, size_t *lenp, loff_t *ppos)
2672 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2673 do_proc_dointvec_jiffies_conv,NULL);
2677 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2678 * @table: the sysctl table
2679 * @write: %TRUE if this is a write to the sysctl file
2680 * @buffer: the user buffer
2681 * @lenp: the size of the user buffer
2682 * @ppos: pointer to the file position
2684 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2685 * values from/to the user buffer, treated as an ASCII string.
2686 * The values read are assumed to be in 1/USER_HZ seconds, and
2687 * are converted into jiffies.
2689 * Returns 0 on success.
2691 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2692 void __user *buffer, size_t *lenp, loff_t *ppos)
2694 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2695 do_proc_dointvec_userhz_jiffies_conv,NULL);
2699 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2700 * @table: the sysctl table
2701 * @write: %TRUE if this is a write to the sysctl file
2702 * @buffer: the user buffer
2703 * @lenp: the size of the user buffer
2704 * @ppos: file position
2705 * @ppos: the current position in the file
2707 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2708 * values from/to the user buffer, treated as an ASCII string.
2709 * The values read are assumed to be in 1/1000 seconds, and
2710 * are converted into jiffies.
2712 * Returns 0 on success.
2714 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2715 void __user *buffer, size_t *lenp, loff_t *ppos)
2717 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2718 do_proc_dointvec_ms_jiffies_conv, NULL);
2721 static int proc_do_cad_pid(struct ctl_table *table, int write,
2722 void __user *buffer, size_t *lenp, loff_t *ppos)
2724 struct pid *new_pid;
2725 pid_t tmp;
2726 int r;
2728 tmp = pid_vnr(cad_pid);
2730 r = __do_proc_dointvec(&tmp, table, write, buffer,
2731 lenp, ppos, NULL, NULL);
2732 if (r || !write)
2733 return r;
2735 new_pid = find_get_pid(tmp);
2736 if (!new_pid)
2737 return -ESRCH;
2739 put_pid(xchg(&cad_pid, new_pid));
2740 return 0;
2744 * proc_do_large_bitmap - read/write from/to a large bitmap
2745 * @table: the sysctl table
2746 * @write: %TRUE if this is a write to the sysctl file
2747 * @buffer: the user buffer
2748 * @lenp: the size of the user buffer
2749 * @ppos: file position
2751 * The bitmap is stored at table->data and the bitmap length (in bits)
2752 * in table->maxlen.
2754 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2755 * large bitmaps may be represented in a compact manner. Writing into
2756 * the file will clear the bitmap then update it with the given input.
2758 * Returns 0 on success.
2760 int proc_do_large_bitmap(struct ctl_table *table, int write,
2761 void __user *buffer, size_t *lenp, loff_t *ppos)
2763 int err = 0;
2764 bool first = 1;
2765 size_t left = *lenp;
2766 unsigned long bitmap_len = table->maxlen;
2767 unsigned long *bitmap = (unsigned long *) table->data;
2768 unsigned long *tmp_bitmap = NULL;
2769 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2771 if (!bitmap_len || !left || (*ppos && !write)) {
2772 *lenp = 0;
2773 return 0;
2776 if (write) {
2777 unsigned long page = 0;
2778 char *kbuf;
2780 if (left > PAGE_SIZE - 1)
2781 left = PAGE_SIZE - 1;
2783 page = __get_free_page(GFP_TEMPORARY);
2784 kbuf = (char *) page;
2785 if (!kbuf)
2786 return -ENOMEM;
2787 if (copy_from_user(kbuf, buffer, left)) {
2788 free_page(page);
2789 return -EFAULT;
2791 kbuf[left] = 0;
2793 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2794 GFP_KERNEL);
2795 if (!tmp_bitmap) {
2796 free_page(page);
2797 return -ENOMEM;
2799 proc_skip_char(&kbuf, &left, '\n');
2800 while (!err && left) {
2801 unsigned long val_a, val_b;
2802 bool neg;
2804 err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2805 sizeof(tr_a), &c);
2806 if (err)
2807 break;
2808 if (val_a >= bitmap_len || neg) {
2809 err = -EINVAL;
2810 break;
2813 val_b = val_a;
2814 if (left) {
2815 kbuf++;
2816 left--;
2819 if (c == '-') {
2820 err = proc_get_long(&kbuf, &left, &val_b,
2821 &neg, tr_b, sizeof(tr_b),
2822 &c);
2823 if (err)
2824 break;
2825 if (val_b >= bitmap_len || neg ||
2826 val_a > val_b) {
2827 err = -EINVAL;
2828 break;
2830 if (left) {
2831 kbuf++;
2832 left--;
2836 while (val_a <= val_b)
2837 set_bit(val_a++, tmp_bitmap);
2839 first = 0;
2840 proc_skip_char(&kbuf, &left, '\n');
2842 free_page(page);
2843 } else {
2844 unsigned long bit_a, bit_b = 0;
2846 while (left) {
2847 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2848 if (bit_a >= bitmap_len)
2849 break;
2850 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2851 bit_a + 1) - 1;
2853 if (!first) {
2854 err = proc_put_char(&buffer, &left, ',');
2855 if (err)
2856 break;
2858 err = proc_put_long(&buffer, &left, bit_a, false);
2859 if (err)
2860 break;
2861 if (bit_a != bit_b) {
2862 err = proc_put_char(&buffer, &left, '-');
2863 if (err)
2864 break;
2865 err = proc_put_long(&buffer, &left, bit_b, false);
2866 if (err)
2867 break;
2870 first = 0; bit_b++;
2872 if (!err)
2873 err = proc_put_char(&buffer, &left, '\n');
2876 if (!err) {
2877 if (write) {
2878 if (*ppos)
2879 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2880 else
2881 memcpy(bitmap, tmp_bitmap,
2882 BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2884 kfree(tmp_bitmap);
2885 *lenp -= left;
2886 *ppos += *lenp;
2887 return 0;
2888 } else {
2889 kfree(tmp_bitmap);
2890 return err;
2894 #else /* CONFIG_PROC_FS */
2896 int proc_dostring(struct ctl_table *table, int write,
2897 void __user *buffer, size_t *lenp, loff_t *ppos)
2899 return -ENOSYS;
2902 int proc_dointvec(struct ctl_table *table, int write,
2903 void __user *buffer, size_t *lenp, loff_t *ppos)
2905 return -ENOSYS;
2908 int proc_dointvec_minmax(struct ctl_table *table, int write,
2909 void __user *buffer, size_t *lenp, loff_t *ppos)
2911 return -ENOSYS;
2914 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2915 void __user *buffer, size_t *lenp, loff_t *ppos)
2917 return -ENOSYS;
2920 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2921 void __user *buffer, size_t *lenp, loff_t *ppos)
2923 return -ENOSYS;
2926 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2927 void __user *buffer, size_t *lenp, loff_t *ppos)
2929 return -ENOSYS;
2932 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2933 void __user *buffer, size_t *lenp, loff_t *ppos)
2935 return -ENOSYS;
2938 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2939 void __user *buffer,
2940 size_t *lenp, loff_t *ppos)
2942 return -ENOSYS;
2946 #endif /* CONFIG_PROC_FS */
2949 * No sense putting this after each symbol definition, twice,
2950 * exception granted :-)
2952 EXPORT_SYMBOL(proc_dointvec);
2953 EXPORT_SYMBOL(proc_dointvec_jiffies);
2954 EXPORT_SYMBOL(proc_dointvec_minmax);
2955 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2956 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2957 EXPORT_SYMBOL(proc_dostring);
2958 EXPORT_SYMBOL(proc_doulongvec_minmax);
2959 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2960 EXPORT_SYMBOL(register_sysctl_table);
2961 EXPORT_SYMBOL(register_sysctl_paths);
2962 EXPORT_SYMBOL(unregister_sysctl_table);