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[net-next-2.6.git] / kernel / sysctl.c
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1da177e4
LT		 1/*
2 * sysctl.c: General linux system control interface
3 *
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
19 */
20
1da177e4
LT		 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>
c59ede7b 27#include <linux/capability.h>
1da177e4
LT		 28#include <linux/ctype.h>
29#include <linux/utsname.h>
30#include <linux/capability.h>
31#include <linux/smp_lock.h>
32#include <linux/init.h>
33#include <linux/kernel.h>
0296b228 34#include <linux/kobject.h>
20380731 35#include <linux/net.h>
1da177e4
LT		 36#include <linux/sysrq.h>
37#include <linux/highuid.h>
38#include <linux/writeback.h>
39#include <linux/hugetlb.h>
40#include <linux/security.h>
41#include <linux/initrd.h>
42#include <linux/times.h>
43#include <linux/limits.h>
44#include <linux/dcache.h>
45#include <linux/syscalls.h>
c255d844
PM		 46#include <linux/nfs_fs.h>
47#include <linux/acpi.h>
1da177e4
LT		 48
49#include <asm/uaccess.h>
50#include <asm/processor.h>
51
529bf6be
DS		 52extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
53 void __user *buffer, size_t *lenp, loff_t *ppos);
54
29cbc78b
AK		 55#ifdef CONFIG_X86
56#include <asm/nmi.h>
0741f4d2 57#include <asm/stacktrace.h>
29cbc78b
AK		 58#endif
59
1da177e4
LT		 60#if defined(CONFIG_SYSCTL)
61
62/* External variables not in a header file. */
63extern int C_A_D;
64extern int sysctl_overcommit_memory;
65extern int sysctl_overcommit_ratio;
fadd8fbd 66extern int sysctl_panic_on_oom;
1da177e4 67extern int max_threads;
1da177e4 68extern int core_uses_pid;
d6e71144 69extern int suid_dumpable;
1da177e4 70extern char core_pattern[];
1da177e4
LT		 71extern int pid_max;
72extern int min_free_kbytes;
73extern int printk_ratelimit_jiffies;
74extern int printk_ratelimit_burst;
75extern int pid_max_min, pid_max_max;
9d0243bc 76extern int sysctl_drop_caches;
8ad4b1fb 77extern int percpu_pagelist_fraction;
bebfa101 78extern int compat_log;
5096add8 79extern int maps_protect;
77461ab3 80extern int sysctl_stat_interval;
1da177e4 81
1da177e4
LT		 82/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
83static int maxolduid = 65535;
84static int minolduid;
8ad4b1fb 85static int min_percpu_pagelist_fract = 8;
1da177e4
LT		 86
87static int ngroups_max = NGROUPS_MAX;
88
89#ifdef CONFIG_KMOD
90extern char modprobe_path[];
91#endif
1da177e4
LT		 92#ifdef CONFIG_CHR_DEV_SG
93extern int sg_big_buff;
94#endif
1da177e4
LT		 95
96#ifdef __sparc__
97extern char reboot_command [];
98extern int stop_a_enabled;
99extern int scons_pwroff;
100#endif
101
102#ifdef __hppa__
103extern int pwrsw_enabled;
104extern int unaligned_enabled;
105#endif
106
347a8dc3 107#ifdef CONFIG_S390
1da177e4
LT		 108#ifdef CONFIG_MATHEMU
109extern int sysctl_ieee_emulation_warnings;
110#endif
111extern int sysctl_userprocess_debug;
951f22d5 112extern int spin_retry;
1da177e4
LT		 113#endif
114
115extern int sysctl_hz_timer;
116
117#ifdef CONFIG_BSD_PROCESS_ACCT
118extern int acct_parm[];
119#endif
120
d2b176ed
JS		 121#ifdef CONFIG_IA64
122extern int no_unaligned_warning;
123#endif
124
23f78d4a
IM		 125#ifdef CONFIG_RT_MUTEXES
126extern int max_lock_depth;
127#endif
128
b89a8171
EB		 129#ifdef CONFIG_SYSCTL_SYSCALL
130static int parse_table(int __user *, int, void __user *, size_t __user *,
1f29bcd7 131 void __user *, size_t, ctl_table *);
b89a8171
EB		 132#endif
133
6b49a257 134
d6f8ff73 135#ifdef CONFIG_PROC_SYSCTL
9ec52099
CLG		 136static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
137 void __user *buffer, size_t *lenp, loff_t *ppos);
34f5a398
TT		 138static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
139 void __user *buffer, size_t *lenp, loff_t *ppos);
d6f8ff73 140#endif
9ec52099 141
1da177e4
LT		 142static ctl_table root_table[];
143static struct ctl_table_header root_table_header =
144 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
145
146static ctl_table kern_table[];
147static ctl_table vm_table[];
1da177e4
LT		 148static ctl_table fs_table[];
149static ctl_table debug_table[];
150static ctl_table dev_table[];
151extern ctl_table random_table[];
152#ifdef CONFIG_UNIX98_PTYS
153extern ctl_table pty_table[];
154#endif
2d9048e2 155#ifdef CONFIG_INOTIFY_USER
0399cb08
RL		 156extern ctl_table inotify_table[];
157#endif
1da177e4
LT		 158
159#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
160int sysctl_legacy_va_layout;
161#endif
162
9bc9a6bd 163
1da177e4
LT		 164/* The default sysctl tables: */
165
166static ctl_table root_table[] = {
167 {
168 .ctl_name = CTL_KERN,
169 .procname = "kernel",
170 .mode = 0555,
171 .child = kern_table,
172 },
173 {
174 .ctl_name = CTL_VM,
175 .procname = "vm",
176 .mode = 0555,
177 .child = vm_table,
178 },
179#ifdef CONFIG_NET
180 {
181 .ctl_name = CTL_NET,
182 .procname = "net",
183 .mode = 0555,
184 .child = net_table,
185 },
186#endif
1da177e4
LT		 187 {
188 .ctl_name = CTL_FS,
189 .procname = "fs",
190 .mode = 0555,
191 .child = fs_table,
192 },
193 {
194 .ctl_name = CTL_DEBUG,
195 .procname = "debug",
196 .mode = 0555,
197 .child = debug_table,
198 },
199 {
200 .ctl_name = CTL_DEV,
201 .procname = "dev",
202 .mode = 0555,
203 .child = dev_table,
204 },
0eeca283 205
1da177e4
LT		 206 { .ctl_name = 0 }
207};
208
209static ctl_table kern_table[] = {
1da177e4
LT		 210 {
211 .ctl_name = KERN_PANIC,
212 .procname = "panic",
213 .data = &panic_timeout,
214 .maxlen = sizeof(int),
215 .mode = 0644,
216 .proc_handler = &proc_dointvec,
217 },
218 {
219 .ctl_name = KERN_CORE_USES_PID,
220 .procname = "core_uses_pid",
221 .data = &core_uses_pid,
222 .maxlen = sizeof(int),
223 .mode = 0644,
224 .proc_handler = &proc_dointvec,
225 },
226 {
227 .ctl_name = KERN_CORE_PATTERN,
228 .procname = "core_pattern",
229 .data = core_pattern,
d025c9db 230 .maxlen = 128,
1da177e4
LT		 231 .mode = 0644,
232 .proc_handler = &proc_dostring,
233 .strategy = &sysctl_string,
234 },
34f5a398 235#ifdef CONFIG_PROC_SYSCTL
1da177e4
LT		 236 {
237 .ctl_name = KERN_TAINTED,
238 .procname = "tainted",
239 .data = &tainted,
240 .maxlen = sizeof(int),
34f5a398
TT		 241 .mode = 0644,
242 .proc_handler = &proc_dointvec_taint,
1da177e4 243 },
34f5a398 244#endif
1da177e4
LT		 245 {
246 .ctl_name = KERN_CAP_BSET,
247 .procname = "cap-bound",
248 .data = &cap_bset,
249 .maxlen = sizeof(kernel_cap_t),
250 .mode = 0600,
251 .proc_handler = &proc_dointvec_bset,
252 },
253#ifdef CONFIG_BLK_DEV_INITRD
254 {
255 .ctl_name = KERN_REALROOTDEV,
256 .procname = "real-root-dev",
257 .data = &real_root_dev,
258 .maxlen = sizeof(int),
259 .mode = 0644,
260 .proc_handler = &proc_dointvec,
261 },
262#endif
263#ifdef __sparc__
264 {
265 .ctl_name = KERN_SPARC_REBOOT,
266 .procname = "reboot-cmd",
267 .data = reboot_command,
268 .maxlen = 256,
269 .mode = 0644,
270 .proc_handler = &proc_dostring,
271 .strategy = &sysctl_string,
272 },
273 {
274 .ctl_name = KERN_SPARC_STOP_A,
275 .procname = "stop-a",
276 .data = &stop_a_enabled,
277 .maxlen = sizeof (int),
278 .mode = 0644,
279 .proc_handler = &proc_dointvec,
280 },
281 {
282 .ctl_name = KERN_SPARC_SCONS_PWROFF,
283 .procname = "scons-poweroff",
284 .data = &scons_pwroff,
285 .maxlen = sizeof (int),
286 .mode = 0644,
287 .proc_handler = &proc_dointvec,
288 },
289#endif
290#ifdef __hppa__
291 {
292 .ctl_name = KERN_HPPA_PWRSW,
293 .procname = "soft-power",
294 .data = &pwrsw_enabled,
295 .maxlen = sizeof (int),
296 .mode = 0644,
297 .proc_handler = &proc_dointvec,
298 },
299 {
300 .ctl_name = KERN_HPPA_UNALIGNED,
301 .procname = "unaligned-trap",
302 .data = &unaligned_enabled,
303 .maxlen = sizeof (int),
304 .mode = 0644,
305 .proc_handler = &proc_dointvec,
306 },
307#endif
308 {
309 .ctl_name = KERN_CTLALTDEL,
310 .procname = "ctrl-alt-del",
311 .data = &C_A_D,
312 .maxlen = sizeof(int),
313 .mode = 0644,
314 .proc_handler = &proc_dointvec,
315 },
316 {
317 .ctl_name = KERN_PRINTK,
318 .procname = "printk",
319 .data = &console_loglevel,
320 .maxlen = 4*sizeof(int),
321 .mode = 0644,
322 .proc_handler = &proc_dointvec,
323 },
324#ifdef CONFIG_KMOD
325 {
326 .ctl_name = KERN_MODPROBE,
327 .procname = "modprobe",
328 .data = &modprobe_path,
329 .maxlen = KMOD_PATH_LEN,
330 .mode = 0644,
331 .proc_handler = &proc_dostring,
332 .strategy = &sysctl_string,
333 },
334#endif
57ae2508 335#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
1da177e4
LT		 336 {
337 .ctl_name = KERN_HOTPLUG,
338 .procname = "hotplug",
312c004d
KS		 339 .data = &uevent_helper,
340 .maxlen = UEVENT_HELPER_PATH_LEN,
1da177e4
LT		 341 .mode = 0644,
342 .proc_handler = &proc_dostring,
343 .strategy = &sysctl_string,
344 },
345#endif
346#ifdef CONFIG_CHR_DEV_SG
347 {
348 .ctl_name = KERN_SG_BIG_BUFF,
349 .procname = "sg-big-buff",
350 .data = &sg_big_buff,
351 .maxlen = sizeof (int),
352 .mode = 0444,
353 .proc_handler = &proc_dointvec,
354 },
355#endif
356#ifdef CONFIG_BSD_PROCESS_ACCT
357 {
358 .ctl_name = KERN_ACCT,
359 .procname = "acct",
360 .data = &acct_parm,
361 .maxlen = 3*sizeof(int),
362 .mode = 0644,
363 .proc_handler = &proc_dointvec,
364 },
365#endif
1da177e4
LT		 366#ifdef CONFIG_MAGIC_SYSRQ
367 {
368 .ctl_name = KERN_SYSRQ,
369 .procname = "sysrq",
5d6f647f 370 .data = &__sysrq_enabled,
1da177e4
LT		 371 .maxlen = sizeof (int),
372 .mode = 0644,
373 .proc_handler = &proc_dointvec,
374 },
375#endif
d6f8ff73 376#ifdef CONFIG_PROC_SYSCTL
1da177e4
LT		 377 {
378 .ctl_name = KERN_CADPID,
379 .procname = "cad_pid",
9ec52099 380 .data = NULL,
1da177e4
LT		 381 .maxlen = sizeof (int),
382 .mode = 0600,
9ec52099 383 .proc_handler = &proc_do_cad_pid,
1da177e4 384 },
d6f8ff73 385#endif
1da177e4
LT		 386 {
387 .ctl_name = KERN_MAX_THREADS,
388 .procname = "threads-max",
389 .data = &max_threads,
390 .maxlen = sizeof(int),
391 .mode = 0644,
392 .proc_handler = &proc_dointvec,
393 },
394 {
395 .ctl_name = KERN_RANDOM,
396 .procname = "random",
397 .mode = 0555,
398 .child = random_table,
399 },
400#ifdef CONFIG_UNIX98_PTYS
401 {
402 .ctl_name = KERN_PTY,
403 .procname = "pty",
404 .mode = 0555,
405 .child = pty_table,
406 },
407#endif
408 {
409 .ctl_name = KERN_OVERFLOWUID,
410 .procname = "overflowuid",
411 .data = &overflowuid,
412 .maxlen = sizeof(int),
413 .mode = 0644,
414 .proc_handler = &proc_dointvec_minmax,
415 .strategy = &sysctl_intvec,
416 .extra1 = &minolduid,
417 .extra2 = &maxolduid,
418 },
419 {
420 .ctl_name = KERN_OVERFLOWGID,
421 .procname = "overflowgid",
422 .data = &overflowgid,
423 .maxlen = sizeof(int),
424 .mode = 0644,
425 .proc_handler = &proc_dointvec_minmax,
426 .strategy = &sysctl_intvec,
427 .extra1 = &minolduid,
428 .extra2 = &maxolduid,
429 },
347a8dc3 430#ifdef CONFIG_S390
1da177e4
LT		 431#ifdef CONFIG_MATHEMU
432 {
433 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
434 .procname = "ieee_emulation_warnings",
435 .data = &sysctl_ieee_emulation_warnings,
436 .maxlen = sizeof(int),
437 .mode = 0644,
438 .proc_handler = &proc_dointvec,
439 },
440#endif
441#ifdef CONFIG_NO_IDLE_HZ
442 {
443 .ctl_name = KERN_HZ_TIMER,
444 .procname = "hz_timer",
445 .data = &sysctl_hz_timer,
446 .maxlen = sizeof(int),
447 .mode = 0644,
448 .proc_handler = &proc_dointvec,
449 },
450#endif
451 {
452 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
453 .procname = "userprocess_debug",
454 .data = &sysctl_userprocess_debug,
455 .maxlen = sizeof(int),
456 .mode = 0644,
457 .proc_handler = &proc_dointvec,
458 },
459#endif
460 {
461 .ctl_name = KERN_PIDMAX,
462 .procname = "pid_max",
463 .data = &pid_max,
464 .maxlen = sizeof (int),
465 .mode = 0644,
466 .proc_handler = &proc_dointvec_minmax,
467 .strategy = sysctl_intvec,
468 .extra1 = &pid_max_min,
469 .extra2 = &pid_max_max,
470 },
471 {
472 .ctl_name = KERN_PANIC_ON_OOPS,
473 .procname = "panic_on_oops",
474 .data = &panic_on_oops,
475 .maxlen = sizeof(int),
476 .mode = 0644,
477 .proc_handler = &proc_dointvec,
478 },
479 {
480 .ctl_name = KERN_PRINTK_RATELIMIT,
481 .procname = "printk_ratelimit",
482 .data = &printk_ratelimit_jiffies,
483 .maxlen = sizeof(int),
484 .mode = 0644,
485 .proc_handler = &proc_dointvec_jiffies,
486 .strategy = &sysctl_jiffies,
487 },
488 {
489 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
490 .procname = "printk_ratelimit_burst",
491 .data = &printk_ratelimit_burst,
492 .maxlen = sizeof(int),
493 .mode = 0644,
494 .proc_handler = &proc_dointvec,
495 },
496 {
497 .ctl_name = KERN_NGROUPS_MAX,
498 .procname = "ngroups_max",
499 .data = &ngroups_max,
500 .maxlen = sizeof (int),
501 .mode = 0444,
502 .proc_handler = &proc_dointvec,
503 },
504#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
505 {
506 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
507 .procname = "unknown_nmi_panic",
508 .data = &unknown_nmi_panic,
509 .maxlen = sizeof (int),
510 .mode = 0644,
2fbe7b25 511 .proc_handler = &proc_dointvec,
1da177e4 512 },
407984f1
DZ		 513 {
514 .ctl_name = KERN_NMI_WATCHDOG,
515 .procname = "nmi_watchdog",
516 .data = &nmi_watchdog_enabled,
517 .maxlen = sizeof (int),
518 .mode = 0644,
519 .proc_handler = &proc_nmi_enabled,
1da177e4
LT		 520 },
521#endif
522#if defined(CONFIG_X86)
8da5adda
DZ		 523 {
524 .ctl_name = KERN_PANIC_ON_NMI,
525 .procname = "panic_on_unrecovered_nmi",
526 .data = &panic_on_unrecovered_nmi,
527 .maxlen = sizeof(int),
528 .mode = 0644,
529 .proc_handler = &proc_dointvec,
530 },
1da177e4
LT		 531 {
532 .ctl_name = KERN_BOOTLOADER_TYPE,
533 .procname = "bootloader_type",
534 .data = &bootloader_type,
535 .maxlen = sizeof (int),
536 .mode = 0444,
537 .proc_handler = &proc_dointvec,
538 },
0741f4d2
CE		 539 {
540 .ctl_name = CTL_UNNUMBERED,
541 .procname = "kstack_depth_to_print",
542 .data = &kstack_depth_to_print,
543 .maxlen = sizeof(int),
544 .mode = 0644,
545 .proc_handler = &proc_dointvec,
546 },
1da177e4 547#endif
7a9166e3 548#if defined(CONFIG_MMU)
1da177e4
LT		 549 {
550 .ctl_name = KERN_RANDOMIZE,
551 .procname = "randomize_va_space",
552 .data = &randomize_va_space,
553 .maxlen = sizeof(int),
554 .mode = 0644,
555 .proc_handler = &proc_dointvec,
556 },
7a9166e3 557#endif
0152fb37 558#if defined(CONFIG_S390) && defined(CONFIG_SMP)
951f22d5
MS		 559 {
560 .ctl_name = KERN_SPIN_RETRY,
561 .procname = "spin_retry",
562 .data = &spin_retry,
563 .maxlen = sizeof (int),
564 .mode = 0644,
565 .proc_handler = &proc_dointvec,
566 },
c255d844
PM		 567#endif
568#ifdef CONFIG_ACPI_SLEEP
569 {
570 .ctl_name = KERN_ACPI_VIDEO_FLAGS,
571 .procname = "acpi_video_flags",
572 .data = &acpi_video_flags,
573 .maxlen = sizeof (unsigned long),
574 .mode = 0644,
7f99f06f 575 .proc_handler = &proc_doulongvec_minmax,
c255d844 576 },
d2b176ed
JS		 577#endif
578#ifdef CONFIG_IA64
579 {
580 .ctl_name = KERN_IA64_UNALIGNED,
581 .procname = "ignore-unaligned-usertrap",
582 .data = &no_unaligned_warning,
583 .maxlen = sizeof (int),
584 .mode = 0644,
585 .proc_handler = &proc_dointvec,
586 },
bebfa101
AK		 587#endif
588#ifdef CONFIG_COMPAT
589 {
590 .ctl_name = KERN_COMPAT_LOG,
591 .procname = "compat-log",
592 .data = &compat_log,
593 .maxlen = sizeof (int),
594 .mode = 0644,
595 .proc_handler = &proc_dointvec,
596 },
951f22d5 597#endif
23f78d4a
IM		 598#ifdef CONFIG_RT_MUTEXES
599 {
600 .ctl_name = KERN_MAX_LOCK_DEPTH,
601 .procname = "max_lock_depth",
602 .data = &max_lock_depth,
603 .maxlen = sizeof(int),
604 .mode = 0644,
605 .proc_handler = &proc_dointvec,
606 },
607#endif
5096add8
KC		 608#ifdef CONFIG_PROC_FS
609 {
610 .ctl_name = CTL_UNNUMBERED,
611 .procname = "maps_protect",
612 .data = &maps_protect,
613 .maxlen = sizeof(int),
614 .mode = 0644,
615 .proc_handler = &proc_dointvec,
616 },
617#endif
23f78d4a 618
1da177e4
LT		 619 { .ctl_name = 0 }
620};
621
622/* Constants for minimum and maximum testing in vm_table.
623 We use these as one-element integer vectors. */
624static int zero;
625static int one_hundred = 100;
626
627
628static ctl_table vm_table[] = {
629 {
630 .ctl_name = VM_OVERCOMMIT_MEMORY,
631 .procname = "overcommit_memory",
632 .data = &sysctl_overcommit_memory,
633 .maxlen = sizeof(sysctl_overcommit_memory),
634 .mode = 0644,
635 .proc_handler = &proc_dointvec,
636 },
fadd8fbd
KH		 637 {
638 .ctl_name = VM_PANIC_ON_OOM,
639 .procname = "panic_on_oom",
640 .data = &sysctl_panic_on_oom,
641 .maxlen = sizeof(sysctl_panic_on_oom),
642 .mode = 0644,
643 .proc_handler = &proc_dointvec,
644 },
1da177e4
LT		 645 {
646 .ctl_name = VM_OVERCOMMIT_RATIO,
647 .procname = "overcommit_ratio",
648 .data = &sysctl_overcommit_ratio,
649 .maxlen = sizeof(sysctl_overcommit_ratio),
650 .mode = 0644,
651 .proc_handler = &proc_dointvec,
652 },
653 {
654 .ctl_name = VM_PAGE_CLUSTER,
655 .procname = "page-cluster",
656 .data = &page_cluster,
657 .maxlen = sizeof(int),
658 .mode = 0644,
659 .proc_handler = &proc_dointvec,
660 },
661 {
662 .ctl_name = VM_DIRTY_BACKGROUND,
663 .procname = "dirty_background_ratio",
664 .data = &dirty_background_ratio,
665 .maxlen = sizeof(dirty_background_ratio),
666 .mode = 0644,
667 .proc_handler = &proc_dointvec_minmax,
668 .strategy = &sysctl_intvec,
669 .extra1 = &zero,
670 .extra2 = &one_hundred,
671 },
672 {
673 .ctl_name = VM_DIRTY_RATIO,
674 .procname = "dirty_ratio",
675 .data = &vm_dirty_ratio,
676 .maxlen = sizeof(vm_dirty_ratio),
677 .mode = 0644,
678 .proc_handler = &proc_dointvec_minmax,
679 .strategy = &sysctl_intvec,
680 .extra1 = &zero,
681 .extra2 = &one_hundred,
682 },
683 {
684 .ctl_name = VM_DIRTY_WB_CS,
685 .procname = "dirty_writeback_centisecs",
f6ef9438
BS		 686 .data = &dirty_writeback_interval,
687 .maxlen = sizeof(dirty_writeback_interval),
1da177e4
LT		 688 .mode = 0644,
689 .proc_handler = &dirty_writeback_centisecs_handler,
690 },
691 {
692 .ctl_name = VM_DIRTY_EXPIRE_CS,
693 .procname = "dirty_expire_centisecs",
f6ef9438
BS		 694 .data = &dirty_expire_interval,
695 .maxlen = sizeof(dirty_expire_interval),
1da177e4 696 .mode = 0644,
f6ef9438 697 .proc_handler = &proc_dointvec_userhz_jiffies,
1da177e4
LT		 698 },
699 {
700 .ctl_name = VM_NR_PDFLUSH_THREADS,
701 .procname = "nr_pdflush_threads",
702 .data = &nr_pdflush_threads,
703 .maxlen = sizeof nr_pdflush_threads,
704 .mode = 0444 /* read-only*/,
705 .proc_handler = &proc_dointvec,
706 },
707 {
708 .ctl_name = VM_SWAPPINESS,
709 .procname = "swappiness",
710 .data = &vm_swappiness,
711 .maxlen = sizeof(vm_swappiness),
712 .mode = 0644,
713 .proc_handler = &proc_dointvec_minmax,
714 .strategy = &sysctl_intvec,
715 .extra1 = &zero,
716 .extra2 = &one_hundred,
717 },
718#ifdef CONFIG_HUGETLB_PAGE
719 {
720 .ctl_name = VM_HUGETLB_PAGES,
721 .procname = "nr_hugepages",
722 .data = &max_huge_pages,
723 .maxlen = sizeof(unsigned long),
724 .mode = 0644,
725 .proc_handler = &hugetlb_sysctl_handler,
726 .extra1 = (void *)&hugetlb_zero,
727 .extra2 = (void *)&hugetlb_infinity,
728 },
729 {
730 .ctl_name = VM_HUGETLB_GROUP,
731 .procname = "hugetlb_shm_group",
732 .data = &sysctl_hugetlb_shm_group,
733 .maxlen = sizeof(gid_t),
734 .mode = 0644,
735 .proc_handler = &proc_dointvec,
736 },
737#endif
738 {
739 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
740 .procname = "lowmem_reserve_ratio",
741 .data = &sysctl_lowmem_reserve_ratio,
742 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
743 .mode = 0644,
744 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
745 .strategy = &sysctl_intvec,
746 },
9d0243bc
AM		 747 {
748 .ctl_name = VM_DROP_PAGECACHE,
749 .procname = "drop_caches",
750 .data = &sysctl_drop_caches,
751 .maxlen = sizeof(int),
752 .mode = 0644,
753 .proc_handler = drop_caches_sysctl_handler,
754 .strategy = &sysctl_intvec,
755 },
1da177e4
LT		 756 {
757 .ctl_name = VM_MIN_FREE_KBYTES,
758 .procname = "min_free_kbytes",
759 .data = &min_free_kbytes,
760 .maxlen = sizeof(min_free_kbytes),
761 .mode = 0644,
762 .proc_handler = &min_free_kbytes_sysctl_handler,
763 .strategy = &sysctl_intvec,
764 .extra1 = &zero,
765 },
8ad4b1fb
RS		 766 {
767 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
768 .procname = "percpu_pagelist_fraction",
769 .data = &percpu_pagelist_fraction,
770 .maxlen = sizeof(percpu_pagelist_fraction),
771 .mode = 0644,
772 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
773 .strategy = &sysctl_intvec,
774 .extra1 = &min_percpu_pagelist_fract,
775 },
1da177e4
LT		 776#ifdef CONFIG_MMU
777 {
778 .ctl_name = VM_MAX_MAP_COUNT,
779 .procname = "max_map_count",
780 .data = &sysctl_max_map_count,
781 .maxlen = sizeof(sysctl_max_map_count),
782 .mode = 0644,
783 .proc_handler = &proc_dointvec
784 },
785#endif
786 {
787 .ctl_name = VM_LAPTOP_MODE,
788 .procname = "laptop_mode",
789 .data = &laptop_mode,
790 .maxlen = sizeof(laptop_mode),
791 .mode = 0644,
ed5b43f1
BS		 792 .proc_handler = &proc_dointvec_jiffies,
793 .strategy = &sysctl_jiffies,
1da177e4
LT		 794 },
795 {
796 .ctl_name = VM_BLOCK_DUMP,
797 .procname = "block_dump",
798 .data = &block_dump,
799 .maxlen = sizeof(block_dump),
800 .mode = 0644,
801 .proc_handler = &proc_dointvec,
802 .strategy = &sysctl_intvec,
803 .extra1 = &zero,
804 },
805 {
806 .ctl_name = VM_VFS_CACHE_PRESSURE,
807 .procname = "vfs_cache_pressure",
808 .data = &sysctl_vfs_cache_pressure,
809 .maxlen = sizeof(sysctl_vfs_cache_pressure),
810 .mode = 0644,
811 .proc_handler = &proc_dointvec,
812 .strategy = &sysctl_intvec,
813 .extra1 = &zero,
814 },
815#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
816 {
817 .ctl_name = VM_LEGACY_VA_LAYOUT,
818 .procname = "legacy_va_layout",
819 .data = &sysctl_legacy_va_layout,
820 .maxlen = sizeof(sysctl_legacy_va_layout),
821 .mode = 0644,
822 .proc_handler = &proc_dointvec,
823 .strategy = &sysctl_intvec,
824 .extra1 = &zero,
825 },
826#endif
1743660b
CL		 827#ifdef CONFIG_NUMA
828 {
829 .ctl_name = VM_ZONE_RECLAIM_MODE,
830 .procname = "zone_reclaim_mode",
831 .data = &zone_reclaim_mode,
832 .maxlen = sizeof(zone_reclaim_mode),
833 .mode = 0644,
834 .proc_handler = &proc_dointvec,
c84db23c
CL		 835 .strategy = &sysctl_intvec,
836 .extra1 = &zero,
1743660b 837 },
9614634f
CL		 838 {
839 .ctl_name = VM_MIN_UNMAPPED,
840 .procname = "min_unmapped_ratio",
841 .data = &sysctl_min_unmapped_ratio,
842 .maxlen = sizeof(sysctl_min_unmapped_ratio),
843 .mode = 0644,
844 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
845 .strategy = &sysctl_intvec,
846 .extra1 = &zero,
847 .extra2 = &one_hundred,
848 },
0ff38490
CL		 849 {
850 .ctl_name = VM_MIN_SLAB,
851 .procname = "min_slab_ratio",
852 .data = &sysctl_min_slab_ratio,
853 .maxlen = sizeof(sysctl_min_slab_ratio),
854 .mode = 0644,
855 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
856 .strategy = &sysctl_intvec,
857 .extra1 = &zero,
858 .extra2 = &one_hundred,
859 },
e6e5494c 860#endif
77461ab3
CL		 861#ifdef CONFIG_SMP
862 {
863 .ctl_name = CTL_UNNUMBERED,
864 .procname = "stat_interval",
865 .data = &sysctl_stat_interval,
866 .maxlen = sizeof(sysctl_stat_interval),
867 .mode = 0644,
868 .proc_handler = &proc_dointvec_jiffies,
869 .strategy = &sysctl_jiffies,
870 },
871#endif
5c36e657
PM		 872#if defined(CONFIG_X86_32) || \
873 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
e6e5494c
IM		 874 {
875 .ctl_name = VM_VDSO_ENABLED,
876 .procname = "vdso_enabled",
877 .data = &vdso_enabled,
878 .maxlen = sizeof(vdso_enabled),
879 .mode = 0644,
880 .proc_handler = &proc_dointvec,
881 .strategy = &sysctl_intvec,
882 .extra1 = &zero,
883 },
1da177e4
LT		 884#endif
885 { .ctl_name = 0 }
886};
887
2abc26fc
EB		 888#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
889static ctl_table binfmt_misc_table[] = {
890 { .ctl_name = 0 }
891};
892#endif
893
1da177e4
LT		 894static ctl_table fs_table[] = {
895 {
896 .ctl_name = FS_NRINODE,
897 .procname = "inode-nr",
898 .data = &inodes_stat,
899 .maxlen = 2*sizeof(int),
900 .mode = 0444,
901 .proc_handler = &proc_dointvec,
902 },
903 {
904 .ctl_name = FS_STATINODE,
905 .procname = "inode-state",
906 .data = &inodes_stat,
907 .maxlen = 7*sizeof(int),
908 .mode = 0444,
909 .proc_handler = &proc_dointvec,
910 },
911 {
912 .ctl_name = FS_NRFILE,
913 .procname = "file-nr",
914 .data = &files_stat,
915 .maxlen = 3*sizeof(int),
916 .mode = 0444,
529bf6be 917 .proc_handler = &proc_nr_files,
1da177e4
LT		 918 },
919 {
920 .ctl_name = FS_MAXFILE,
921 .procname = "file-max",
922 .data = &files_stat.max_files,
923 .maxlen = sizeof(int),
924 .mode = 0644,
925 .proc_handler = &proc_dointvec,
926 },
927 {
928 .ctl_name = FS_DENTRY,
929 .procname = "dentry-state",
930 .data = &dentry_stat,
931 .maxlen = 6*sizeof(int),
932 .mode = 0444,
933 .proc_handler = &proc_dointvec,
934 },
935 {
936 .ctl_name = FS_OVERFLOWUID,
937 .procname = "overflowuid",
938 .data = &fs_overflowuid,
939 .maxlen = sizeof(int),
940 .mode = 0644,
941 .proc_handler = &proc_dointvec_minmax,
942 .strategy = &sysctl_intvec,
943 .extra1 = &minolduid,
944 .extra2 = &maxolduid,
945 },
946 {
947 .ctl_name = FS_OVERFLOWGID,
948 .procname = "overflowgid",
949 .data = &fs_overflowgid,
950 .maxlen = sizeof(int),
951 .mode = 0644,
952 .proc_handler = &proc_dointvec_minmax,
953 .strategy = &sysctl_intvec,
954 .extra1 = &minolduid,
955 .extra2 = &maxolduid,
956 },
957 {
958 .ctl_name = FS_LEASES,
959 .procname = "leases-enable",
960 .data = &leases_enable,
961 .maxlen = sizeof(int),
962 .mode = 0644,
963 .proc_handler = &proc_dointvec,
964 },
965#ifdef CONFIG_DNOTIFY
966 {
967 .ctl_name = FS_DIR_NOTIFY,
968 .procname = "dir-notify-enable",
969 .data = &dir_notify_enable,
970 .maxlen = sizeof(int),
971 .mode = 0644,
972 .proc_handler = &proc_dointvec,
973 },
974#endif
975#ifdef CONFIG_MMU
976 {
977 .ctl_name = FS_LEASE_TIME,
978 .procname = "lease-break-time",
979 .data = &lease_break_time,
980 .maxlen = sizeof(int),
981 .mode = 0644,
982 .proc_handler = &proc_dointvec,
983 },
984 {
985 .ctl_name = FS_AIO_NR,
986 .procname = "aio-nr",
987 .data = &aio_nr,
988 .maxlen = sizeof(aio_nr),
989 .mode = 0444,
d55b5fda 990 .proc_handler = &proc_doulongvec_minmax,
1da177e4
LT		 991 },
992 {
993 .ctl_name = FS_AIO_MAX_NR,
994 .procname = "aio-max-nr",
995 .data = &aio_max_nr,
996 .maxlen = sizeof(aio_max_nr),
997 .mode = 0644,
d55b5fda 998 .proc_handler = &proc_doulongvec_minmax,
1da177e4 999 },
2d9048e2 1000#ifdef CONFIG_INOTIFY_USER
0399cb08
RL		 1001 {
1002 .ctl_name = FS_INOTIFY,
1003 .procname = "inotify",
1004 .mode = 0555,
1005 .child = inotify_table,
1006 },
1007#endif
1da177e4 1008#endif
d6e71144
AC		 1009 {
1010 .ctl_name = KERN_SETUID_DUMPABLE,
1011 .procname = "suid_dumpable",
1012 .data = &suid_dumpable,
1013 .maxlen = sizeof(int),
1014 .mode = 0644,
1015 .proc_handler = &proc_dointvec,
1016 },
2abc26fc
EB		 1017#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1018 {
1019 .ctl_name = CTL_UNNUMBERED,
1020 .procname = "binfmt_misc",
1021 .mode = 0555,
1022 .child = binfmt_misc_table,
1023 },
1024#endif
1da177e4
LT		 1025 { .ctl_name = 0 }
1026};
1027
1028static ctl_table debug_table[] = {
1029 { .ctl_name = 0 }
1030};
1031
1032static ctl_table dev_table[] = {
1033 { .ctl_name = 0 }
0eeca283 1034};
1da177e4 1035
330d57fb
AV		 1036static DEFINE_SPINLOCK(sysctl_lock);
1037
1038/* called under sysctl_lock */
1039static int use_table(struct ctl_table_header *p)
1040{
1041 if (unlikely(p->unregistering))
1042 return 0;
1043 p->used++;
1044 return 1;
1045}
1046
1047/* called under sysctl_lock */
1048static void unuse_table(struct ctl_table_header *p)
1049{
1050 if (!--p->used)
1051 if (unlikely(p->unregistering))
1052 complete(p->unregistering);
1053}
1054
1055/* called under sysctl_lock, will reacquire if has to wait */
1056static void start_unregistering(struct ctl_table_header *p)
1057{
1058 /*
1059 * if p->used is 0, nobody will ever touch that entry again;
1060 * we'll eliminate all paths to it before dropping sysctl_lock
1061 */
1062 if (unlikely(p->used)) {
1063 struct completion wait;
1064 init_completion(&wait);
1065 p->unregistering = &wait;
1066 spin_unlock(&sysctl_lock);
1067 wait_for_completion(&wait);
1068 spin_lock(&sysctl_lock);
1069 }
1070 /*
1071 * do not remove from the list until nobody holds it; walking the
1072 * list in do_sysctl() relies on that.
1073 */
1074 list_del_init(&p->ctl_entry);
1075}
1076
805b5d5e
EB		 1077void sysctl_head_finish(struct ctl_table_header *head)
1078{
1079 if (!head)
1080 return;
1081 spin_lock(&sysctl_lock);
1082 unuse_table(head);
1083 spin_unlock(&sysctl_lock);
1084}
1085
1086struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1087{
1088 struct ctl_table_header *head;
1089 struct list_head *tmp;
1090 spin_lock(&sysctl_lock);
1091 if (prev) {
1092 tmp = &prev->ctl_entry;
1093 unuse_table(prev);
1094 goto next;
1095 }
1096 tmp = &root_table_header.ctl_entry;
1097 for (;;) {
1098 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1099
1100 if (!use_table(head))
1101 goto next;
1102 spin_unlock(&sysctl_lock);
1103 return head;
1104 next:
1105 tmp = tmp->next;
1106 if (tmp == &root_table_header.ctl_entry)
1107 break;
1108 }
1109 spin_unlock(&sysctl_lock);
1110 return NULL;
1111}
1112
b89a8171 1113#ifdef CONFIG_SYSCTL_SYSCALL
1da177e4
LT		 1114int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1115 void __user *newval, size_t newlen)
1116{
805b5d5e 1117 struct ctl_table_header *head;
330d57fb 1118 int error = -ENOTDIR;
1da177e4
LT		 1119
1120 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1121 return -ENOTDIR;
1122 if (oldval) {
1123 int old_len;
1124 if (!oldlenp || get_user(old_len, oldlenp))
1125 return -EFAULT;
1126 }
330d57fb 1127
805b5d5e
EB		 1128 for (head = sysctl_head_next(NULL); head;
1129 head = sysctl_head_next(head)) {
330d57fb 1130 error = parse_table(name, nlen, oldval, oldlenp,
1f29bcd7 1131 newval, newlen, head->ctl_table);
805b5d5e
EB		 1132 if (error != -ENOTDIR) {
1133 sysctl_head_finish(head);
330d57fb 1134 break;
805b5d5e
EB		 1135 }
1136 }
330d57fb 1137 return error;
1da177e4
LT		 1138}
1139
1140asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1141{
1142 struct __sysctl_args tmp;
1143 int error;
1144
1145 if (copy_from_user(&tmp, args, sizeof(tmp)))
1146 return -EFAULT;
1147
1148 lock_kernel();
1149 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1150 tmp.newval, tmp.newlen);
1151 unlock_kernel();
1152 return error;
1153}
b89a8171 1154#endif /* CONFIG_SYSCTL_SYSCALL */
1da177e4
LT		 1155
1156/*
1ff007eb 1157 * sysctl_perm does NOT grant the superuser all rights automatically, because
1da177e4
LT		 1158 * some sysctl variables are readonly even to root.
1159 */
1160
1161static int test_perm(int mode, int op)
1162{
1163 if (!current->euid)
1164 mode >>= 6;
1165 else if (in_egroup_p(0))
1166 mode >>= 3;
1167 if ((mode & op & 0007) == op)
1168 return 0;
1169 return -EACCES;
1170}
1171
1ff007eb 1172int sysctl_perm(ctl_table *table, int op)
1da177e4
LT		 1173{
1174 int error;
1175 error = security_sysctl(table, op);
1176 if (error)
1177 return error;
1178 return test_perm(table->mode, op);
1179}
1180
b89a8171 1181#ifdef CONFIG_SYSCTL_SYSCALL
1da177e4
LT		 1182static int parse_table(int __user *name, int nlen,
1183 void __user *oldval, size_t __user *oldlenp,
1184 void __user *newval, size_t newlen,
1f29bcd7 1185 ctl_table *table)
1da177e4
LT		 1186{
1187 int n;
1188repeat:
1189 if (!nlen)
1190 return -ENOTDIR;
1191 if (get_user(n, name))
1192 return -EFAULT;
d99f160a
EB		 1193 for ( ; table->ctl_name || table->procname; table++) {
1194 if (!table->ctl_name)
1195 continue;
6703ddfc 1196 if (n == table->ctl_name) {
1da177e4
LT		 1197 int error;
1198 if (table->child) {
1ff007eb 1199 if (sysctl_perm(table, 001))
1da177e4 1200 return -EPERM;
1da177e4
LT		 1201 name++;
1202 nlen--;
1203 table = table->child;
1204 goto repeat;
1205 }
1206 error = do_sysctl_strategy(table, name, nlen,
1207 oldval, oldlenp,
1f29bcd7 1208 newval, newlen);
1da177e4
LT		 1209 return error;
1210 }
1211 }
1212 return -ENOTDIR;
1213}
1214
1215/* Perform the actual read/write of a sysctl table entry. */
1216int do_sysctl_strategy (ctl_table *table,
1217 int __user *name, int nlen,
1218 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 1219 void __user *newval, size_t newlen)
1da177e4
LT		 1220{
1221 int op = 0, rc;
1222 size_t len;
1223
1224 if (oldval)
1225 op |= 004;
1226 if (newval)
1227 op |= 002;
1ff007eb 1228 if (sysctl_perm(table, op))
1da177e4
LT		 1229 return -EPERM;
1230
1231 if (table->strategy) {
1232 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1f29bcd7 1233 newval, newlen);
1da177e4
LT		 1234 if (rc < 0)
1235 return rc;
1236 if (rc > 0)
1237 return 0;
1238 }
1239
1240 /* If there is no strategy routine, or if the strategy returns
1241 * zero, proceed with automatic r/w */
1242 if (table->data && table->maxlen) {
1243 if (oldval && oldlenp) {
1244 if (get_user(len, oldlenp))
1245 return -EFAULT;
1246 if (len) {
1247 if (len > table->maxlen)
1248 len = table->maxlen;
1249 if(copy_to_user(oldval, table->data, len))
1250 return -EFAULT;
1251 if(put_user(len, oldlenp))
1252 return -EFAULT;
1253 }
1254 }
1255 if (newval && newlen) {
1256 len = newlen;
1257 if (len > table->maxlen)
1258 len = table->maxlen;
1259 if(copy_from_user(table->data, newval, len))
1260 return -EFAULT;
1261 }
1262 }
1263 return 0;
1264}
b89a8171 1265#endif /* CONFIG_SYSCTL_SYSCALL */
1da177e4 1266
d912b0cc
EB		 1267static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1268{
1269 for (; table->ctl_name || table->procname; table++) {
1270 table->parent = parent;
1271 if (table->child)
1272 sysctl_set_parent(table, table->child);
1273 }
1274}
1275
1276static __init int sysctl_init(void)
1277{
1278 sysctl_set_parent(NULL, root_table);
1279 return 0;
1280}
1281
1282core_initcall(sysctl_init);
1283
1da177e4
LT		 1284/**
1285 * register_sysctl_table - register a sysctl hierarchy
1286 * @table: the top-level table structure
1da177e4
LT		 1287 *
1288 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1289 * array. An entry with a ctl_name of 0 terminates the table.
1290 *
1291 * The members of the &ctl_table structure are used as follows:
1292 *
1293 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1294 * must be unique within that level of sysctl
1295 *
1296 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1297 * enter a sysctl file
1298 *
1299 * data - a pointer to data for use by proc_handler
1300 *
1301 * maxlen - the maximum size in bytes of the data
1302 *
1303 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1304 *
1305 * child - a pointer to the child sysctl table if this entry is a directory, or
1306 * %NULL.
1307 *
1308 * proc_handler - the text handler routine (described below)
1309 *
1310 * strategy - the strategy routine (described below)
1311 *
1312 * de - for internal use by the sysctl routines
1313 *
1314 * extra1, extra2 - extra pointers usable by the proc handler routines
1315 *
1316 * Leaf nodes in the sysctl tree will be represented by a single file
1317 * under /proc; non-leaf nodes will be represented by directories.
1318 *
1319 * sysctl(2) can automatically manage read and write requests through
1320 * the sysctl table. The data and maxlen fields of the ctl_table
1321 * struct enable minimal validation of the values being written to be
1322 * performed, and the mode field allows minimal authentication.
1323 *
1324 * More sophisticated management can be enabled by the provision of a
1325 * strategy routine with the table entry. This will be called before
1326 * any automatic read or write of the data is performed.
1327 *
1328 * The strategy routine may return
1329 *
1330 * < 0 - Error occurred (error is passed to user process)
1331 *
1332 * 0 - OK - proceed with automatic read or write.
1333 *
1334 * > 0 - OK - read or write has been done by the strategy routine, so
1335 * return immediately.
1336 *
1337 * There must be a proc_handler routine for any terminal nodes
1338 * mirrored under /proc/sys (non-terminals are handled by a built-in
1339 * directory handler). Several default handlers are available to
1340 * cover common cases -
1341 *
1342 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1343 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1344 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1345 *
1346 * It is the handler's job to read the input buffer from user memory
1347 * and process it. The handler should return 0 on success.
1348 *
1349 * This routine returns %NULL on a failure to register, and a pointer
1350 * to the table header on success.
1351 */
0b4d4147 1352struct ctl_table_header *register_sysctl_table(ctl_table * table)
1da177e4
LT		 1353{
1354 struct ctl_table_header *tmp;
1355 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1356 if (!tmp)
1357 return NULL;
1358 tmp->ctl_table = table;
1359 INIT_LIST_HEAD(&tmp->ctl_entry);
330d57fb
AV		 1360 tmp->used = 0;
1361 tmp->unregistering = NULL;
d912b0cc 1362 sysctl_set_parent(NULL, table);
330d57fb 1363 spin_lock(&sysctl_lock);
0b4d4147 1364 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
330d57fb 1365 spin_unlock(&sysctl_lock);
1da177e4
LT		 1366 return tmp;
1367}
1368
1369/**
1370 * unregister_sysctl_table - unregister a sysctl table hierarchy
1371 * @header: the header returned from register_sysctl_table
1372 *
1373 * Unregisters the sysctl table and all children. proc entries may not
1374 * actually be removed until they are no longer used by anyone.
1375 */
1376void unregister_sysctl_table(struct ctl_table_header * header)
1377{
330d57fb
AV		 1378 might_sleep();
1379 spin_lock(&sysctl_lock);
1380 start_unregistering(header);
330d57fb 1381 spin_unlock(&sysctl_lock);
1da177e4
LT		 1382 kfree(header);
1383}
1384
b89a8171 1385#else /* !CONFIG_SYSCTL */
93a6fefe 1386struct ctl_table_header *register_sysctl_table(ctl_table * table)
b89a8171
EB		 1387{
1388 return NULL;
1389}
1390
1391void unregister_sysctl_table(struct ctl_table_header * table)
1392{
1393}
1394
1395#endif /* CONFIG_SYSCTL */
1396
1da177e4
LT		 1397/*
1398 * /proc/sys support
1399 */
1400
b89a8171 1401#ifdef CONFIG_PROC_SYSCTL
1da177e4 1402
b1ba4ddd
AB		 1403static int _proc_do_string(void* data, int maxlen, int write,
1404 struct file *filp, void __user *buffer,
1405 size_t *lenp, loff_t *ppos)
1da177e4
LT		 1406{
1407 size_t len;
1408 char __user *p;
1409 char c;
8d060877
ON		 1410
1411 if (!data || !maxlen || !*lenp) {
1da177e4
LT		 1412 *lenp = 0;
1413 return 0;
1414 }
8d060877 1415
1da177e4
LT		 1416 if (write) {
1417 len = 0;
1418 p = buffer;
1419 while (len < *lenp) {
1420 if (get_user(c, p++))
1421 return -EFAULT;
1422 if (c == 0 || c == '\n')
1423 break;
1424 len++;
1425 }
f5dd3d6f
SV		 1426 if (len >= maxlen)
1427 len = maxlen-1;
1428 if(copy_from_user(data, buffer, len))
1da177e4 1429 return -EFAULT;
f5dd3d6f 1430 ((char *) data)[len] = 0;
1da177e4
LT		 1431 *ppos += *lenp;
1432 } else {
f5dd3d6f
SV		 1433 len = strlen(data);
1434 if (len > maxlen)
1435 len = maxlen;
8d060877
ON		 1436
1437 if (*ppos > len) {
1438 *lenp = 0;
1439 return 0;
1440 }
1441
1442 data += *ppos;
1443 len -= *ppos;
1444
1da177e4
LT		 1445 if (len > *lenp)
1446 len = *lenp;
1447 if (len)
f5dd3d6f 1448 if(copy_to_user(buffer, data, len))
1da177e4
LT		 1449 return -EFAULT;
1450 if (len < *lenp) {
1451 if(put_user('\n', ((char __user *) buffer) + len))
1452 return -EFAULT;
1453 len++;
1454 }
1455 *lenp = len;
1456 *ppos += len;
1457 }
1458 return 0;
1459}
1460
f5dd3d6f
SV		 1461/**
1462 * proc_dostring - read a string sysctl
1463 * @table: the sysctl table
1464 * @write: %TRUE if this is a write to the sysctl file
1465 * @filp: the file structure
1466 * @buffer: the user buffer
1467 * @lenp: the size of the user buffer
1468 * @ppos: file position
1469 *
1470 * Reads/writes a string from/to the user buffer. If the kernel
1471 * buffer provided is not large enough to hold the string, the
1472 * string is truncated. The copied string is %NULL-terminated.
1473 * If the string is being read by the user process, it is copied
1474 * and a newline '\n' is added. It is truncated if the buffer is
1475 * not large enough.
1476 *
1477 * Returns 0 on success.
1478 */
1479int proc_dostring(ctl_table *table, int write, struct file *filp,
1480 void __user *buffer, size_t *lenp, loff_t *ppos)
1481{
1482 return _proc_do_string(table->data, table->maxlen, write, filp,
1483 buffer, lenp, ppos);
1484}
1485
1da177e4
LT		 1486
1487static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1488 int *valp,
1489 int write, void *data)
1490{
1491 if (write) {
1492 *valp = *negp ? -*lvalp : *lvalp;
1493 } else {
1494 int val = *valp;
1495 if (val < 0) {
1496 *negp = -1;
1497 *lvalp = (unsigned long)-val;
1498 } else {
1499 *negp = 0;
1500 *lvalp = (unsigned long)val;
1501 }
1502 }
1503 return 0;
1504}
1505
fcfbd547
KK		 1506static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1507 int write, struct file *filp, void __user *buffer,
1508 size_t *lenp, loff_t *ppos,
1da177e4
LT		 1509 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1510 int write, void *data),
1511 void *data)
1512{
1513#define TMPBUFLEN 21
1514 int *i, vleft, first=1, neg, val;
1515 unsigned long lval;
1516 size_t left, len;
1517
1518 char buf[TMPBUFLEN], *p;
1519 char __user *s = buffer;
1520
fcfbd547 1521 if (!tbl_data || !table->maxlen || !*lenp ||
1da177e4
LT		 1522 (*ppos && !write)) {
1523 *lenp = 0;
1524 return 0;
1525 }
1526
fcfbd547 1527 i = (int *) tbl_data;
1da177e4
LT		 1528 vleft = table->maxlen / sizeof(*i);
1529 left = *lenp;
1530
1531 if (!conv)
1532 conv = do_proc_dointvec_conv;
1533
1534 for (; left && vleft--; i++, first=0) {
1535 if (write) {
1536 while (left) {
1537 char c;
1538 if (get_user(c, s))
1539 return -EFAULT;
1540 if (!isspace(c))
1541 break;
1542 left--;
1543 s++;
1544 }
1545 if (!left)
1546 break;
1547 neg = 0;
1548 len = left;
1549 if (len > sizeof(buf) - 1)
1550 len = sizeof(buf) - 1;
1551 if (copy_from_user(buf, s, len))
1552 return -EFAULT;
1553 buf[len] = 0;
1554 p = buf;
1555 if (*p == '-' && left > 1) {
1556 neg = 1;
bd9b0bac 1557 p++;
1da177e4
LT		 1558 }
1559 if (*p < '0' || *p > '9')
1560 break;
1561
1562 lval = simple_strtoul(p, &p, 0);
1563
1564 len = p-buf;
1565 if ((len < left) && *p && !isspace(*p))
1566 break;
1567 if (neg)
1568 val = -val;
1569 s += len;
1570 left -= len;
1571
1572 if (conv(&neg, &lval, i, 1, data))
1573 break;
1574 } else {
1575 p = buf;
1576 if (!first)
1577 *p++ = '\t';
1578
1579 if (conv(&neg, &lval, i, 0, data))
1580 break;
1581
1582 sprintf(p, "%s%lu", neg ? "-" : "", lval);
1583 len = strlen(buf);
1584 if (len > left)
1585 len = left;
1586 if(copy_to_user(s, buf, len))
1587 return -EFAULT;
1588 left -= len;
1589 s += len;
1590 }
1591 }
1592
1593 if (!write && !first && left) {
1594 if(put_user('\n', s))
1595 return -EFAULT;
1596 left--, s++;
1597 }
1598 if (write) {
1599 while (left) {
1600 char c;
1601 if (get_user(c, s++))
1602 return -EFAULT;
1603 if (!isspace(c))
1604 break;
1605 left--;
1606 }
1607 }
1608 if (write && first)
1609 return -EINVAL;
1610 *lenp -= left;
1611 *ppos += *lenp;
1612 return 0;
1613#undef TMPBUFLEN
1614}
1615
fcfbd547
KK		 1616static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1617 void __user *buffer, size_t *lenp, loff_t *ppos,
1618 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1619 int write, void *data),
1620 void *data)
1621{
1622 return __do_proc_dointvec(table->data, table, write, filp,
1623 buffer, lenp, ppos, conv, data);
1624}
1625
1da177e4
LT		 1626/**
1627 * proc_dointvec - read a vector of integers
1628 * @table: the sysctl table
1629 * @write: %TRUE if this is a write to the sysctl file
1630 * @filp: the file structure
1631 * @buffer: the user buffer
1632 * @lenp: the size of the user buffer
1633 * @ppos: file position
1634 *
1635 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1636 * values from/to the user buffer, treated as an ASCII string.
1637 *
1638 * Returns 0 on success.
1639 */
1640int proc_dointvec(ctl_table *table, int write, struct file *filp,
1641 void __user *buffer, size_t *lenp, loff_t *ppos)
1642{
1643 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1644 NULL,NULL);
1645}
1646
1647#define OP_SET 0
1648#define OP_AND 1
34f5a398 1649#define OP_OR 2
1da177e4
LT		 1650
1651static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1652 int *valp,
1653 int write, void *data)
1654{
1655 int op = *(int *)data;
1656 if (write) {
1657 int val = *negp ? -*lvalp : *lvalp;
1658 switch(op) {
1659 case OP_SET: *valp = val; break;
1660 case OP_AND: *valp &= val; break;
34f5a398 1661 case OP_OR: *valp |= val; break;
1da177e4
LT		 1662 }
1663 } else {
1664 int val = *valp;
1665 if (val < 0) {
1666 *negp = -1;
1667 *lvalp = (unsigned long)-val;
1668 } else {
1669 *negp = 0;
1670 *lvalp = (unsigned long)val;
1671 }
1672 }
1673 return 0;
1674}
1675
1676/*
1677 * init may raise the set.
1678 */
1679
1680int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1681 void __user *buffer, size_t *lenp, loff_t *ppos)
1682{
1683 int op;
1684
6ff1b442 1685 if (write && !capable(CAP_SYS_MODULE)) {
1da177e4
LT		 1686 return -EPERM;
1687 }
1688
f400e198 1689 op = is_init(current) ? OP_SET : OP_AND;
1da177e4
LT		 1690 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1691 do_proc_dointvec_bset_conv,&op);
1692}
1693
34f5a398
TT		 1694/*
1695 * Taint values can only be increased
1696 */
1697static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1698 void __user *buffer, size_t *lenp, loff_t *ppos)
1699{
1700 int op;
1701
91fcd412 1702 if (write && !capable(CAP_SYS_ADMIN))
34f5a398
TT		 1703 return -EPERM;
1704
1705 op = OP_OR;
1706 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1707 do_proc_dointvec_bset_conv,&op);
1708}
1709
1da177e4
LT		 1710struct do_proc_dointvec_minmax_conv_param {
1711 int *min;
1712 int *max;
1713};
1714
1715static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1716 int *valp,
1717 int write, void *data)
1718{
1719 struct do_proc_dointvec_minmax_conv_param *param = data;
1720 if (write) {
1721 int val = *negp ? -*lvalp : *lvalp;
1722 if ((param->min && *param->min > val) ||
1723 (param->max && *param->max < val))
1724 return -EINVAL;
1725 *valp = val;
1726 } else {
1727 int val = *valp;
1728 if (val < 0) {
1729 *negp = -1;
1730 *lvalp = (unsigned long)-val;
1731 } else {
1732 *negp = 0;
1733 *lvalp = (unsigned long)val;
1734 }
1735 }
1736 return 0;
1737}
1738
1739/**
1740 * proc_dointvec_minmax - read a vector of integers with min/max values
1741 * @table: the sysctl table
1742 * @write: %TRUE if this is a write to the sysctl file
1743 * @filp: the file structure
1744 * @buffer: the user buffer
1745 * @lenp: the size of the user buffer
1746 * @ppos: file position
1747 *
1748 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1749 * values from/to the user buffer, treated as an ASCII string.
1750 *
1751 * This routine will ensure the values are within the range specified by
1752 * table->extra1 (min) and table->extra2 (max).
1753 *
1754 * Returns 0 on success.
1755 */
1756int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1757 void __user *buffer, size_t *lenp, loff_t *ppos)
1758{
1759 struct do_proc_dointvec_minmax_conv_param param = {
1760 .min = (int *) table->extra1,
1761 .max = (int *) table->extra2,
1762 };
1763 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1764 do_proc_dointvec_minmax_conv, &param);
1765}
1766
fcfbd547 1767static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1da177e4
LT		 1768 struct file *filp,
1769 void __user *buffer,
1770 size_t *lenp, loff_t *ppos,
1771 unsigned long convmul,
1772 unsigned long convdiv)
1773{
1774#define TMPBUFLEN 21
1775 unsigned long *i, *min, *max, val;
1776 int vleft, first=1, neg;
1777 size_t len, left;
1778 char buf[TMPBUFLEN], *p;
1779 char __user *s = buffer;
1780
fcfbd547 1781 if (!data || !table->maxlen || !*lenp ||
1da177e4
LT		 1782 (*ppos && !write)) {
1783 *lenp = 0;
1784 return 0;
1785 }
1786
fcfbd547 1787 i = (unsigned long *) data;
1da177e4
LT		 1788 min = (unsigned long *) table->extra1;
1789 max = (unsigned long *) table->extra2;
1790 vleft = table->maxlen / sizeof(unsigned long);
1791 left = *lenp;
1792
1793 for (; left && vleft--; i++, min++, max++, first=0) {
1794 if (write) {
1795 while (left) {
1796 char c;
1797 if (get_user(c, s))
1798 return -EFAULT;
1799 if (!isspace(c))
1800 break;
1801 left--;
1802 s++;
1803 }
1804 if (!left)
1805 break;
1806 neg = 0;
1807 len = left;
1808 if (len > TMPBUFLEN-1)
1809 len = TMPBUFLEN-1;
1810 if (copy_from_user(buf, s, len))
1811 return -EFAULT;
1812 buf[len] = 0;
1813 p = buf;
1814 if (*p == '-' && left > 1) {
1815 neg = 1;
bd9b0bac 1816 p++;
1da177e4
LT		 1817 }
1818 if (*p < '0' || *p > '9')
1819 break;
1820 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1821 len = p-buf;
1822 if ((len < left) && *p && !isspace(*p))
1823 break;
1824 if (neg)
1825 val = -val;
1826 s += len;
1827 left -= len;
1828
1829 if(neg)
1830 continue;
1831 if ((min && val < *min) || (max && val > *max))
1832 continue;
1833 *i = val;
1834 } else {
1835 p = buf;
1836 if (!first)
1837 *p++ = '\t';
1838 sprintf(p, "%lu", convdiv * (*i) / convmul);
1839 len = strlen(buf);
1840 if (len > left)
1841 len = left;
1842 if(copy_to_user(s, buf, len))
1843 return -EFAULT;
1844 left -= len;
1845 s += len;
1846 }
1847 }
1848
1849 if (!write && !first && left) {
1850 if(put_user('\n', s))
1851 return -EFAULT;
1852 left--, s++;
1853 }
1854 if (write) {
1855 while (left) {
1856 char c;
1857 if (get_user(c, s++))
1858 return -EFAULT;
1859 if (!isspace(c))
1860 break;
1861 left--;
1862 }
1863 }
1864 if (write && first)
1865 return -EINVAL;
1866 *lenp -= left;
1867 *ppos += *lenp;
1868 return 0;
1869#undef TMPBUFLEN
1870}
1871
fcfbd547
KK		 1872static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1873 struct file *filp,
1874 void __user *buffer,
1875 size_t *lenp, loff_t *ppos,
1876 unsigned long convmul,
1877 unsigned long convdiv)
1878{
1879 return __do_proc_doulongvec_minmax(table->data, table, write,
1880 filp, buffer, lenp, ppos, convmul, convdiv);
1881}
1882
1da177e4
LT		 1883/**
1884 * proc_doulongvec_minmax - read a vector of long integers with min/max values
1885 * @table: the sysctl table
1886 * @write: %TRUE if this is a write to the sysctl file
1887 * @filp: the file structure
1888 * @buffer: the user buffer
1889 * @lenp: the size of the user buffer
1890 * @ppos: file position
1891 *
1892 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1893 * values from/to the user buffer, treated as an ASCII string.
1894 *
1895 * This routine will ensure the values are within the range specified by
1896 * table->extra1 (min) and table->extra2 (max).
1897 *
1898 * Returns 0 on success.
1899 */
1900int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
1901 void __user *buffer, size_t *lenp, loff_t *ppos)
1902{
1903 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
1904}
1905
1906/**
1907 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
1908 * @table: the sysctl table
1909 * @write: %TRUE if this is a write to the sysctl file
1910 * @filp: the file structure
1911 * @buffer: the user buffer
1912 * @lenp: the size of the user buffer
1913 * @ppos: file position
1914 *
1915 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1916 * values from/to the user buffer, treated as an ASCII string. The values
1917 * are treated as milliseconds, and converted to jiffies when they are stored.
1918 *
1919 * This routine will ensure the values are within the range specified by
1920 * table->extra1 (min) and table->extra2 (max).
1921 *
1922 * Returns 0 on success.
1923 */
1924int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
1925 struct file *filp,
1926 void __user *buffer,
1927 size_t *lenp, loff_t *ppos)
1928{
1929 return do_proc_doulongvec_minmax(table, write, filp, buffer,
1930 lenp, ppos, HZ, 1000l);
1931}
1932
1933
1934static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
1935 int *valp,
1936 int write, void *data)
1937{
1938 if (write) {
cba9f33d
BS		 1939 if (*lvalp > LONG_MAX / HZ)
1940 return 1;
1da177e4
LT		 1941 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
1942 } else {
1943 int val = *valp;
1944 unsigned long lval;
1945 if (val < 0) {
1946 *negp = -1;
1947 lval = (unsigned long)-val;
1948 } else {
1949 *negp = 0;
1950 lval = (unsigned long)val;
1951 }
1952 *lvalp = lval / HZ;
1953 }
1954 return 0;
1955}
1956
1957static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
1958 int *valp,
1959 int write, void *data)
1960{
1961 if (write) {
cba9f33d
BS		 1962 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
1963 return 1;
1da177e4
LT		 1964 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
1965 } else {
1966 int val = *valp;
1967 unsigned long lval;
1968 if (val < 0) {
1969 *negp = -1;
1970 lval = (unsigned long)-val;
1971 } else {
1972 *negp = 0;
1973 lval = (unsigned long)val;
1974 }
1975 *lvalp = jiffies_to_clock_t(lval);
1976 }
1977 return 0;
1978}
1979
1980static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
1981 int *valp,
1982 int write, void *data)
1983{
1984 if (write) {
1985 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
1986 } else {
1987 int val = *valp;
1988 unsigned long lval;
1989 if (val < 0) {
1990 *negp = -1;
1991 lval = (unsigned long)-val;
1992 } else {
1993 *negp = 0;
1994 lval = (unsigned long)val;
1995 }
1996 *lvalp = jiffies_to_msecs(lval);
1997 }
1998 return 0;
1999}
2000
2001/**
2002 * proc_dointvec_jiffies - read a vector of integers as seconds
2003 * @table: the sysctl table
2004 * @write: %TRUE if this is a write to the sysctl file
2005 * @filp: the file structure
2006 * @buffer: the user buffer
2007 * @lenp: the size of the user buffer
2008 * @ppos: file position
2009 *
2010 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2011 * values from/to the user buffer, treated as an ASCII string.
2012 * The values read are assumed to be in seconds, and are converted into
2013 * jiffies.
2014 *
2015 * Returns 0 on success.
2016 */
2017int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2018 void __user *buffer, size_t *lenp, loff_t *ppos)
2019{
2020 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2021 do_proc_dointvec_jiffies_conv,NULL);
2022}
2023
2024/**
2025 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2026 * @table: the sysctl table
2027 * @write: %TRUE if this is a write to the sysctl file
2028 * @filp: the file structure
2029 * @buffer: the user buffer
2030 * @lenp: the size of the user buffer
1e5d5331 2031 * @ppos: pointer to the file position
1da177e4
LT		 2032 *
2033 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2034 * values from/to the user buffer, treated as an ASCII string.
2035 * The values read are assumed to be in 1/USER_HZ seconds, and
2036 * are converted into jiffies.
2037 *
2038 * Returns 0 on success.
2039 */
2040int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2041 void __user *buffer, size_t *lenp, loff_t *ppos)
2042{
2043 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2044 do_proc_dointvec_userhz_jiffies_conv,NULL);
2045}
2046
2047/**
2048 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2049 * @table: the sysctl table
2050 * @write: %TRUE if this is a write to the sysctl file
2051 * @filp: the file structure
2052 * @buffer: the user buffer
2053 * @lenp: the size of the user buffer
67be2dd1
MW		 2054 * @ppos: file position
2055 * @ppos: the current position in the file
1da177e4
LT		 2056 *
2057 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2058 * values from/to the user buffer, treated as an ASCII string.
2059 * The values read are assumed to be in 1/1000 seconds, and
2060 * are converted into jiffies.
2061 *
2062 * Returns 0 on success.
2063 */
2064int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2065 void __user *buffer, size_t *lenp, loff_t *ppos)
2066{
2067 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2068 do_proc_dointvec_ms_jiffies_conv, NULL);
2069}
2070
9ec52099
CLG		 2071static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2072 void __user *buffer, size_t *lenp, loff_t *ppos)
2073{
2074 struct pid *new_pid;
2075 pid_t tmp;
2076 int r;
2077
2078 tmp = pid_nr(cad_pid);
2079
2080 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2081 lenp, ppos, NULL, NULL);
2082 if (r || !write)
2083 return r;
2084
2085 new_pid = find_get_pid(tmp);
2086 if (!new_pid)
2087 return -ESRCH;
2088
2089 put_pid(xchg(&cad_pid, new_pid));
2090 return 0;
2091}
2092
1da177e4
LT		 2093#else /* CONFIG_PROC_FS */
2094
2095int proc_dostring(ctl_table *table, int write, struct file *filp,
2096 void __user *buffer, size_t *lenp, loff_t *ppos)
2097{
2098 return -ENOSYS;
2099}
2100
1da177e4
LT		 2101int proc_dointvec(ctl_table *table, int write, struct file *filp,
2102 void __user *buffer, size_t *lenp, loff_t *ppos)
2103{
2104 return -ENOSYS;
2105}
2106
2107int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2108 void __user *buffer, size_t *lenp, loff_t *ppos)
2109{
2110 return -ENOSYS;
2111}
2112
2113int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2114 void __user *buffer, size_t *lenp, loff_t *ppos)
2115{
2116 return -ENOSYS;
2117}
2118
2119int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2120 void __user *buffer, size_t *lenp, loff_t *ppos)
2121{
2122 return -ENOSYS;
2123}
2124
2125int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2126 void __user *buffer, size_t *lenp, loff_t *ppos)
2127{
2128 return -ENOSYS;
2129}
2130
2131int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2132 void __user *buffer, size_t *lenp, loff_t *ppos)
2133{
2134 return -ENOSYS;
2135}
2136
2137int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2138 void __user *buffer, size_t *lenp, loff_t *ppos)
2139{
2140 return -ENOSYS;
2141}
2142
2143int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2144 struct file *filp,
2145 void __user *buffer,
2146 size_t *lenp, loff_t *ppos)
2147{
2148 return -ENOSYS;
2149}
2150
2151
2152#endif /* CONFIG_PROC_FS */
2153
2154
b89a8171 2155#ifdef CONFIG_SYSCTL_SYSCALL
1da177e4
LT		 2156/*
2157 * General sysctl support routines
2158 */
2159
2160/* The generic string strategy routine: */
2161int sysctl_string(ctl_table *table, int __user *name, int nlen,
2162 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 2163 void __user *newval, size_t newlen)
1da177e4 2164{
1da177e4
LT		 2165 if (!table->data || !table->maxlen)
2166 return -ENOTDIR;
2167
2168 if (oldval && oldlenp) {
de9e007d
LT		 2169 size_t bufsize;
2170 if (get_user(bufsize, oldlenp))
1da177e4 2171 return -EFAULT;
de9e007d
LT		 2172 if (bufsize) {
2173 size_t len = strlen(table->data), copied;
2174
2175 /* This shouldn't trigger for a well-formed sysctl */
2176 if (len > table->maxlen)
1da177e4 2177 len = table->maxlen;
de9e007d
LT		 2178
2179 /* Copy up to a max of bufsize-1 bytes of the string */
2180 copied = (len >= bufsize) ? bufsize - 1 : len;
2181
2182 if (copy_to_user(oldval, table->data, copied) ||
2183 put_user(0, (char __user *)(oldval + copied)))
1da177e4 2184 return -EFAULT;
de9e007d 2185 if (put_user(len, oldlenp))
1da177e4
LT		 2186 return -EFAULT;
2187 }
2188 }
2189 if (newval && newlen) {
de9e007d 2190 size_t len = newlen;
1da177e4
LT		 2191 if (len > table->maxlen)
2192 len = table->maxlen;
2193 if(copy_from_user(table->data, newval, len))
2194 return -EFAULT;
2195 if (len == table->maxlen)
2196 len--;
2197 ((char *) table->data)[len] = 0;
2198 }
82c9df82 2199 return 1;
1da177e4
LT		 2200}
2201
2202/*
2203 * This function makes sure that all of the integers in the vector
2204 * are between the minimum and maximum values given in the arrays
2205 * table->extra1 and table->extra2, respectively.
2206 */
2207int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2208 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 2209 void __user *newval, size_t newlen)
1da177e4
LT		 2210{
2211
2212 if (newval && newlen) {
2213 int __user *vec = (int __user *) newval;
2214 int *min = (int *) table->extra1;
2215 int *max = (int *) table->extra2;
2216 size_t length;
2217 int i;
2218
2219 if (newlen % sizeof(int) != 0)
2220 return -EINVAL;
2221
2222 if (!table->extra1 && !table->extra2)
2223 return 0;
2224
2225 if (newlen > table->maxlen)
2226 newlen = table->maxlen;
2227 length = newlen / sizeof(int);
2228
2229 for (i = 0; i < length; i++) {
2230 int value;
2231 if (get_user(value, vec + i))
2232 return -EFAULT;
2233 if (min && value < min[i])
2234 return -EINVAL;
2235 if (max && value > max[i])
2236 return -EINVAL;
2237 }
2238 }
2239 return 0;
2240}
2241
2242/* Strategy function to convert jiffies to seconds */
2243int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2244 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 2245 void __user *newval, size_t newlen)
1da177e4 2246{
3ee75ac3 2247 if (oldval && oldlenp) {
1da177e4 2248 size_t olen;
3ee75ac3
AD		 2249
2250 if (get_user(olen, oldlenp))
2251 return -EFAULT;
2252 if (olen) {
2253 int val;
2254
2255 if (olen < sizeof(int))
2256 return -EINVAL;
2257
2258 val = *(int *)(table->data) / HZ;
2259 if (put_user(val, (int __user *)oldval))
2260 return -EFAULT;
2261 if (put_user(sizeof(int), oldlenp))
1da177e4 2262 return -EFAULT;
1da177e4 2263 }
1da177e4
LT		 2264 }
2265 if (newval && newlen) {
2266 int new;
2267 if (newlen != sizeof(int))
2268 return -EINVAL;
2269 if (get_user(new, (int __user *)newval))
2270 return -EFAULT;
2271 *(int *)(table->data) = new*HZ;
2272 }
2273 return 1;
2274}
2275
2276/* Strategy function to convert jiffies to seconds */
2277int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2278 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 2279 void __user *newval, size_t newlen)
1da177e4 2280{
3ee75ac3 2281 if (oldval && oldlenp) {
1da177e4 2282 size_t olen;
3ee75ac3
AD		 2283
2284 if (get_user(olen, oldlenp))
2285 return -EFAULT;
2286 if (olen) {
2287 int val;
2288
2289 if (olen < sizeof(int))
2290 return -EINVAL;
2291
2292 val = jiffies_to_msecs(*(int *)(table->data));
2293 if (put_user(val, (int __user *)oldval))
2294 return -EFAULT;
2295 if (put_user(sizeof(int), oldlenp))
1da177e4 2296 return -EFAULT;
1da177e4 2297 }
1da177e4
LT		 2298 }
2299 if (newval && newlen) {
2300 int new;
2301 if (newlen != sizeof(int))
2302 return -EINVAL;
2303 if (get_user(new, (int __user *)newval))
2304 return -EFAULT;
2305 *(int *)(table->data) = msecs_to_jiffies(new);
2306 }
2307 return 1;
2308}
2309
c4b8b769 2310
c4b8b769 2311
b89a8171 2312#else /* CONFIG_SYSCTL_SYSCALL */
1da177e4
LT		 2313
2314
2315asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2316{
b89a8171 2317 static int msg_count;
0e009be8
EB		 2318 struct __sysctl_args tmp;
2319 int name[CTL_MAXNAME];
2320 int i;
2321
2322 /* Read in the sysctl name for better debug message logging */
2323 if (copy_from_user(&tmp, args, sizeof(tmp)))
2324 return -EFAULT;
2325 if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2326 return -ENOTDIR;
2327 for (i = 0; i < tmp.nlen; i++)
2328 if (get_user(name[i], tmp.name + i))
2329 return -EFAULT;
2330
2331 /* Ignore accesses to kernel.version */
2332 if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2333 goto out;
b89a8171
EB		 2334
2335 if (msg_count < 5) {
2336 msg_count++;
2337 printk(KERN_INFO
2338 "warning: process `%s' used the removed sysctl "
0e009be8
EB		 2339 "system call with ", current->comm);
2340 for (i = 0; i < tmp.nlen; i++)
2341 printk("%d.", name[i]);
2342 printk("\n");
b89a8171 2343 }
0e009be8 2344out:
1da177e4
LT		 2345 return -ENOSYS;
2346}
2347
2348int sysctl_string(ctl_table *table, int __user *name, int nlen,
2349 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 2350 void __user *newval, size_t newlen)
1da177e4
LT		 2351{
2352 return -ENOSYS;
2353}
2354
2355int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2356 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 2357 void __user *newval, size_t newlen)
1da177e4
LT		 2358{
2359 return -ENOSYS;
2360}
2361
2362int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2363 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 2364 void __user *newval, size_t newlen)
1da177e4
LT		 2365{
2366 return -ENOSYS;
2367}
2368
2369int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2370 void __user *oldval, size_t __user *oldlenp,
1f29bcd7 2371 void __user *newval, size_t newlen)
1da177e4
LT		 2372{
2373 return -ENOSYS;
2374}
2375
b89a8171 2376#endif /* CONFIG_SYSCTL_SYSCALL */
1da177e4
LT		 2377
2378/*
2379 * No sense putting this after each symbol definition, twice,
2380 * exception granted :-)
2381 */
2382EXPORT_SYMBOL(proc_dointvec);
2383EXPORT_SYMBOL(proc_dointvec_jiffies);
2384EXPORT_SYMBOL(proc_dointvec_minmax);
2385EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2386EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2387EXPORT_SYMBOL(proc_dostring);
2388EXPORT_SYMBOL(proc_doulongvec_minmax);
2389EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2390EXPORT_SYMBOL(register_sysctl_table);
2391EXPORT_SYMBOL(sysctl_intvec);
2392EXPORT_SYMBOL(sysctl_jiffies);
2393EXPORT_SYMBOL(sysctl_ms_jiffies);
2394EXPORT_SYMBOL(sysctl_string);
2395EXPORT_SYMBOL(unregister_sysctl_table);
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