block: add blk-iopoll, a NAPI like approach for block devices
[linux-2.6.git] / kernel / sysctl.c
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
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/ctype.h>
29 #include <linux/utsname.h>
30 #include <linux/kmemcheck.h>
31 #include <linux/smp_lock.h>
32 #include <linux/fs.h>
33 #include <linux/init.h>
34 #include <linux/kernel.h>
35 #include <linux/kobject.h>
36 #include <linux/net.h>
37 #include <linux/sysrq.h>
38 #include <linux/highuid.h>
39 #include <linux/writeback.h>
40 #include <linux/hugetlb.h>
41 #include <linux/initrd.h>
42 #include <linux/key.h>
43 #include <linux/times.h>
44 #include <linux/limits.h>
45 #include <linux/dcache.h>
46 #include <linux/syscalls.h>
47 #include <linux/vmstat.h>
48 #include <linux/nfs_fs.h>
49 #include <linux/acpi.h>
50 #include <linux/reboot.h>
51 #include <linux/ftrace.h>
52 #include <linux/security.h>
53 #include <linux/slow-work.h>
54 #include <linux/perf_counter.h>
55
56 #include <asm/uaccess.h>
57 #include <asm/processor.h>
58
59 #ifdef CONFIG_X86
60 #include <asm/nmi.h>
61 #include <asm/stacktrace.h>
62 #include <asm/io.h>
63 #endif
64
65 static int deprecated_sysctl_warning(struct __sysctl_args *args);
66
67 #if defined(CONFIG_SYSCTL)
68
69 /* External variables not in a header file. */
70 extern int C_A_D;
71 extern int print_fatal_signals;
72 extern int sysctl_overcommit_memory;
73 extern int sysctl_overcommit_ratio;
74 extern int sysctl_panic_on_oom;
75 extern int sysctl_oom_kill_allocating_task;
76 extern int sysctl_oom_dump_tasks;
77 extern int max_threads;
78 extern int core_uses_pid;
79 extern int suid_dumpable;
80 extern char core_pattern[];
81 extern int pid_max;
82 extern int min_free_kbytes;
83 extern int pid_max_min, pid_max_max;
84 extern int sysctl_drop_caches;
85 extern int percpu_pagelist_fraction;
86 extern int compat_log;
87 extern int latencytop_enabled;
88 extern int sysctl_nr_open_min, sysctl_nr_open_max;
89 #ifndef CONFIG_MMU
90 extern int sysctl_nr_trim_pages;
91 #endif
92 #ifdef CONFIG_RCU_TORTURE_TEST
93 extern int rcutorture_runnable;
94 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
95 extern int blk_iopoll_enabled;
96
97 /* Constants used for minimum and  maximum */
98 #ifdef CONFIG_DETECT_SOFTLOCKUP
99 static int sixty = 60;
100 static int neg_one = -1;
101 #endif
102
103 static int zero;
104 static int __maybe_unused one = 1;
105 static int __maybe_unused two = 2;
106 static unsigned long one_ul = 1;
107 static int one_hundred = 100;
108
109 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
110 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
111
112 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
113 static int maxolduid = 65535;
114 static int minolduid;
115 static int min_percpu_pagelist_fract = 8;
116
117 static int ngroups_max = NGROUPS_MAX;
118
119 #ifdef CONFIG_MODULES
120 extern char modprobe_path[];
121 extern int modules_disabled;
122 #endif
123 #ifdef CONFIG_CHR_DEV_SG
124 extern int sg_big_buff;
125 #endif
126
127 #ifdef CONFIG_SPARC
128 #include <asm/system.h>
129 #endif
130
131 #ifdef CONFIG_SPARC64
132 extern int sysctl_tsb_ratio;
133 #endif
134
135 #ifdef __hppa__
136 extern int pwrsw_enabled;
137 extern int unaligned_enabled;
138 #endif
139
140 #ifdef CONFIG_S390
141 #ifdef CONFIG_MATHEMU
142 extern int sysctl_ieee_emulation_warnings;
143 #endif
144 extern int sysctl_userprocess_debug;
145 extern int spin_retry;
146 #endif
147
148 #ifdef CONFIG_BSD_PROCESS_ACCT
149 extern int acct_parm[];
150 #endif
151
152 #ifdef CONFIG_IA64
153 extern int no_unaligned_warning;
154 extern int unaligned_dump_stack;
155 #endif
156
157 #ifdef CONFIG_RT_MUTEXES
158 extern int max_lock_depth;
159 #endif
160
161 #ifdef CONFIG_PROC_SYSCTL
162 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
163                   void __user *buffer, size_t *lenp, loff_t *ppos);
164 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
165                                void __user *buffer, size_t *lenp, loff_t *ppos);
166 #endif
167
168 static struct ctl_table root_table[];
169 static struct ctl_table_root sysctl_table_root;
170 static struct ctl_table_header root_table_header = {
171         .count = 1,
172         .ctl_table = root_table,
173         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
174         .root = &sysctl_table_root,
175         .set = &sysctl_table_root.default_set,
176 };
177 static struct ctl_table_root sysctl_table_root = {
178         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
179         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
180 };
181
182 static struct ctl_table kern_table[];
183 static struct ctl_table vm_table[];
184 static struct ctl_table fs_table[];
185 static struct ctl_table debug_table[];
186 static struct ctl_table dev_table[];
187 extern struct ctl_table random_table[];
188 #ifdef CONFIG_INOTIFY_USER
189 extern struct ctl_table inotify_table[];
190 #endif
191 #ifdef CONFIG_EPOLL
192 extern struct ctl_table epoll_table[];
193 #endif
194
195 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
196 int sysctl_legacy_va_layout;
197 #endif
198
199 extern int prove_locking;
200 extern int lock_stat;
201
202 /* The default sysctl tables: */
203
204 static struct ctl_table root_table[] = {
205         {
206                 .ctl_name       = CTL_KERN,
207                 .procname       = "kernel",
208                 .mode           = 0555,
209                 .child          = kern_table,
210         },
211         {
212                 .ctl_name       = CTL_VM,
213                 .procname       = "vm",
214                 .mode           = 0555,
215                 .child          = vm_table,
216         },
217         {
218                 .ctl_name       = CTL_FS,
219                 .procname       = "fs",
220                 .mode           = 0555,
221                 .child          = fs_table,
222         },
223         {
224                 .ctl_name       = CTL_DEBUG,
225                 .procname       = "debug",
226                 .mode           = 0555,
227                 .child          = debug_table,
228         },
229         {
230                 .ctl_name       = CTL_DEV,
231                 .procname       = "dev",
232                 .mode           = 0555,
233                 .child          = dev_table,
234         },
235 /*
236  * NOTE: do not add new entries to this table unless you have read
237  * Documentation/sysctl/ctl_unnumbered.txt
238  */
239         { .ctl_name = 0 }
240 };
241
242 #ifdef CONFIG_SCHED_DEBUG
243 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
244 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
245 static int min_wakeup_granularity_ns;                   /* 0 usecs */
246 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
247 #endif
248
249 static struct ctl_table kern_table[] = {
250 #ifdef CONFIG_SCHED_DEBUG
251         {
252                 .ctl_name       = CTL_UNNUMBERED,
253                 .procname       = "sched_min_granularity_ns",
254                 .data           = &sysctl_sched_min_granularity,
255                 .maxlen         = sizeof(unsigned int),
256                 .mode           = 0644,
257                 .proc_handler   = &sched_nr_latency_handler,
258                 .strategy       = &sysctl_intvec,
259                 .extra1         = &min_sched_granularity_ns,
260                 .extra2         = &max_sched_granularity_ns,
261         },
262         {
263                 .ctl_name       = CTL_UNNUMBERED,
264                 .procname       = "sched_latency_ns",
265                 .data           = &sysctl_sched_latency,
266                 .maxlen         = sizeof(unsigned int),
267                 .mode           = 0644,
268                 .proc_handler   = &sched_nr_latency_handler,
269                 .strategy       = &sysctl_intvec,
270                 .extra1         = &min_sched_granularity_ns,
271                 .extra2         = &max_sched_granularity_ns,
272         },
273         {
274                 .ctl_name       = CTL_UNNUMBERED,
275                 .procname       = "sched_wakeup_granularity_ns",
276                 .data           = &sysctl_sched_wakeup_granularity,
277                 .maxlen         = sizeof(unsigned int),
278                 .mode           = 0644,
279                 .proc_handler   = &proc_dointvec_minmax,
280                 .strategy       = &sysctl_intvec,
281                 .extra1         = &min_wakeup_granularity_ns,
282                 .extra2         = &max_wakeup_granularity_ns,
283         },
284         {
285                 .ctl_name       = CTL_UNNUMBERED,
286                 .procname       = "sched_shares_ratelimit",
287                 .data           = &sysctl_sched_shares_ratelimit,
288                 .maxlen         = sizeof(unsigned int),
289                 .mode           = 0644,
290                 .proc_handler   = &proc_dointvec,
291         },
292         {
293                 .ctl_name       = CTL_UNNUMBERED,
294                 .procname       = "sched_shares_thresh",
295                 .data           = &sysctl_sched_shares_thresh,
296                 .maxlen         = sizeof(unsigned int),
297                 .mode           = 0644,
298                 .proc_handler   = &proc_dointvec_minmax,
299                 .strategy       = &sysctl_intvec,
300                 .extra1         = &zero,
301         },
302         {
303                 .ctl_name       = CTL_UNNUMBERED,
304                 .procname       = "sched_child_runs_first",
305                 .data           = &sysctl_sched_child_runs_first,
306                 .maxlen         = sizeof(unsigned int),
307                 .mode           = 0644,
308                 .proc_handler   = &proc_dointvec,
309         },
310         {
311                 .ctl_name       = CTL_UNNUMBERED,
312                 .procname       = "sched_features",
313                 .data           = &sysctl_sched_features,
314                 .maxlen         = sizeof(unsigned int),
315                 .mode           = 0644,
316                 .proc_handler   = &proc_dointvec,
317         },
318         {
319                 .ctl_name       = CTL_UNNUMBERED,
320                 .procname       = "sched_migration_cost",
321                 .data           = &sysctl_sched_migration_cost,
322                 .maxlen         = sizeof(unsigned int),
323                 .mode           = 0644,
324                 .proc_handler   = &proc_dointvec,
325         },
326         {
327                 .ctl_name       = CTL_UNNUMBERED,
328                 .procname       = "sched_nr_migrate",
329                 .data           = &sysctl_sched_nr_migrate,
330                 .maxlen         = sizeof(unsigned int),
331                 .mode           = 0644,
332                 .proc_handler   = &proc_dointvec,
333         },
334         {
335                 .ctl_name       = CTL_UNNUMBERED,
336                 .procname       = "timer_migration",
337                 .data           = &sysctl_timer_migration,
338                 .maxlen         = sizeof(unsigned int),
339                 .mode           = 0644,
340                 .proc_handler   = &proc_dointvec_minmax,
341                 .strategy       = &sysctl_intvec,
342                 .extra1         = &zero,
343                 .extra2         = &one,
344         },
345 #endif
346         {
347                 .ctl_name       = CTL_UNNUMBERED,
348                 .procname       = "sched_rt_period_us",
349                 .data           = &sysctl_sched_rt_period,
350                 .maxlen         = sizeof(unsigned int),
351                 .mode           = 0644,
352                 .proc_handler   = &sched_rt_handler,
353         },
354         {
355                 .ctl_name       = CTL_UNNUMBERED,
356                 .procname       = "sched_rt_runtime_us",
357                 .data           = &sysctl_sched_rt_runtime,
358                 .maxlen         = sizeof(int),
359                 .mode           = 0644,
360                 .proc_handler   = &sched_rt_handler,
361         },
362         {
363                 .ctl_name       = CTL_UNNUMBERED,
364                 .procname       = "sched_compat_yield",
365                 .data           = &sysctl_sched_compat_yield,
366                 .maxlen         = sizeof(unsigned int),
367                 .mode           = 0644,
368                 .proc_handler   = &proc_dointvec,
369         },
370 #ifdef CONFIG_PROVE_LOCKING
371         {
372                 .ctl_name       = CTL_UNNUMBERED,
373                 .procname       = "prove_locking",
374                 .data           = &prove_locking,
375                 .maxlen         = sizeof(int),
376                 .mode           = 0644,
377                 .proc_handler   = &proc_dointvec,
378         },
379 #endif
380 #ifdef CONFIG_LOCK_STAT
381         {
382                 .ctl_name       = CTL_UNNUMBERED,
383                 .procname       = "lock_stat",
384                 .data           = &lock_stat,
385                 .maxlen         = sizeof(int),
386                 .mode           = 0644,
387                 .proc_handler   = &proc_dointvec,
388         },
389 #endif
390         {
391                 .ctl_name       = KERN_PANIC,
392                 .procname       = "panic",
393                 .data           = &panic_timeout,
394                 .maxlen         = sizeof(int),
395                 .mode           = 0644,
396                 .proc_handler   = &proc_dointvec,
397         },
398         {
399                 .ctl_name       = KERN_CORE_USES_PID,
400                 .procname       = "core_uses_pid",
401                 .data           = &core_uses_pid,
402                 .maxlen         = sizeof(int),
403                 .mode           = 0644,
404                 .proc_handler   = &proc_dointvec,
405         },
406         {
407                 .ctl_name       = KERN_CORE_PATTERN,
408                 .procname       = "core_pattern",
409                 .data           = core_pattern,
410                 .maxlen         = CORENAME_MAX_SIZE,
411                 .mode           = 0644,
412                 .proc_handler   = &proc_dostring,
413                 .strategy       = &sysctl_string,
414         },
415 #ifdef CONFIG_PROC_SYSCTL
416         {
417                 .procname       = "tainted",
418                 .maxlen         = sizeof(long),
419                 .mode           = 0644,
420                 .proc_handler   = &proc_taint,
421         },
422 #endif
423 #ifdef CONFIG_LATENCYTOP
424         {
425                 .procname       = "latencytop",
426                 .data           = &latencytop_enabled,
427                 .maxlen         = sizeof(int),
428                 .mode           = 0644,
429                 .proc_handler   = &proc_dointvec,
430         },
431 #endif
432 #ifdef CONFIG_BLK_DEV_INITRD
433         {
434                 .ctl_name       = KERN_REALROOTDEV,
435                 .procname       = "real-root-dev",
436                 .data           = &real_root_dev,
437                 .maxlen         = sizeof(int),
438                 .mode           = 0644,
439                 .proc_handler   = &proc_dointvec,
440         },
441 #endif
442         {
443                 .ctl_name       = CTL_UNNUMBERED,
444                 .procname       = "print-fatal-signals",
445                 .data           = &print_fatal_signals,
446                 .maxlen         = sizeof(int),
447                 .mode           = 0644,
448                 .proc_handler   = &proc_dointvec,
449         },
450 #ifdef CONFIG_SPARC
451         {
452                 .ctl_name       = KERN_SPARC_REBOOT,
453                 .procname       = "reboot-cmd",
454                 .data           = reboot_command,
455                 .maxlen         = 256,
456                 .mode           = 0644,
457                 .proc_handler   = &proc_dostring,
458                 .strategy       = &sysctl_string,
459         },
460         {
461                 .ctl_name       = KERN_SPARC_STOP_A,
462                 .procname       = "stop-a",
463                 .data           = &stop_a_enabled,
464                 .maxlen         = sizeof (int),
465                 .mode           = 0644,
466                 .proc_handler   = &proc_dointvec,
467         },
468         {
469                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
470                 .procname       = "scons-poweroff",
471                 .data           = &scons_pwroff,
472                 .maxlen         = sizeof (int),
473                 .mode           = 0644,
474                 .proc_handler   = &proc_dointvec,
475         },
476 #endif
477 #ifdef CONFIG_SPARC64
478         {
479                 .ctl_name       = CTL_UNNUMBERED,
480                 .procname       = "tsb-ratio",
481                 .data           = &sysctl_tsb_ratio,
482                 .maxlen         = sizeof (int),
483                 .mode           = 0644,
484                 .proc_handler   = &proc_dointvec,
485         },
486 #endif
487 #ifdef __hppa__
488         {
489                 .ctl_name       = KERN_HPPA_PWRSW,
490                 .procname       = "soft-power",
491                 .data           = &pwrsw_enabled,
492                 .maxlen         = sizeof (int),
493                 .mode           = 0644,
494                 .proc_handler   = &proc_dointvec,
495         },
496         {
497                 .ctl_name       = KERN_HPPA_UNALIGNED,
498                 .procname       = "unaligned-trap",
499                 .data           = &unaligned_enabled,
500                 .maxlen         = sizeof (int),
501                 .mode           = 0644,
502                 .proc_handler   = &proc_dointvec,
503         },
504 #endif
505         {
506                 .ctl_name       = KERN_CTLALTDEL,
507                 .procname       = "ctrl-alt-del",
508                 .data           = &C_A_D,
509                 .maxlen         = sizeof(int),
510                 .mode           = 0644,
511                 .proc_handler   = &proc_dointvec,
512         },
513 #ifdef CONFIG_FUNCTION_TRACER
514         {
515                 .ctl_name       = CTL_UNNUMBERED,
516                 .procname       = "ftrace_enabled",
517                 .data           = &ftrace_enabled,
518                 .maxlen         = sizeof(int),
519                 .mode           = 0644,
520                 .proc_handler   = &ftrace_enable_sysctl,
521         },
522 #endif
523 #ifdef CONFIG_STACK_TRACER
524         {
525                 .ctl_name       = CTL_UNNUMBERED,
526                 .procname       = "stack_tracer_enabled",
527                 .data           = &stack_tracer_enabled,
528                 .maxlen         = sizeof(int),
529                 .mode           = 0644,
530                 .proc_handler   = &stack_trace_sysctl,
531         },
532 #endif
533 #ifdef CONFIG_TRACING
534         {
535                 .ctl_name       = CTL_UNNUMBERED,
536                 .procname       = "ftrace_dump_on_oops",
537                 .data           = &ftrace_dump_on_oops,
538                 .maxlen         = sizeof(int),
539                 .mode           = 0644,
540                 .proc_handler   = &proc_dointvec,
541         },
542 #endif
543 #ifdef CONFIG_MODULES
544         {
545                 .ctl_name       = KERN_MODPROBE,
546                 .procname       = "modprobe",
547                 .data           = &modprobe_path,
548                 .maxlen         = KMOD_PATH_LEN,
549                 .mode           = 0644,
550                 .proc_handler   = &proc_dostring,
551                 .strategy       = &sysctl_string,
552         },
553         {
554                 .ctl_name       = CTL_UNNUMBERED,
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,
563         },
564 #endif
565 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
566         {
567                 .ctl_name       = KERN_HOTPLUG,
568                 .procname       = "hotplug",
569                 .data           = &uevent_helper,
570                 .maxlen         = UEVENT_HELPER_PATH_LEN,
571                 .mode           = 0644,
572                 .proc_handler   = &proc_dostring,
573                 .strategy       = &sysctl_string,
574         },
575 #endif
576 #ifdef CONFIG_CHR_DEV_SG
577         {
578                 .ctl_name       = KERN_SG_BIG_BUFF,
579                 .procname       = "sg-big-buff",
580                 .data           = &sg_big_buff,
581                 .maxlen         = sizeof (int),
582                 .mode           = 0444,
583                 .proc_handler   = &proc_dointvec,
584         },
585 #endif
586 #ifdef CONFIG_BSD_PROCESS_ACCT
587         {
588                 .ctl_name       = KERN_ACCT,
589                 .procname       = "acct",
590                 .data           = &acct_parm,
591                 .maxlen         = 3*sizeof(int),
592                 .mode           = 0644,
593                 .proc_handler   = &proc_dointvec,
594         },
595 #endif
596 #ifdef CONFIG_MAGIC_SYSRQ
597         {
598                 .ctl_name       = KERN_SYSRQ,
599                 .procname       = "sysrq",
600                 .data           = &__sysrq_enabled,
601                 .maxlen         = sizeof (int),
602                 .mode           = 0644,
603                 .proc_handler   = &proc_dointvec,
604         },
605 #endif
606 #ifdef CONFIG_PROC_SYSCTL
607         {
608                 .procname       = "cad_pid",
609                 .data           = NULL,
610                 .maxlen         = sizeof (int),
611                 .mode           = 0600,
612                 .proc_handler   = &proc_do_cad_pid,
613         },
614 #endif
615         {
616                 .ctl_name       = KERN_MAX_THREADS,
617                 .procname       = "threads-max",
618                 .data           = &max_threads,
619                 .maxlen         = sizeof(int),
620                 .mode           = 0644,
621                 .proc_handler   = &proc_dointvec,
622         },
623         {
624                 .ctl_name       = KERN_RANDOM,
625                 .procname       = "random",
626                 .mode           = 0555,
627                 .child          = random_table,
628         },
629         {
630                 .ctl_name       = KERN_OVERFLOWUID,
631                 .procname       = "overflowuid",
632                 .data           = &overflowuid,
633                 .maxlen         = sizeof(int),
634                 .mode           = 0644,
635                 .proc_handler   = &proc_dointvec_minmax,
636                 .strategy       = &sysctl_intvec,
637                 .extra1         = &minolduid,
638                 .extra2         = &maxolduid,
639         },
640         {
641                 .ctl_name       = KERN_OVERFLOWGID,
642                 .procname       = "overflowgid",
643                 .data           = &overflowgid,
644                 .maxlen         = sizeof(int),
645                 .mode           = 0644,
646                 .proc_handler   = &proc_dointvec_minmax,
647                 .strategy       = &sysctl_intvec,
648                 .extra1         = &minolduid,
649                 .extra2         = &maxolduid,
650         },
651 #ifdef CONFIG_S390
652 #ifdef CONFIG_MATHEMU
653         {
654                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
655                 .procname       = "ieee_emulation_warnings",
656                 .data           = &sysctl_ieee_emulation_warnings,
657                 .maxlen         = sizeof(int),
658                 .mode           = 0644,
659                 .proc_handler   = &proc_dointvec,
660         },
661 #endif
662         {
663                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
664                 .procname       = "userprocess_debug",
665                 .data           = &sysctl_userprocess_debug,
666                 .maxlen         = sizeof(int),
667                 .mode           = 0644,
668                 .proc_handler   = &proc_dointvec,
669         },
670 #endif
671         {
672                 .ctl_name       = KERN_PIDMAX,
673                 .procname       = "pid_max",
674                 .data           = &pid_max,
675                 .maxlen         = sizeof (int),
676                 .mode           = 0644,
677                 .proc_handler   = &proc_dointvec_minmax,
678                 .strategy       = sysctl_intvec,
679                 .extra1         = &pid_max_min,
680                 .extra2         = &pid_max_max,
681         },
682         {
683                 .ctl_name       = KERN_PANIC_ON_OOPS,
684                 .procname       = "panic_on_oops",
685                 .data           = &panic_on_oops,
686                 .maxlen         = sizeof(int),
687                 .mode           = 0644,
688                 .proc_handler   = &proc_dointvec,
689         },
690 #if defined CONFIG_PRINTK
691         {
692                 .ctl_name       = KERN_PRINTK,
693                 .procname       = "printk",
694                 .data           = &console_loglevel,
695                 .maxlen         = 4*sizeof(int),
696                 .mode           = 0644,
697                 .proc_handler   = &proc_dointvec,
698         },
699         {
700                 .ctl_name       = KERN_PRINTK_RATELIMIT,
701                 .procname       = "printk_ratelimit",
702                 .data           = &printk_ratelimit_state.interval,
703                 .maxlen         = sizeof(int),
704                 .mode           = 0644,
705                 .proc_handler   = &proc_dointvec_jiffies,
706                 .strategy       = &sysctl_jiffies,
707         },
708         {
709                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
710                 .procname       = "printk_ratelimit_burst",
711                 .data           = &printk_ratelimit_state.burst,
712                 .maxlen         = sizeof(int),
713                 .mode           = 0644,
714                 .proc_handler   = &proc_dointvec,
715         },
716 #endif
717         {
718                 .ctl_name       = KERN_NGROUPS_MAX,
719                 .procname       = "ngroups_max",
720                 .data           = &ngroups_max,
721                 .maxlen         = sizeof (int),
722                 .mode           = 0444,
723                 .proc_handler   = &proc_dointvec,
724         },
725 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
726         {
727                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
728                 .procname       = "unknown_nmi_panic",
729                 .data           = &unknown_nmi_panic,
730                 .maxlen         = sizeof (int),
731                 .mode           = 0644,
732                 .proc_handler   = &proc_dointvec,
733         },
734         {
735                 .procname       = "nmi_watchdog",
736                 .data           = &nmi_watchdog_enabled,
737                 .maxlen         = sizeof (int),
738                 .mode           = 0644,
739                 .proc_handler   = &proc_nmi_enabled,
740         },
741 #endif
742 #if defined(CONFIG_X86)
743         {
744                 .ctl_name       = KERN_PANIC_ON_NMI,
745                 .procname       = "panic_on_unrecovered_nmi",
746                 .data           = &panic_on_unrecovered_nmi,
747                 .maxlen         = sizeof(int),
748                 .mode           = 0644,
749                 .proc_handler   = &proc_dointvec,
750         },
751         {
752                 .ctl_name       = CTL_UNNUMBERED,
753                 .procname       = "panic_on_io_nmi",
754                 .data           = &panic_on_io_nmi,
755                 .maxlen         = sizeof(int),
756                 .mode           = 0644,
757                 .proc_handler   = &proc_dointvec,
758         },
759         {
760                 .ctl_name       = KERN_BOOTLOADER_TYPE,
761                 .procname       = "bootloader_type",
762                 .data           = &bootloader_type,
763                 .maxlen         = sizeof (int),
764                 .mode           = 0444,
765                 .proc_handler   = &proc_dointvec,
766         },
767         {
768                 .ctl_name       = CTL_UNNUMBERED,
769                 .procname       = "bootloader_version",
770                 .data           = &bootloader_version,
771                 .maxlen         = sizeof (int),
772                 .mode           = 0444,
773                 .proc_handler   = &proc_dointvec,
774         },
775         {
776                 .ctl_name       = CTL_UNNUMBERED,
777                 .procname       = "kstack_depth_to_print",
778                 .data           = &kstack_depth_to_print,
779                 .maxlen         = sizeof(int),
780                 .mode           = 0644,
781                 .proc_handler   = &proc_dointvec,
782         },
783         {
784                 .ctl_name       = CTL_UNNUMBERED,
785                 .procname       = "io_delay_type",
786                 .data           = &io_delay_type,
787                 .maxlen         = sizeof(int),
788                 .mode           = 0644,
789                 .proc_handler   = &proc_dointvec,
790         },
791 #endif
792 #if defined(CONFIG_MMU)
793         {
794                 .ctl_name       = KERN_RANDOMIZE,
795                 .procname       = "randomize_va_space",
796                 .data           = &randomize_va_space,
797                 .maxlen         = sizeof(int),
798                 .mode           = 0644,
799                 .proc_handler   = &proc_dointvec,
800         },
801 #endif
802 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
803         {
804                 .ctl_name       = KERN_SPIN_RETRY,
805                 .procname       = "spin_retry",
806                 .data           = &spin_retry,
807                 .maxlen         = sizeof (int),
808                 .mode           = 0644,
809                 .proc_handler   = &proc_dointvec,
810         },
811 #endif
812 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
813         {
814                 .procname       = "acpi_video_flags",
815                 .data           = &acpi_realmode_flags,
816                 .maxlen         = sizeof (unsigned long),
817                 .mode           = 0644,
818                 .proc_handler   = &proc_doulongvec_minmax,
819         },
820 #endif
821 #ifdef CONFIG_IA64
822         {
823                 .ctl_name       = KERN_IA64_UNALIGNED,
824                 .procname       = "ignore-unaligned-usertrap",
825                 .data           = &no_unaligned_warning,
826                 .maxlen         = sizeof (int),
827                 .mode           = 0644,
828                 .proc_handler   = &proc_dointvec,
829         },
830         {
831                 .ctl_name       = CTL_UNNUMBERED,
832                 .procname       = "unaligned-dump-stack",
833                 .data           = &unaligned_dump_stack,
834                 .maxlen         = sizeof (int),
835                 .mode           = 0644,
836                 .proc_handler   = &proc_dointvec,
837         },
838 #endif
839 #ifdef CONFIG_DETECT_SOFTLOCKUP
840         {
841                 .ctl_name       = CTL_UNNUMBERED,
842                 .procname       = "softlockup_panic",
843                 .data           = &softlockup_panic,
844                 .maxlen         = sizeof(int),
845                 .mode           = 0644,
846                 .proc_handler   = &proc_dointvec_minmax,
847                 .strategy       = &sysctl_intvec,
848                 .extra1         = &zero,
849                 .extra2         = &one,
850         },
851         {
852                 .ctl_name       = CTL_UNNUMBERED,
853                 .procname       = "softlockup_thresh",
854                 .data           = &softlockup_thresh,
855                 .maxlen         = sizeof(int),
856                 .mode           = 0644,
857                 .proc_handler   = &proc_dosoftlockup_thresh,
858                 .strategy       = &sysctl_intvec,
859                 .extra1         = &neg_one,
860                 .extra2         = &sixty,
861         },
862 #endif
863 #ifdef CONFIG_DETECT_HUNG_TASK
864         {
865                 .ctl_name       = CTL_UNNUMBERED,
866                 .procname       = "hung_task_panic",
867                 .data           = &sysctl_hung_task_panic,
868                 .maxlen         = sizeof(int),
869                 .mode           = 0644,
870                 .proc_handler   = &proc_dointvec_minmax,
871                 .strategy       = &sysctl_intvec,
872                 .extra1         = &zero,
873                 .extra2         = &one,
874         },
875         {
876                 .ctl_name       = CTL_UNNUMBERED,
877                 .procname       = "hung_task_check_count",
878                 .data           = &sysctl_hung_task_check_count,
879                 .maxlen         = sizeof(unsigned long),
880                 .mode           = 0644,
881                 .proc_handler   = &proc_doulongvec_minmax,
882                 .strategy       = &sysctl_intvec,
883         },
884         {
885                 .ctl_name       = CTL_UNNUMBERED,
886                 .procname       = "hung_task_timeout_secs",
887                 .data           = &sysctl_hung_task_timeout_secs,
888                 .maxlen         = sizeof(unsigned long),
889                 .mode           = 0644,
890                 .proc_handler   = &proc_dohung_task_timeout_secs,
891                 .strategy       = &sysctl_intvec,
892         },
893         {
894                 .ctl_name       = CTL_UNNUMBERED,
895                 .procname       = "hung_task_warnings",
896                 .data           = &sysctl_hung_task_warnings,
897                 .maxlen         = sizeof(unsigned long),
898                 .mode           = 0644,
899                 .proc_handler   = &proc_doulongvec_minmax,
900                 .strategy       = &sysctl_intvec,
901         },
902 #endif
903 #ifdef CONFIG_COMPAT
904         {
905                 .ctl_name       = KERN_COMPAT_LOG,
906                 .procname       = "compat-log",
907                 .data           = &compat_log,
908                 .maxlen         = sizeof (int),
909                 .mode           = 0644,
910                 .proc_handler   = &proc_dointvec,
911         },
912 #endif
913 #ifdef CONFIG_RT_MUTEXES
914         {
915                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
916                 .procname       = "max_lock_depth",
917                 .data           = &max_lock_depth,
918                 .maxlen         = sizeof(int),
919                 .mode           = 0644,
920                 .proc_handler   = &proc_dointvec,
921         },
922 #endif
923         {
924                 .ctl_name       = CTL_UNNUMBERED,
925                 .procname       = "poweroff_cmd",
926                 .data           = &poweroff_cmd,
927                 .maxlen         = POWEROFF_CMD_PATH_LEN,
928                 .mode           = 0644,
929                 .proc_handler   = &proc_dostring,
930                 .strategy       = &sysctl_string,
931         },
932 #ifdef CONFIG_KEYS
933         {
934                 .ctl_name       = CTL_UNNUMBERED,
935                 .procname       = "keys",
936                 .mode           = 0555,
937                 .child          = key_sysctls,
938         },
939 #endif
940 #ifdef CONFIG_RCU_TORTURE_TEST
941         {
942                 .ctl_name       = CTL_UNNUMBERED,
943                 .procname       = "rcutorture_runnable",
944                 .data           = &rcutorture_runnable,
945                 .maxlen         = sizeof(int),
946                 .mode           = 0644,
947                 .proc_handler   = &proc_dointvec,
948         },
949 #endif
950 #ifdef CONFIG_SLOW_WORK
951         {
952                 .ctl_name       = CTL_UNNUMBERED,
953                 .procname       = "slow-work",
954                 .mode           = 0555,
955                 .child          = slow_work_sysctls,
956         },
957 #endif
958 #ifdef CONFIG_PERF_COUNTERS
959         {
960                 .ctl_name       = CTL_UNNUMBERED,
961                 .procname       = "perf_counter_paranoid",
962                 .data           = &sysctl_perf_counter_paranoid,
963                 .maxlen         = sizeof(sysctl_perf_counter_paranoid),
964                 .mode           = 0644,
965                 .proc_handler   = &proc_dointvec,
966         },
967         {
968                 .ctl_name       = CTL_UNNUMBERED,
969                 .procname       = "perf_counter_mlock_kb",
970                 .data           = &sysctl_perf_counter_mlock,
971                 .maxlen         = sizeof(sysctl_perf_counter_mlock),
972                 .mode           = 0644,
973                 .proc_handler   = &proc_dointvec,
974         },
975         {
976                 .ctl_name       = CTL_UNNUMBERED,
977                 .procname       = "perf_counter_max_sample_rate",
978                 .data           = &sysctl_perf_counter_sample_rate,
979                 .maxlen         = sizeof(sysctl_perf_counter_sample_rate),
980                 .mode           = 0644,
981                 .proc_handler   = &proc_dointvec,
982         },
983 #endif
984 #ifdef CONFIG_KMEMCHECK
985         {
986                 .ctl_name       = CTL_UNNUMBERED,
987                 .procname       = "kmemcheck",
988                 .data           = &kmemcheck_enabled,
989                 .maxlen         = sizeof(int),
990                 .mode           = 0644,
991                 .proc_handler   = &proc_dointvec,
992         },
993 #endif
994         {
995                 .ctl_name       = CTL_UNNUMBERED,
996                 .procname       = "blk_iopoll",
997                 .data           = &blk_iopoll_enabled,
998                 .maxlen         = sizeof(int),
999                 .mode           = 0644,
1000                 .proc_handler   = &proc_dointvec,
1001         },
1002 /*
1003  * NOTE: do not add new entries to this table unless you have read
1004  * Documentation/sysctl/ctl_unnumbered.txt
1005  */
1006         { .ctl_name = 0 }
1007 };
1008
1009 static struct ctl_table vm_table[] = {
1010         {
1011                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
1012                 .procname       = "overcommit_memory",
1013                 .data           = &sysctl_overcommit_memory,
1014                 .maxlen         = sizeof(sysctl_overcommit_memory),
1015                 .mode           = 0644,
1016                 .proc_handler   = &proc_dointvec,
1017         },
1018         {
1019                 .ctl_name       = VM_PANIC_ON_OOM,
1020                 .procname       = "panic_on_oom",
1021                 .data           = &sysctl_panic_on_oom,
1022                 .maxlen         = sizeof(sysctl_panic_on_oom),
1023                 .mode           = 0644,
1024                 .proc_handler   = &proc_dointvec,
1025         },
1026         {
1027                 .ctl_name       = CTL_UNNUMBERED,
1028                 .procname       = "oom_kill_allocating_task",
1029                 .data           = &sysctl_oom_kill_allocating_task,
1030                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1031                 .mode           = 0644,
1032                 .proc_handler   = &proc_dointvec,
1033         },
1034         {
1035                 .ctl_name       = CTL_UNNUMBERED,
1036                 .procname       = "oom_dump_tasks",
1037                 .data           = &sysctl_oom_dump_tasks,
1038                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1039                 .mode           = 0644,
1040                 .proc_handler   = &proc_dointvec,
1041         },
1042         {
1043                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1044                 .procname       = "overcommit_ratio",
1045                 .data           = &sysctl_overcommit_ratio,
1046                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1047                 .mode           = 0644,
1048                 .proc_handler   = &proc_dointvec,
1049         },
1050         {
1051                 .ctl_name       = VM_PAGE_CLUSTER,
1052                 .procname       = "page-cluster", 
1053                 .data           = &page_cluster,
1054                 .maxlen         = sizeof(int),
1055                 .mode           = 0644,
1056                 .proc_handler   = &proc_dointvec,
1057         },
1058         {
1059                 .ctl_name       = VM_DIRTY_BACKGROUND,
1060                 .procname       = "dirty_background_ratio",
1061                 .data           = &dirty_background_ratio,
1062                 .maxlen         = sizeof(dirty_background_ratio),
1063                 .mode           = 0644,
1064                 .proc_handler   = &dirty_background_ratio_handler,
1065                 .strategy       = &sysctl_intvec,
1066                 .extra1         = &zero,
1067                 .extra2         = &one_hundred,
1068         },
1069         {
1070                 .ctl_name       = CTL_UNNUMBERED,
1071                 .procname       = "dirty_background_bytes",
1072                 .data           = &dirty_background_bytes,
1073                 .maxlen         = sizeof(dirty_background_bytes),
1074                 .mode           = 0644,
1075                 .proc_handler   = &dirty_background_bytes_handler,
1076                 .strategy       = &sysctl_intvec,
1077                 .extra1         = &one_ul,
1078         },
1079         {
1080                 .ctl_name       = VM_DIRTY_RATIO,
1081                 .procname       = "dirty_ratio",
1082                 .data           = &vm_dirty_ratio,
1083                 .maxlen         = sizeof(vm_dirty_ratio),
1084                 .mode           = 0644,
1085                 .proc_handler   = &dirty_ratio_handler,
1086                 .strategy       = &sysctl_intvec,
1087                 .extra1         = &zero,
1088                 .extra2         = &one_hundred,
1089         },
1090         {
1091                 .ctl_name       = CTL_UNNUMBERED,
1092                 .procname       = "dirty_bytes",
1093                 .data           = &vm_dirty_bytes,
1094                 .maxlen         = sizeof(vm_dirty_bytes),
1095                 .mode           = 0644,
1096                 .proc_handler   = &dirty_bytes_handler,
1097                 .strategy       = &sysctl_intvec,
1098                 .extra1         = &dirty_bytes_min,
1099         },
1100         {
1101                 .procname       = "dirty_writeback_centisecs",
1102                 .data           = &dirty_writeback_interval,
1103                 .maxlen         = sizeof(dirty_writeback_interval),
1104                 .mode           = 0644,
1105                 .proc_handler   = &dirty_writeback_centisecs_handler,
1106         },
1107         {
1108                 .procname       = "dirty_expire_centisecs",
1109                 .data           = &dirty_expire_interval,
1110                 .maxlen         = sizeof(dirty_expire_interval),
1111                 .mode           = 0644,
1112                 .proc_handler   = &proc_dointvec,
1113         },
1114         {
1115                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1116                 .procname       = "nr_pdflush_threads",
1117                 .data           = &nr_pdflush_threads,
1118                 .maxlen         = sizeof nr_pdflush_threads,
1119                 .mode           = 0444 /* read-only*/,
1120                 .proc_handler   = &proc_dointvec,
1121         },
1122         {
1123                 .ctl_name       = VM_SWAPPINESS,
1124                 .procname       = "swappiness",
1125                 .data           = &vm_swappiness,
1126                 .maxlen         = sizeof(vm_swappiness),
1127                 .mode           = 0644,
1128                 .proc_handler   = &proc_dointvec_minmax,
1129                 .strategy       = &sysctl_intvec,
1130                 .extra1         = &zero,
1131                 .extra2         = &one_hundred,
1132         },
1133 #ifdef CONFIG_HUGETLB_PAGE
1134          {
1135                 .procname       = "nr_hugepages",
1136                 .data           = NULL,
1137                 .maxlen         = sizeof(unsigned long),
1138                 .mode           = 0644,
1139                 .proc_handler   = &hugetlb_sysctl_handler,
1140                 .extra1         = (void *)&hugetlb_zero,
1141                 .extra2         = (void *)&hugetlb_infinity,
1142          },
1143          {
1144                 .ctl_name       = VM_HUGETLB_GROUP,
1145                 .procname       = "hugetlb_shm_group",
1146                 .data           = &sysctl_hugetlb_shm_group,
1147                 .maxlen         = sizeof(gid_t),
1148                 .mode           = 0644,
1149                 .proc_handler   = &proc_dointvec,
1150          },
1151          {
1152                 .ctl_name       = CTL_UNNUMBERED,
1153                 .procname       = "hugepages_treat_as_movable",
1154                 .data           = &hugepages_treat_as_movable,
1155                 .maxlen         = sizeof(int),
1156                 .mode           = 0644,
1157                 .proc_handler   = &hugetlb_treat_movable_handler,
1158         },
1159         {
1160                 .ctl_name       = CTL_UNNUMBERED,
1161                 .procname       = "nr_overcommit_hugepages",
1162                 .data           = NULL,
1163                 .maxlen         = sizeof(unsigned long),
1164                 .mode           = 0644,
1165                 .proc_handler   = &hugetlb_overcommit_handler,
1166                 .extra1         = (void *)&hugetlb_zero,
1167                 .extra2         = (void *)&hugetlb_infinity,
1168         },
1169 #endif
1170         {
1171                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1172                 .procname       = "lowmem_reserve_ratio",
1173                 .data           = &sysctl_lowmem_reserve_ratio,
1174                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1175                 .mode           = 0644,
1176                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1177                 .strategy       = &sysctl_intvec,
1178         },
1179         {
1180                 .ctl_name       = VM_DROP_PAGECACHE,
1181                 .procname       = "drop_caches",
1182                 .data           = &sysctl_drop_caches,
1183                 .maxlen         = sizeof(int),
1184                 .mode           = 0644,
1185                 .proc_handler   = drop_caches_sysctl_handler,
1186                 .strategy       = &sysctl_intvec,
1187         },
1188         {
1189                 .ctl_name       = VM_MIN_FREE_KBYTES,
1190                 .procname       = "min_free_kbytes",
1191                 .data           = &min_free_kbytes,
1192                 .maxlen         = sizeof(min_free_kbytes),
1193                 .mode           = 0644,
1194                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1195                 .strategy       = &sysctl_intvec,
1196                 .extra1         = &zero,
1197         },
1198         {
1199                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1200                 .procname       = "percpu_pagelist_fraction",
1201                 .data           = &percpu_pagelist_fraction,
1202                 .maxlen         = sizeof(percpu_pagelist_fraction),
1203                 .mode           = 0644,
1204                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1205                 .strategy       = &sysctl_intvec,
1206                 .extra1         = &min_percpu_pagelist_fract,
1207         },
1208 #ifdef CONFIG_MMU
1209         {
1210                 .ctl_name       = VM_MAX_MAP_COUNT,
1211                 .procname       = "max_map_count",
1212                 .data           = &sysctl_max_map_count,
1213                 .maxlen         = sizeof(sysctl_max_map_count),
1214                 .mode           = 0644,
1215                 .proc_handler   = &proc_dointvec
1216         },
1217 #else
1218         {
1219                 .ctl_name       = CTL_UNNUMBERED,
1220                 .procname       = "nr_trim_pages",
1221                 .data           = &sysctl_nr_trim_pages,
1222                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1223                 .mode           = 0644,
1224                 .proc_handler   = &proc_dointvec_minmax,
1225                 .strategy       = &sysctl_intvec,
1226                 .extra1         = &zero,
1227         },
1228 #endif
1229         {
1230                 .ctl_name       = VM_LAPTOP_MODE,
1231                 .procname       = "laptop_mode",
1232                 .data           = &laptop_mode,
1233                 .maxlen         = sizeof(laptop_mode),
1234                 .mode           = 0644,
1235                 .proc_handler   = &proc_dointvec_jiffies,
1236                 .strategy       = &sysctl_jiffies,
1237         },
1238         {
1239                 .ctl_name       = VM_BLOCK_DUMP,
1240                 .procname       = "block_dump",
1241                 .data           = &block_dump,
1242                 .maxlen         = sizeof(block_dump),
1243                 .mode           = 0644,
1244                 .proc_handler   = &proc_dointvec,
1245                 .strategy       = &sysctl_intvec,
1246                 .extra1         = &zero,
1247         },
1248         {
1249                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1250                 .procname       = "vfs_cache_pressure",
1251                 .data           = &sysctl_vfs_cache_pressure,
1252                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1253                 .mode           = 0644,
1254                 .proc_handler   = &proc_dointvec,
1255                 .strategy       = &sysctl_intvec,
1256                 .extra1         = &zero,
1257         },
1258 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1259         {
1260                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1261                 .procname       = "legacy_va_layout",
1262                 .data           = &sysctl_legacy_va_layout,
1263                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1264                 .mode           = 0644,
1265                 .proc_handler   = &proc_dointvec,
1266                 .strategy       = &sysctl_intvec,
1267                 .extra1         = &zero,
1268         },
1269 #endif
1270 #ifdef CONFIG_NUMA
1271         {
1272                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1273                 .procname       = "zone_reclaim_mode",
1274                 .data           = &zone_reclaim_mode,
1275                 .maxlen         = sizeof(zone_reclaim_mode),
1276                 .mode           = 0644,
1277                 .proc_handler   = &proc_dointvec,
1278                 .strategy       = &sysctl_intvec,
1279                 .extra1         = &zero,
1280         },
1281         {
1282                 .ctl_name       = VM_MIN_UNMAPPED,
1283                 .procname       = "min_unmapped_ratio",
1284                 .data           = &sysctl_min_unmapped_ratio,
1285                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1286                 .mode           = 0644,
1287                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1288                 .strategy       = &sysctl_intvec,
1289                 .extra1         = &zero,
1290                 .extra2         = &one_hundred,
1291         },
1292         {
1293                 .ctl_name       = VM_MIN_SLAB,
1294                 .procname       = "min_slab_ratio",
1295                 .data           = &sysctl_min_slab_ratio,
1296                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1297                 .mode           = 0644,
1298                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1299                 .strategy       = &sysctl_intvec,
1300                 .extra1         = &zero,
1301                 .extra2         = &one_hundred,
1302         },
1303 #endif
1304 #ifdef CONFIG_SMP
1305         {
1306                 .ctl_name       = CTL_UNNUMBERED,
1307                 .procname       = "stat_interval",
1308                 .data           = &sysctl_stat_interval,
1309                 .maxlen         = sizeof(sysctl_stat_interval),
1310                 .mode           = 0644,
1311                 .proc_handler   = &proc_dointvec_jiffies,
1312                 .strategy       = &sysctl_jiffies,
1313         },
1314 #endif
1315         {
1316                 .ctl_name       = CTL_UNNUMBERED,
1317                 .procname       = "mmap_min_addr",
1318                 .data           = &dac_mmap_min_addr,
1319                 .maxlen         = sizeof(unsigned long),
1320                 .mode           = 0644,
1321                 .proc_handler   = &mmap_min_addr_handler,
1322         },
1323 #ifdef CONFIG_NUMA
1324         {
1325                 .ctl_name       = CTL_UNNUMBERED,
1326                 .procname       = "numa_zonelist_order",
1327                 .data           = &numa_zonelist_order,
1328                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1329                 .mode           = 0644,
1330                 .proc_handler   = &numa_zonelist_order_handler,
1331                 .strategy       = &sysctl_string,
1332         },
1333 #endif
1334 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1335    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1336         {
1337                 .ctl_name       = VM_VDSO_ENABLED,
1338                 .procname       = "vdso_enabled",
1339                 .data           = &vdso_enabled,
1340                 .maxlen         = sizeof(vdso_enabled),
1341                 .mode           = 0644,
1342                 .proc_handler   = &proc_dointvec,
1343                 .strategy       = &sysctl_intvec,
1344                 .extra1         = &zero,
1345         },
1346 #endif
1347 #ifdef CONFIG_HIGHMEM
1348         {
1349                 .ctl_name       = CTL_UNNUMBERED,
1350                 .procname       = "highmem_is_dirtyable",
1351                 .data           = &vm_highmem_is_dirtyable,
1352                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1353                 .mode           = 0644,
1354                 .proc_handler   = &proc_dointvec_minmax,
1355                 .strategy       = &sysctl_intvec,
1356                 .extra1         = &zero,
1357                 .extra2         = &one,
1358         },
1359 #endif
1360         {
1361                 .ctl_name       = CTL_UNNUMBERED,
1362                 .procname       = "scan_unevictable_pages",
1363                 .data           = &scan_unevictable_pages,
1364                 .maxlen         = sizeof(scan_unevictable_pages),
1365                 .mode           = 0644,
1366                 .proc_handler   = &scan_unevictable_handler,
1367         },
1368 /*
1369  * NOTE: do not add new entries to this table unless you have read
1370  * Documentation/sysctl/ctl_unnumbered.txt
1371  */
1372         { .ctl_name = 0 }
1373 };
1374
1375 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1376 static struct ctl_table binfmt_misc_table[] = {
1377         { .ctl_name = 0 }
1378 };
1379 #endif
1380
1381 static struct ctl_table fs_table[] = {
1382         {
1383                 .ctl_name       = FS_NRINODE,
1384                 .procname       = "inode-nr",
1385                 .data           = &inodes_stat,
1386                 .maxlen         = 2*sizeof(int),
1387                 .mode           = 0444,
1388                 .proc_handler   = &proc_dointvec,
1389         },
1390         {
1391                 .ctl_name       = FS_STATINODE,
1392                 .procname       = "inode-state",
1393                 .data           = &inodes_stat,
1394                 .maxlen         = 7*sizeof(int),
1395                 .mode           = 0444,
1396                 .proc_handler   = &proc_dointvec,
1397         },
1398         {
1399                 .procname       = "file-nr",
1400                 .data           = &files_stat,
1401                 .maxlen         = 3*sizeof(int),
1402                 .mode           = 0444,
1403                 .proc_handler   = &proc_nr_files,
1404         },
1405         {
1406                 .ctl_name       = FS_MAXFILE,
1407                 .procname       = "file-max",
1408                 .data           = &files_stat.max_files,
1409                 .maxlen         = sizeof(int),
1410                 .mode           = 0644,
1411                 .proc_handler   = &proc_dointvec,
1412         },
1413         {
1414                 .ctl_name       = CTL_UNNUMBERED,
1415                 .procname       = "nr_open",
1416                 .data           = &sysctl_nr_open,
1417                 .maxlen         = sizeof(int),
1418                 .mode           = 0644,
1419                 .proc_handler   = &proc_dointvec_minmax,
1420                 .extra1         = &sysctl_nr_open_min,
1421                 .extra2         = &sysctl_nr_open_max,
1422         },
1423         {
1424                 .ctl_name       = FS_DENTRY,
1425                 .procname       = "dentry-state",
1426                 .data           = &dentry_stat,
1427                 .maxlen         = 6*sizeof(int),
1428                 .mode           = 0444,
1429                 .proc_handler   = &proc_dointvec,
1430         },
1431         {
1432                 .ctl_name       = FS_OVERFLOWUID,
1433                 .procname       = "overflowuid",
1434                 .data           = &fs_overflowuid,
1435                 .maxlen         = sizeof(int),
1436                 .mode           = 0644,
1437                 .proc_handler   = &proc_dointvec_minmax,
1438                 .strategy       = &sysctl_intvec,
1439                 .extra1         = &minolduid,
1440                 .extra2         = &maxolduid,
1441         },
1442         {
1443                 .ctl_name       = FS_OVERFLOWGID,
1444                 .procname       = "overflowgid",
1445                 .data           = &fs_overflowgid,
1446                 .maxlen         = sizeof(int),
1447                 .mode           = 0644,
1448                 .proc_handler   = &proc_dointvec_minmax,
1449                 .strategy       = &sysctl_intvec,
1450                 .extra1         = &minolduid,
1451                 .extra2         = &maxolduid,
1452         },
1453 #ifdef CONFIG_FILE_LOCKING
1454         {
1455                 .ctl_name       = FS_LEASES,
1456                 .procname       = "leases-enable",
1457                 .data           = &leases_enable,
1458                 .maxlen         = sizeof(int),
1459                 .mode           = 0644,
1460                 .proc_handler   = &proc_dointvec,
1461         },
1462 #endif
1463 #ifdef CONFIG_DNOTIFY
1464         {
1465                 .ctl_name       = FS_DIR_NOTIFY,
1466                 .procname       = "dir-notify-enable",
1467                 .data           = &dir_notify_enable,
1468                 .maxlen         = sizeof(int),
1469                 .mode           = 0644,
1470                 .proc_handler   = &proc_dointvec,
1471         },
1472 #endif
1473 #ifdef CONFIG_MMU
1474 #ifdef CONFIG_FILE_LOCKING
1475         {
1476                 .ctl_name       = FS_LEASE_TIME,
1477                 .procname       = "lease-break-time",
1478                 .data           = &lease_break_time,
1479                 .maxlen         = sizeof(int),
1480                 .mode           = 0644,
1481                 .proc_handler   = &proc_dointvec,
1482         },
1483 #endif
1484 #ifdef CONFIG_AIO
1485         {
1486                 .procname       = "aio-nr",
1487                 .data           = &aio_nr,
1488                 .maxlen         = sizeof(aio_nr),
1489                 .mode           = 0444,
1490                 .proc_handler   = &proc_doulongvec_minmax,
1491         },
1492         {
1493                 .procname       = "aio-max-nr",
1494                 .data           = &aio_max_nr,
1495                 .maxlen         = sizeof(aio_max_nr),
1496                 .mode           = 0644,
1497                 .proc_handler   = &proc_doulongvec_minmax,
1498         },
1499 #endif /* CONFIG_AIO */
1500 #ifdef CONFIG_INOTIFY_USER
1501         {
1502                 .ctl_name       = FS_INOTIFY,
1503                 .procname       = "inotify",
1504                 .mode           = 0555,
1505                 .child          = inotify_table,
1506         },
1507 #endif  
1508 #ifdef CONFIG_EPOLL
1509         {
1510                 .procname       = "epoll",
1511                 .mode           = 0555,
1512                 .child          = epoll_table,
1513         },
1514 #endif
1515 #endif
1516         {
1517                 .ctl_name       = KERN_SETUID_DUMPABLE,
1518                 .procname       = "suid_dumpable",
1519                 .data           = &suid_dumpable,
1520                 .maxlen         = sizeof(int),
1521                 .mode           = 0644,
1522                 .proc_handler   = &proc_dointvec_minmax,
1523                 .strategy       = &sysctl_intvec,
1524                 .extra1         = &zero,
1525                 .extra2         = &two,
1526         },
1527 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1528         {
1529                 .ctl_name       = CTL_UNNUMBERED,
1530                 .procname       = "binfmt_misc",
1531                 .mode           = 0555,
1532                 .child          = binfmt_misc_table,
1533         },
1534 #endif
1535 /*
1536  * NOTE: do not add new entries to this table unless you have read
1537  * Documentation/sysctl/ctl_unnumbered.txt
1538  */
1539         { .ctl_name = 0 }
1540 };
1541
1542 static struct ctl_table debug_table[] = {
1543 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1544         {
1545                 .ctl_name       = CTL_UNNUMBERED,
1546                 .procname       = "exception-trace",
1547                 .data           = &show_unhandled_signals,
1548                 .maxlen         = sizeof(int),
1549                 .mode           = 0644,
1550                 .proc_handler   = proc_dointvec
1551         },
1552 #endif
1553         { .ctl_name = 0 }
1554 };
1555
1556 static struct ctl_table dev_table[] = {
1557         { .ctl_name = 0 }
1558 };
1559
1560 static DEFINE_SPINLOCK(sysctl_lock);
1561
1562 /* called under sysctl_lock */
1563 static int use_table(struct ctl_table_header *p)
1564 {
1565         if (unlikely(p->unregistering))
1566                 return 0;
1567         p->used++;
1568         return 1;
1569 }
1570
1571 /* called under sysctl_lock */
1572 static void unuse_table(struct ctl_table_header *p)
1573 {
1574         if (!--p->used)
1575                 if (unlikely(p->unregistering))
1576                         complete(p->unregistering);
1577 }
1578
1579 /* called under sysctl_lock, will reacquire if has to wait */
1580 static void start_unregistering(struct ctl_table_header *p)
1581 {
1582         /*
1583          * if p->used is 0, nobody will ever touch that entry again;
1584          * we'll eliminate all paths to it before dropping sysctl_lock
1585          */
1586         if (unlikely(p->used)) {
1587                 struct completion wait;
1588                 init_completion(&wait);
1589                 p->unregistering = &wait;
1590                 spin_unlock(&sysctl_lock);
1591                 wait_for_completion(&wait);
1592                 spin_lock(&sysctl_lock);
1593         } else {
1594                 /* anything non-NULL; we'll never dereference it */
1595                 p->unregistering = ERR_PTR(-EINVAL);
1596         }
1597         /*
1598          * do not remove from the list until nobody holds it; walking the
1599          * list in do_sysctl() relies on that.
1600          */
1601         list_del_init(&p->ctl_entry);
1602 }
1603
1604 void sysctl_head_get(struct ctl_table_header *head)
1605 {
1606         spin_lock(&sysctl_lock);
1607         head->count++;
1608         spin_unlock(&sysctl_lock);
1609 }
1610
1611 void sysctl_head_put(struct ctl_table_header *head)
1612 {
1613         spin_lock(&sysctl_lock);
1614         if (!--head->count)
1615                 kfree(head);
1616         spin_unlock(&sysctl_lock);
1617 }
1618
1619 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1620 {
1621         if (!head)
1622                 BUG();
1623         spin_lock(&sysctl_lock);
1624         if (!use_table(head))
1625                 head = ERR_PTR(-ENOENT);
1626         spin_unlock(&sysctl_lock);
1627         return head;
1628 }
1629
1630 void sysctl_head_finish(struct ctl_table_header *head)
1631 {
1632         if (!head)
1633                 return;
1634         spin_lock(&sysctl_lock);
1635         unuse_table(head);
1636         spin_unlock(&sysctl_lock);
1637 }
1638
1639 static struct ctl_table_set *
1640 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1641 {
1642         struct ctl_table_set *set = &root->default_set;
1643         if (root->lookup)
1644                 set = root->lookup(root, namespaces);
1645         return set;
1646 }
1647
1648 static struct list_head *
1649 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1650 {
1651         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1652         return &set->list;
1653 }
1654
1655 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1656                                             struct ctl_table_header *prev)
1657 {
1658         struct ctl_table_root *root;
1659         struct list_head *header_list;
1660         struct ctl_table_header *head;
1661         struct list_head *tmp;
1662
1663         spin_lock(&sysctl_lock);
1664         if (prev) {
1665                 head = prev;
1666                 tmp = &prev->ctl_entry;
1667                 unuse_table(prev);
1668                 goto next;
1669         }
1670         tmp = &root_table_header.ctl_entry;
1671         for (;;) {
1672                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1673
1674                 if (!use_table(head))
1675                         goto next;
1676                 spin_unlock(&sysctl_lock);
1677                 return head;
1678         next:
1679                 root = head->root;
1680                 tmp = tmp->next;
1681                 header_list = lookup_header_list(root, namespaces);
1682                 if (tmp != header_list)
1683                         continue;
1684
1685                 do {
1686                         root = list_entry(root->root_list.next,
1687                                         struct ctl_table_root, root_list);
1688                         if (root == &sysctl_table_root)
1689                                 goto out;
1690                         header_list = lookup_header_list(root, namespaces);
1691                 } while (list_empty(header_list));
1692                 tmp = header_list->next;
1693         }
1694 out:
1695         spin_unlock(&sysctl_lock);
1696         return NULL;
1697 }
1698
1699 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1700 {
1701         return __sysctl_head_next(current->nsproxy, prev);
1702 }
1703
1704 void register_sysctl_root(struct ctl_table_root *root)
1705 {
1706         spin_lock(&sysctl_lock);
1707         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1708         spin_unlock(&sysctl_lock);
1709 }
1710
1711 #ifdef CONFIG_SYSCTL_SYSCALL
1712 /* Perform the actual read/write of a sysctl table entry. */
1713 static int do_sysctl_strategy(struct ctl_table_root *root,
1714                         struct ctl_table *table,
1715                         void __user *oldval, size_t __user *oldlenp,
1716                         void __user *newval, size_t newlen)
1717 {
1718         int op = 0, rc;
1719
1720         if (oldval)
1721                 op |= MAY_READ;
1722         if (newval)
1723                 op |= MAY_WRITE;
1724         if (sysctl_perm(root, table, op))
1725                 return -EPERM;
1726
1727         if (table->strategy) {
1728                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1729                 if (rc < 0)
1730                         return rc;
1731                 if (rc > 0)
1732                         return 0;
1733         }
1734
1735         /* If there is no strategy routine, or if the strategy returns
1736          * zero, proceed with automatic r/w */
1737         if (table->data && table->maxlen) {
1738                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1739                 if (rc < 0)
1740                         return rc;
1741         }
1742         return 0;
1743 }
1744
1745 static int parse_table(int __user *name, int nlen,
1746                        void __user *oldval, size_t __user *oldlenp,
1747                        void __user *newval, size_t newlen,
1748                        struct ctl_table_root *root,
1749                        struct ctl_table *table)
1750 {
1751         int n;
1752 repeat:
1753         if (!nlen)
1754                 return -ENOTDIR;
1755         if (get_user(n, name))
1756                 return -EFAULT;
1757         for ( ; table->ctl_name || table->procname; table++) {
1758                 if (!table->ctl_name)
1759                         continue;
1760                 if (n == table->ctl_name) {
1761                         int error;
1762                         if (table->child) {
1763                                 if (sysctl_perm(root, table, MAY_EXEC))
1764                                         return -EPERM;
1765                                 name++;
1766                                 nlen--;
1767                                 table = table->child;
1768                                 goto repeat;
1769                         }
1770                         error = do_sysctl_strategy(root, table,
1771                                                    oldval, oldlenp,
1772                                                    newval, newlen);
1773                         return error;
1774                 }
1775         }
1776         return -ENOTDIR;
1777 }
1778
1779 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1780                void __user *newval, size_t newlen)
1781 {
1782         struct ctl_table_header *head;
1783         int error = -ENOTDIR;
1784
1785         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1786                 return -ENOTDIR;
1787         if (oldval) {
1788                 int old_len;
1789                 if (!oldlenp || get_user(old_len, oldlenp))
1790                         return -EFAULT;
1791         }
1792
1793         for (head = sysctl_head_next(NULL); head;
1794                         head = sysctl_head_next(head)) {
1795                 error = parse_table(name, nlen, oldval, oldlenp, 
1796                                         newval, newlen,
1797                                         head->root, head->ctl_table);
1798                 if (error != -ENOTDIR) {
1799                         sysctl_head_finish(head);
1800                         break;
1801                 }
1802         }
1803         return error;
1804 }
1805
1806 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1807 {
1808         struct __sysctl_args tmp;
1809         int error;
1810
1811         if (copy_from_user(&tmp, args, sizeof(tmp)))
1812                 return -EFAULT;
1813
1814         error = deprecated_sysctl_warning(&tmp);
1815         if (error)
1816                 goto out;
1817
1818         lock_kernel();
1819         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1820                           tmp.newval, tmp.newlen);
1821         unlock_kernel();
1822 out:
1823         return error;
1824 }
1825 #endif /* CONFIG_SYSCTL_SYSCALL */
1826
1827 /*
1828  * sysctl_perm does NOT grant the superuser all rights automatically, because
1829  * some sysctl variables are readonly even to root.
1830  */
1831
1832 static int test_perm(int mode, int op)
1833 {
1834         if (!current_euid())
1835                 mode >>= 6;
1836         else if (in_egroup_p(0))
1837                 mode >>= 3;
1838         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1839                 return 0;
1840         return -EACCES;
1841 }
1842
1843 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1844 {
1845         int error;
1846         int mode;
1847
1848         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1849         if (error)
1850                 return error;
1851
1852         if (root->permissions)
1853                 mode = root->permissions(root, current->nsproxy, table);
1854         else
1855                 mode = table->mode;
1856
1857         return test_perm(mode, op);
1858 }
1859
1860 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1861 {
1862         for (; table->ctl_name || table->procname; table++) {
1863                 table->parent = parent;
1864                 if (table->child)
1865                         sysctl_set_parent(table, table->child);
1866         }
1867 }
1868
1869 static __init int sysctl_init(void)
1870 {
1871         sysctl_set_parent(NULL, root_table);
1872 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1873         {
1874                 int err;
1875                 err = sysctl_check_table(current->nsproxy, root_table);
1876         }
1877 #endif
1878         return 0;
1879 }
1880
1881 core_initcall(sysctl_init);
1882
1883 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1884                                       struct ctl_table *table)
1885 {
1886         struct ctl_table *p;
1887         const char *s = branch->procname;
1888
1889         /* branch should have named subdirectory as its first element */
1890         if (!s || !branch->child)
1891                 return NULL;
1892
1893         /* ... and nothing else */
1894         if (branch[1].procname || branch[1].ctl_name)
1895                 return NULL;
1896
1897         /* table should contain subdirectory with the same name */
1898         for (p = table; p->procname || p->ctl_name; p++) {
1899                 if (!p->child)
1900                         continue;
1901                 if (p->procname && strcmp(p->procname, s) == 0)
1902                         return p;
1903         }
1904         return NULL;
1905 }
1906
1907 /* see if attaching q to p would be an improvement */
1908 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1909 {
1910         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1911         struct ctl_table *next;
1912         int is_better = 0;
1913         int not_in_parent = !p->attached_by;
1914
1915         while ((next = is_branch_in(by, to)) != NULL) {
1916                 if (by == q->attached_by)
1917                         is_better = 1;
1918                 if (to == p->attached_by)
1919                         not_in_parent = 1;
1920                 by = by->child;
1921                 to = next->child;
1922         }
1923
1924         if (is_better && not_in_parent) {
1925                 q->attached_by = by;
1926                 q->attached_to = to;
1927                 q->parent = p;
1928         }
1929 }
1930
1931 /**
1932  * __register_sysctl_paths - register a sysctl hierarchy
1933  * @root: List of sysctl headers to register on
1934  * @namespaces: Data to compute which lists of sysctl entries are visible
1935  * @path: The path to the directory the sysctl table is in.
1936  * @table: the top-level table structure
1937  *
1938  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1939  * array. A completely 0 filled entry terminates the table.
1940  *
1941  * The members of the &struct ctl_table structure are used as follows:
1942  *
1943  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1944  *            must be unique within that level of sysctl
1945  *
1946  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1947  *            enter a sysctl file
1948  *
1949  * data - a pointer to data for use by proc_handler
1950  *
1951  * maxlen - the maximum size in bytes of the data
1952  *
1953  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1954  *
1955  * child - a pointer to the child sysctl table if this entry is a directory, or
1956  *         %NULL.
1957  *
1958  * proc_handler - the text handler routine (described below)
1959  *
1960  * strategy - the strategy routine (described below)
1961  *
1962  * de - for internal use by the sysctl routines
1963  *
1964  * extra1, extra2 - extra pointers usable by the proc handler routines
1965  *
1966  * Leaf nodes in the sysctl tree will be represented by a single file
1967  * under /proc; non-leaf nodes will be represented by directories.
1968  *
1969  * sysctl(2) can automatically manage read and write requests through
1970  * the sysctl table.  The data and maxlen fields of the ctl_table
1971  * struct enable minimal validation of the values being written to be
1972  * performed, and the mode field allows minimal authentication.
1973  *
1974  * More sophisticated management can be enabled by the provision of a
1975  * strategy routine with the table entry.  This will be called before
1976  * any automatic read or write of the data is performed.
1977  *
1978  * The strategy routine may return
1979  *
1980  * < 0 - Error occurred (error is passed to user process)
1981  *
1982  * 0   - OK - proceed with automatic read or write.
1983  *
1984  * > 0 - OK - read or write has been done by the strategy routine, so
1985  *       return immediately.
1986  *
1987  * There must be a proc_handler routine for any terminal nodes
1988  * mirrored under /proc/sys (non-terminals are handled by a built-in
1989  * directory handler).  Several default handlers are available to
1990  * cover common cases -
1991  *
1992  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1993  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 
1994  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1995  *
1996  * It is the handler's job to read the input buffer from user memory
1997  * and process it. The handler should return 0 on success.
1998  *
1999  * This routine returns %NULL on a failure to register, and a pointer
2000  * to the table header on success.
2001  */
2002 struct ctl_table_header *__register_sysctl_paths(
2003         struct ctl_table_root *root,
2004         struct nsproxy *namespaces,
2005         const struct ctl_path *path, struct ctl_table *table)
2006 {
2007         struct ctl_table_header *header;
2008         struct ctl_table *new, **prevp;
2009         unsigned int n, npath;
2010         struct ctl_table_set *set;
2011
2012         /* Count the path components */
2013         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
2014                 ;
2015
2016         /*
2017          * For each path component, allocate a 2-element ctl_table array.
2018          * The first array element will be filled with the sysctl entry
2019          * for this, the second will be the sentinel (ctl_name == 0).
2020          *
2021          * We allocate everything in one go so that we don't have to
2022          * worry about freeing additional memory in unregister_sysctl_table.
2023          */
2024         header = kzalloc(sizeof(struct ctl_table_header) +
2025                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
2026         if (!header)
2027                 return NULL;
2028
2029         new = (struct ctl_table *) (header + 1);
2030
2031         /* Now connect the dots */
2032         prevp = &header->ctl_table;
2033         for (n = 0; n < npath; ++n, ++path) {
2034                 /* Copy the procname */
2035                 new->procname = path->procname;
2036                 new->ctl_name = path->ctl_name;
2037                 new->mode     = 0555;
2038
2039                 *prevp = new;
2040                 prevp = &new->child;
2041
2042                 new += 2;
2043         }
2044         *prevp = table;
2045         header->ctl_table_arg = table;
2046
2047         INIT_LIST_HEAD(&header->ctl_entry);
2048         header->used = 0;
2049         header->unregistering = NULL;
2050         header->root = root;
2051         sysctl_set_parent(NULL, header->ctl_table);
2052         header->count = 1;
2053 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2054         if (sysctl_check_table(namespaces, header->ctl_table)) {
2055                 kfree(header);
2056                 return NULL;
2057         }
2058 #endif
2059         spin_lock(&sysctl_lock);
2060         header->set = lookup_header_set(root, namespaces);
2061         header->attached_by = header->ctl_table;
2062         header->attached_to = root_table;
2063         header->parent = &root_table_header;
2064         for (set = header->set; set; set = set->parent) {
2065                 struct ctl_table_header *p;
2066                 list_for_each_entry(p, &set->list, ctl_entry) {
2067                         if (p->unregistering)
2068                                 continue;
2069                         try_attach(p, header);
2070                 }
2071         }
2072         header->parent->count++;
2073         list_add_tail(&header->ctl_entry, &header->set->list);
2074         spin_unlock(&sysctl_lock);
2075
2076         return header;
2077 }
2078
2079 /**
2080  * register_sysctl_table_path - register a sysctl table hierarchy
2081  * @path: The path to the directory the sysctl table is in.
2082  * @table: the top-level table structure
2083  *
2084  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2085  * array. A completely 0 filled entry terminates the table.
2086  *
2087  * See __register_sysctl_paths for more details.
2088  */
2089 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2090                                                 struct ctl_table *table)
2091 {
2092         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2093                                         path, table);
2094 }
2095
2096 /**
2097  * register_sysctl_table - register a sysctl table hierarchy
2098  * @table: the top-level table structure
2099  *
2100  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2101  * array. A completely 0 filled entry terminates the table.
2102  *
2103  * See register_sysctl_paths for more details.
2104  */
2105 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2106 {
2107         static const struct ctl_path null_path[] = { {} };
2108
2109         return register_sysctl_paths(null_path, table);
2110 }
2111
2112 /**
2113  * unregister_sysctl_table - unregister a sysctl table hierarchy
2114  * @header: the header returned from register_sysctl_table
2115  *
2116  * Unregisters the sysctl table and all children. proc entries may not
2117  * actually be removed until they are no longer used by anyone.
2118  */
2119 void unregister_sysctl_table(struct ctl_table_header * header)
2120 {
2121         might_sleep();
2122
2123         if (header == NULL)
2124                 return;
2125
2126         spin_lock(&sysctl_lock);
2127         start_unregistering(header);
2128         if (!--header->parent->count) {
2129                 WARN_ON(1);
2130                 kfree(header->parent);
2131         }
2132         if (!--header->count)
2133                 kfree(header);
2134         spin_unlock(&sysctl_lock);
2135 }
2136
2137 int sysctl_is_seen(struct ctl_table_header *p)
2138 {
2139         struct ctl_table_set *set = p->set;
2140         int res;
2141         spin_lock(&sysctl_lock);
2142         if (p->unregistering)
2143                 res = 0;
2144         else if (!set->is_seen)
2145                 res = 1;
2146         else
2147                 res = set->is_seen(set);
2148         spin_unlock(&sysctl_lock);
2149         return res;
2150 }
2151
2152 void setup_sysctl_set(struct ctl_table_set *p,
2153         struct ctl_table_set *parent,
2154         int (*is_seen)(struct ctl_table_set *))
2155 {
2156         INIT_LIST_HEAD(&p->list);
2157         p->parent = parent ? parent : &sysctl_table_root.default_set;
2158         p->is_seen = is_seen;
2159 }
2160
2161 #else /* !CONFIG_SYSCTL */
2162 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2163 {
2164         return NULL;
2165 }
2166
2167 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2168                                                     struct ctl_table *table)
2169 {
2170         return NULL;
2171 }
2172
2173 void unregister_sysctl_table(struct ctl_table_header * table)
2174 {
2175 }
2176
2177 void setup_sysctl_set(struct ctl_table_set *p,
2178         struct ctl_table_set *parent,
2179         int (*is_seen)(struct ctl_table_set *))
2180 {
2181 }
2182
2183 void sysctl_head_put(struct ctl_table_header *head)
2184 {
2185 }
2186
2187 #endif /* CONFIG_SYSCTL */
2188
2189 /*
2190  * /proc/sys support
2191  */
2192
2193 #ifdef CONFIG_PROC_SYSCTL
2194
2195 static int _proc_do_string(void* data, int maxlen, int write,
2196                            struct file *filp, void __user *buffer,
2197                            size_t *lenp, loff_t *ppos)
2198 {
2199         size_t len;
2200         char __user *p;
2201         char c;
2202
2203         if (!data || !maxlen || !*lenp) {
2204                 *lenp = 0;
2205                 return 0;
2206         }
2207
2208         if (write) {
2209                 len = 0;
2210                 p = buffer;
2211                 while (len < *lenp) {
2212                         if (get_user(c, p++))
2213                                 return -EFAULT;
2214                         if (c == 0 || c == '\n')
2215                                 break;
2216                         len++;
2217                 }
2218                 if (len >= maxlen)
2219                         len = maxlen-1;
2220                 if(copy_from_user(data, buffer, len))
2221                         return -EFAULT;
2222                 ((char *) data)[len] = 0;
2223                 *ppos += *lenp;
2224         } else {
2225                 len = strlen(data);
2226                 if (len > maxlen)
2227                         len = maxlen;
2228
2229                 if (*ppos > len) {
2230                         *lenp = 0;
2231                         return 0;
2232                 }
2233
2234                 data += *ppos;
2235                 len  -= *ppos;
2236
2237                 if (len > *lenp)
2238                         len = *lenp;
2239                 if (len)
2240                         if(copy_to_user(buffer, data, len))
2241                                 return -EFAULT;
2242                 if (len < *lenp) {
2243                         if(put_user('\n', ((char __user *) buffer) + len))
2244                                 return -EFAULT;
2245                         len++;
2246                 }
2247                 *lenp = len;
2248                 *ppos += len;
2249         }
2250         return 0;
2251 }
2252
2253 /**
2254  * proc_dostring - read a string sysctl
2255  * @table: the sysctl table
2256  * @write: %TRUE if this is a write to the sysctl file
2257  * @filp: the file structure
2258  * @buffer: the user buffer
2259  * @lenp: the size of the user buffer
2260  * @ppos: file position
2261  *
2262  * Reads/writes a string from/to the user buffer. If the kernel
2263  * buffer provided is not large enough to hold the string, the
2264  * string is truncated. The copied string is %NULL-terminated.
2265  * If the string is being read by the user process, it is copied
2266  * and a newline '\n' is added. It is truncated if the buffer is
2267  * not large enough.
2268  *
2269  * Returns 0 on success.
2270  */
2271 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2272                   void __user *buffer, size_t *lenp, loff_t *ppos)
2273 {
2274         return _proc_do_string(table->data, table->maxlen, write, filp,
2275                                buffer, lenp, ppos);
2276 }
2277
2278
2279 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2280                                  int *valp,
2281                                  int write, void *data)
2282 {
2283         if (write) {
2284                 *valp = *negp ? -*lvalp : *lvalp;
2285         } else {
2286                 int val = *valp;
2287                 if (val < 0) {
2288                         *negp = -1;
2289                         *lvalp = (unsigned long)-val;
2290                 } else {
2291                         *negp = 0;
2292                         *lvalp = (unsigned long)val;
2293                 }
2294         }
2295         return 0;
2296 }
2297
2298 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2299                   int write, struct file *filp, void __user *buffer,
2300                   size_t *lenp, loff_t *ppos,
2301                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2302                               int write, void *data),
2303                   void *data)
2304 {
2305 #define TMPBUFLEN 21
2306         int *i, vleft, first = 1, neg;
2307         unsigned long lval;
2308         size_t left, len;
2309         
2310         char buf[TMPBUFLEN], *p;
2311         char __user *s = buffer;
2312         
2313         if (!tbl_data || !table->maxlen || !*lenp ||
2314             (*ppos && !write)) {
2315                 *lenp = 0;
2316                 return 0;
2317         }
2318         
2319         i = (int *) tbl_data;
2320         vleft = table->maxlen / sizeof(*i);
2321         left = *lenp;
2322
2323         if (!conv)
2324                 conv = do_proc_dointvec_conv;
2325
2326         for (; left && vleft--; i++, first=0) {
2327                 if (write) {
2328                         while (left) {
2329                                 char c;
2330                                 if (get_user(c, s))
2331                                         return -EFAULT;
2332                                 if (!isspace(c))
2333                                         break;
2334                                 left--;
2335                                 s++;
2336                         }
2337                         if (!left)
2338                                 break;
2339                         neg = 0;
2340                         len = left;
2341                         if (len > sizeof(buf) - 1)
2342                                 len = sizeof(buf) - 1;
2343                         if (copy_from_user(buf, s, len))
2344                                 return -EFAULT;
2345                         buf[len] = 0;
2346                         p = buf;
2347                         if (*p == '-' && left > 1) {
2348                                 neg = 1;
2349                                 p++;
2350                         }
2351                         if (*p < '0' || *p > '9')
2352                                 break;
2353
2354                         lval = simple_strtoul(p, &p, 0);
2355
2356                         len = p-buf;
2357                         if ((len < left) && *p && !isspace(*p))
2358                                 break;
2359                         s += len;
2360                         left -= len;
2361
2362                         if (conv(&neg, &lval, i, 1, data))
2363                                 break;
2364                 } else {
2365                         p = buf;
2366                         if (!first)
2367                                 *p++ = '\t';
2368         
2369                         if (conv(&neg, &lval, i, 0, data))
2370                                 break;
2371
2372                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2373                         len = strlen(buf);
2374                         if (len > left)
2375                                 len = left;
2376                         if(copy_to_user(s, buf, len))
2377                                 return -EFAULT;
2378                         left -= len;
2379                         s += len;
2380                 }
2381         }
2382
2383         if (!write && !first && left) {
2384                 if(put_user('\n', s))
2385                         return -EFAULT;
2386                 left--, s++;
2387         }
2388         if (write) {
2389                 while (left) {
2390                         char c;
2391                         if (get_user(c, s++))
2392                                 return -EFAULT;
2393                         if (!isspace(c))
2394                                 break;
2395                         left--;
2396                 }
2397         }
2398         if (write && first)
2399                 return -EINVAL;
2400         *lenp -= left;
2401         *ppos += *lenp;
2402         return 0;
2403 #undef TMPBUFLEN
2404 }
2405
2406 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2407                   void __user *buffer, size_t *lenp, loff_t *ppos,
2408                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2409                               int write, void *data),
2410                   void *data)
2411 {
2412         return __do_proc_dointvec(table->data, table, write, filp,
2413                         buffer, lenp, ppos, conv, data);
2414 }
2415
2416 /**
2417  * proc_dointvec - read a vector of integers
2418  * @table: the sysctl table
2419  * @write: %TRUE if this is a write to the sysctl file
2420  * @filp: the file structure
2421  * @buffer: the user buffer
2422  * @lenp: the size of the user buffer
2423  * @ppos: file position
2424  *
2425  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2426  * values from/to the user buffer, treated as an ASCII string. 
2427  *
2428  * Returns 0 on success.
2429  */
2430 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2431                      void __user *buffer, size_t *lenp, loff_t *ppos)
2432 {
2433     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2434                             NULL,NULL);
2435 }
2436
2437 /*
2438  * Taint values can only be increased
2439  * This means we can safely use a temporary.
2440  */
2441 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2442                                void __user *buffer, size_t *lenp, loff_t *ppos)
2443 {
2444         struct ctl_table t;
2445         unsigned long tmptaint = get_taint();
2446         int err;
2447
2448         if (write && !capable(CAP_SYS_ADMIN))
2449                 return -EPERM;
2450
2451         t = *table;
2452         t.data = &tmptaint;
2453         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2454         if (err < 0)
2455                 return err;
2456
2457         if (write) {
2458                 /*
2459                  * Poor man's atomic or. Not worth adding a primitive
2460                  * to everyone's atomic.h for this
2461                  */
2462                 int i;
2463                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2464                         if ((tmptaint >> i) & 1)
2465                                 add_taint(i);
2466                 }
2467         }
2468
2469         return err;
2470 }
2471
2472 struct do_proc_dointvec_minmax_conv_param {
2473         int *min;
2474         int *max;
2475 };
2476
2477 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, 
2478                                         int *valp, 
2479                                         int write, void *data)
2480 {
2481         struct do_proc_dointvec_minmax_conv_param *param = data;
2482         if (write) {
2483                 int val = *negp ? -*lvalp : *lvalp;
2484                 if ((param->min && *param->min > val) ||
2485                     (param->max && *param->max < val))
2486                         return -EINVAL;
2487                 *valp = val;
2488         } else {
2489                 int val = *valp;
2490                 if (val < 0) {
2491                         *negp = -1;
2492                         *lvalp = (unsigned long)-val;
2493                 } else {
2494                         *negp = 0;
2495                         *lvalp = (unsigned long)val;
2496                 }
2497         }
2498         return 0;
2499 }
2500
2501 /**
2502  * proc_dointvec_minmax - read a vector of integers with min/max values
2503  * @table: the sysctl table
2504  * @write: %TRUE if this is a write to the sysctl file
2505  * @filp: the file structure
2506  * @buffer: the user buffer
2507  * @lenp: the size of the user buffer
2508  * @ppos: file position
2509  *
2510  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2511  * values from/to the user buffer, treated as an ASCII string.
2512  *
2513  * This routine will ensure the values are within the range specified by
2514  * table->extra1 (min) and table->extra2 (max).
2515  *
2516  * Returns 0 on success.
2517  */
2518 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2519                   void __user *buffer, size_t *lenp, loff_t *ppos)
2520 {
2521         struct do_proc_dointvec_minmax_conv_param param = {
2522                 .min = (int *) table->extra1,
2523                 .max = (int *) table->extra2,
2524         };
2525         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2526                                 do_proc_dointvec_minmax_conv, &param);
2527 }
2528
2529 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2530                                      struct file *filp,
2531                                      void __user *buffer,
2532                                      size_t *lenp, loff_t *ppos,
2533                                      unsigned long convmul,
2534                                      unsigned long convdiv)
2535 {
2536 #define TMPBUFLEN 21
2537         unsigned long *i, *min, *max, val;
2538         int vleft, first=1, neg;
2539         size_t len, left;
2540         char buf[TMPBUFLEN], *p;
2541         char __user *s = buffer;
2542         
2543         if (!data || !table->maxlen || !*lenp ||
2544             (*ppos && !write)) {
2545                 *lenp = 0;
2546                 return 0;
2547         }
2548         
2549         i = (unsigned long *) data;
2550         min = (unsigned long *) table->extra1;
2551         max = (unsigned long *) table->extra2;
2552         vleft = table->maxlen / sizeof(unsigned long);
2553         left = *lenp;
2554         
2555         for (; left && vleft--; i++, min++, max++, first=0) {
2556                 if (write) {
2557                         while (left) {
2558                                 char c;
2559                                 if (get_user(c, s))
2560                                         return -EFAULT;
2561                                 if (!isspace(c))
2562                                         break;
2563                                 left--;
2564                                 s++;
2565                         }
2566                         if (!left)
2567                                 break;
2568                         neg = 0;
2569                         len = left;
2570                         if (len > TMPBUFLEN-1)
2571                                 len = TMPBUFLEN-1;
2572                         if (copy_from_user(buf, s, len))
2573                                 return -EFAULT;
2574                         buf[len] = 0;
2575                         p = buf;
2576                         if (*p == '-' && left > 1) {
2577                                 neg = 1;
2578                                 p++;
2579                         }
2580                         if (*p < '0' || *p > '9')
2581                                 break;
2582                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2583                         len = p-buf;
2584                         if ((len < left) && *p && !isspace(*p))
2585                                 break;
2586                         if (neg)
2587                                 val = -val;
2588                         s += len;
2589                         left -= len;
2590
2591                         if(neg)
2592                                 continue;
2593                         if ((min && val < *min) || (max && val > *max))
2594                                 continue;
2595                         *i = val;
2596                 } else {
2597                         p = buf;
2598                         if (!first)
2599                                 *p++ = '\t';
2600                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2601                         len = strlen(buf);
2602                         if (len > left)
2603                                 len = left;
2604                         if(copy_to_user(s, buf, len))
2605                                 return -EFAULT;
2606                         left -= len;
2607                         s += len;
2608                 }
2609         }
2610
2611         if (!write && !first && left) {
2612                 if(put_user('\n', s))
2613                         return -EFAULT;
2614                 left--, s++;
2615         }
2616         if (write) {
2617                 while (left) {
2618                         char c;
2619                         if (get_user(c, s++))
2620                                 return -EFAULT;
2621                         if (!isspace(c))
2622                                 break;
2623                         left--;
2624                 }
2625         }
2626         if (write && first)
2627                 return -EINVAL;
2628         *lenp -= left;
2629         *ppos += *lenp;
2630         return 0;
2631 #undef TMPBUFLEN
2632 }
2633
2634 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2635                                      struct file *filp,
2636                                      void __user *buffer,
2637                                      size_t *lenp, loff_t *ppos,
2638                                      unsigned long convmul,
2639                                      unsigned long convdiv)
2640 {
2641         return __do_proc_doulongvec_minmax(table->data, table, write,
2642                         filp, buffer, lenp, ppos, convmul, convdiv);
2643 }
2644
2645 /**
2646  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2647  * @table: the sysctl table
2648  * @write: %TRUE if this is a write to the sysctl file
2649  * @filp: the file structure
2650  * @buffer: the user buffer
2651  * @lenp: the size of the user buffer
2652  * @ppos: file position
2653  *
2654  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2655  * values from/to the user buffer, treated as an ASCII string.
2656  *
2657  * This routine will ensure the values are within the range specified by
2658  * table->extra1 (min) and table->extra2 (max).
2659  *
2660  * Returns 0 on success.
2661  */
2662 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2663                            void __user *buffer, size_t *lenp, loff_t *ppos)
2664 {
2665     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2666 }
2667
2668 /**
2669  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2670  * @table: the sysctl table
2671  * @write: %TRUE if this is a write to the sysctl file
2672  * @filp: the file structure
2673  * @buffer: the user buffer
2674  * @lenp: the size of the user buffer
2675  * @ppos: file position
2676  *
2677  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2678  * values from/to the user buffer, treated as an ASCII string. The values
2679  * are treated as milliseconds, and converted to jiffies when they are stored.
2680  *
2681  * This routine will ensure the values are within the range specified by
2682  * table->extra1 (min) and table->extra2 (max).
2683  *
2684  * Returns 0 on success.
2685  */
2686 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2687                                       struct file *filp,
2688                                       void __user *buffer,
2689                                       size_t *lenp, loff_t *ppos)
2690 {
2691     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2692                                      lenp, ppos, HZ, 1000l);
2693 }
2694
2695
2696 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2697                                          int *valp,
2698                                          int write, void *data)
2699 {
2700         if (write) {
2701                 if (*lvalp > LONG_MAX / HZ)
2702                         return 1;
2703                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2704         } else {
2705                 int val = *valp;
2706                 unsigned long lval;
2707                 if (val < 0) {
2708                         *negp = -1;
2709                         lval = (unsigned long)-val;
2710                 } else {
2711                         *negp = 0;
2712                         lval = (unsigned long)val;
2713                 }
2714                 *lvalp = lval / HZ;
2715         }
2716         return 0;
2717 }
2718
2719 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2720                                                 int *valp,
2721                                                 int write, void *data)
2722 {
2723         if (write) {
2724                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2725                         return 1;
2726                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2727         } else {
2728                 int val = *valp;
2729                 unsigned long lval;
2730                 if (val < 0) {
2731                         *negp = -1;
2732                         lval = (unsigned long)-val;
2733                 } else {
2734                         *negp = 0;
2735                         lval = (unsigned long)val;
2736                 }
2737                 *lvalp = jiffies_to_clock_t(lval);
2738         }
2739         return 0;
2740 }
2741
2742 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2743                                             int *valp,
2744                                             int write, void *data)
2745 {
2746         if (write) {
2747                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2748         } else {
2749                 int val = *valp;
2750                 unsigned long lval;
2751                 if (val < 0) {
2752                         *negp = -1;
2753                         lval = (unsigned long)-val;
2754                 } else {
2755                         *negp = 0;
2756                         lval = (unsigned long)val;
2757                 }
2758                 *lvalp = jiffies_to_msecs(lval);
2759         }
2760         return 0;
2761 }
2762
2763 /**
2764  * proc_dointvec_jiffies - read a vector of integers as seconds
2765  * @table: the sysctl table
2766  * @write: %TRUE if this is a write to the sysctl file
2767  * @filp: the file structure
2768  * @buffer: the user buffer
2769  * @lenp: the size of the user buffer
2770  * @ppos: file position
2771  *
2772  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2773  * values from/to the user buffer, treated as an ASCII string. 
2774  * The values read are assumed to be in seconds, and are converted into
2775  * jiffies.
2776  *
2777  * Returns 0 on success.
2778  */
2779 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2780                           void __user *buffer, size_t *lenp, loff_t *ppos)
2781 {
2782     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2783                             do_proc_dointvec_jiffies_conv,NULL);
2784 }
2785
2786 /**
2787  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2788  * @table: the sysctl table
2789  * @write: %TRUE if this is a write to the sysctl file
2790  * @filp: the file structure
2791  * @buffer: the user buffer
2792  * @lenp: the size of the user buffer
2793  * @ppos: pointer to the file position
2794  *
2795  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2796  * values from/to the user buffer, treated as an ASCII string. 
2797  * The values read are assumed to be in 1/USER_HZ seconds, and 
2798  * are converted into jiffies.
2799  *
2800  * Returns 0 on success.
2801  */
2802 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2803                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2804 {
2805     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2806                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2807 }
2808
2809 /**
2810  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2811  * @table: the sysctl table
2812  * @write: %TRUE if this is a write to the sysctl file
2813  * @filp: the file structure
2814  * @buffer: the user buffer
2815  * @lenp: the size of the user buffer
2816  * @ppos: file position
2817  * @ppos: the current position in the file
2818  *
2819  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2820  * values from/to the user buffer, treated as an ASCII string. 
2821  * The values read are assumed to be in 1/1000 seconds, and 
2822  * are converted into jiffies.
2823  *
2824  * Returns 0 on success.
2825  */
2826 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2827                              void __user *buffer, size_t *lenp, loff_t *ppos)
2828 {
2829         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2830                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2831 }
2832
2833 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2834                            void __user *buffer, size_t *lenp, loff_t *ppos)
2835 {
2836         struct pid *new_pid;
2837         pid_t tmp;
2838         int r;
2839
2840         tmp = pid_vnr(cad_pid);
2841
2842         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2843                                lenp, ppos, NULL, NULL);
2844         if (r || !write)
2845                 return r;
2846
2847         new_pid = find_get_pid(tmp);
2848         if (!new_pid)
2849                 return -ESRCH;
2850
2851         put_pid(xchg(&cad_pid, new_pid));
2852         return 0;
2853 }
2854
2855 #else /* CONFIG_PROC_FS */
2856
2857 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2858                   void __user *buffer, size_t *lenp, loff_t *ppos)
2859 {
2860         return -ENOSYS;
2861 }
2862
2863 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2864                   void __user *buffer, size_t *lenp, loff_t *ppos)
2865 {
2866         return -ENOSYS;
2867 }
2868
2869 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2870                     void __user *buffer, size_t *lenp, loff_t *ppos)
2871 {
2872         return -ENOSYS;
2873 }
2874
2875 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2876                     void __user *buffer, size_t *lenp, loff_t *ppos)
2877 {
2878         return -ENOSYS;
2879 }
2880
2881 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2882                     void __user *buffer, size_t *lenp, loff_t *ppos)
2883 {
2884         return -ENOSYS;
2885 }
2886
2887 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2888                              void __user *buffer, size_t *lenp, loff_t *ppos)
2889 {
2890         return -ENOSYS;
2891 }
2892
2893 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2894                     void __user *buffer, size_t *lenp, loff_t *ppos)
2895 {
2896         return -ENOSYS;
2897 }
2898
2899 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2900                                       struct file *filp,
2901                                       void __user *buffer,
2902                                       size_t *lenp, loff_t *ppos)
2903 {
2904     return -ENOSYS;
2905 }
2906
2907
2908 #endif /* CONFIG_PROC_FS */
2909
2910
2911 #ifdef CONFIG_SYSCTL_SYSCALL
2912 /*
2913  * General sysctl support routines 
2914  */
2915
2916 /* The generic sysctl data routine (used if no strategy routine supplied) */
2917 int sysctl_data(struct ctl_table *table,
2918                 void __user *oldval, size_t __user *oldlenp,
2919                 void __user *newval, size_t newlen)
2920 {
2921         size_t len;
2922
2923         /* Get out of I don't have a variable */
2924         if (!table->data || !table->maxlen)
2925                 return -ENOTDIR;
2926
2927         if (oldval && oldlenp) {
2928                 if (get_user(len, oldlenp))
2929                         return -EFAULT;
2930                 if (len) {
2931                         if (len > table->maxlen)
2932                                 len = table->maxlen;
2933                         if (copy_to_user(oldval, table->data, len))
2934                                 return -EFAULT;
2935                         if (put_user(len, oldlenp))
2936                                 return -EFAULT;
2937                 }
2938         }
2939
2940         if (newval && newlen) {
2941                 if (newlen > table->maxlen)
2942                         newlen = table->maxlen;
2943
2944                 if (copy_from_user(table->data, newval, newlen))
2945                         return -EFAULT;
2946         }
2947         return 1;
2948 }
2949
2950 /* The generic string strategy routine: */
2951 int sysctl_string(struct ctl_table *table,
2952                   void __user *oldval, size_t __user *oldlenp,
2953                   void __user *newval, size_t newlen)
2954 {
2955         if (!table->data || !table->maxlen) 
2956                 return -ENOTDIR;
2957         
2958         if (oldval && oldlenp) {
2959                 size_t bufsize;
2960                 if (get_user(bufsize, oldlenp))
2961                         return -EFAULT;
2962                 if (bufsize) {
2963                         size_t len = strlen(table->data), copied;
2964
2965                         /* This shouldn't trigger for a well-formed sysctl */
2966                         if (len > table->maxlen)
2967                                 len = table->maxlen;
2968
2969                         /* Copy up to a max of bufsize-1 bytes of the string */
2970                         copied = (len >= bufsize) ? bufsize - 1 : len;
2971
2972                         if (copy_to_user(oldval, table->data, copied) ||
2973                             put_user(0, (char __user *)(oldval + copied)))
2974                                 return -EFAULT;
2975                         if (put_user(len, oldlenp))
2976                                 return -EFAULT;
2977                 }
2978         }
2979         if (newval && newlen) {
2980                 size_t len = newlen;
2981                 if (len > table->maxlen)
2982                         len = table->maxlen;
2983                 if(copy_from_user(table->data, newval, len))
2984                         return -EFAULT;
2985                 if (len == table->maxlen)
2986                         len--;
2987                 ((char *) table->data)[len] = 0;
2988         }
2989         return 1;
2990 }
2991
2992 /*
2993  * This function makes sure that all of the integers in the vector
2994  * are between the minimum and maximum values given in the arrays
2995  * table->extra1 and table->extra2, respectively.
2996  */
2997 int sysctl_intvec(struct ctl_table *table,
2998                 void __user *oldval, size_t __user *oldlenp,
2999                 void __user *newval, size_t newlen)
3000 {
3001
3002         if (newval && newlen) {
3003                 int __user *vec = (int __user *) newval;
3004                 int *min = (int *) table->extra1;
3005                 int *max = (int *) table->extra2;
3006                 size_t length;
3007                 int i;
3008
3009                 if (newlen % sizeof(int) != 0)
3010                         return -EINVAL;
3011
3012                 if (!table->extra1 && !table->extra2)
3013                         return 0;
3014
3015                 if (newlen > table->maxlen)
3016                         newlen = table->maxlen;
3017                 length = newlen / sizeof(int);
3018
3019                 for (i = 0; i < length; i++) {
3020                         int value;
3021                         if (get_user(value, vec + i))
3022                                 return -EFAULT;
3023                         if (min && value < min[i])
3024                                 return -EINVAL;
3025                         if (max && value > max[i])
3026                                 return -EINVAL;
3027                 }
3028         }
3029         return 0;
3030 }
3031
3032 /* Strategy function to convert jiffies to seconds */ 
3033 int sysctl_jiffies(struct ctl_table *table,
3034                 void __user *oldval, size_t __user *oldlenp,
3035                 void __user *newval, size_t newlen)
3036 {
3037         if (oldval && oldlenp) {
3038                 size_t olen;
3039
3040                 if (get_user(olen, oldlenp))
3041                         return -EFAULT;
3042                 if (olen) {
3043                         int val;
3044
3045                         if (olen < sizeof(int))
3046                                 return -EINVAL;
3047
3048                         val = *(int *)(table->data) / HZ;
3049                         if (put_user(val, (int __user *)oldval))
3050                                 return -EFAULT;
3051                         if (put_user(sizeof(int), oldlenp))
3052                                 return -EFAULT;
3053                 }
3054         }
3055         if (newval && newlen) { 
3056                 int new;
3057                 if (newlen != sizeof(int))
3058                         return -EINVAL; 
3059                 if (get_user(new, (int __user *)newval))
3060                         return -EFAULT;
3061                 *(int *)(table->data) = new*HZ; 
3062         }
3063         return 1;
3064 }
3065
3066 /* Strategy function to convert jiffies to seconds */ 
3067 int sysctl_ms_jiffies(struct ctl_table *table,
3068                 void __user *oldval, size_t __user *oldlenp,
3069                 void __user *newval, size_t newlen)
3070 {
3071         if (oldval && oldlenp) {
3072                 size_t olen;
3073
3074                 if (get_user(olen, oldlenp))
3075                         return -EFAULT;
3076                 if (olen) {
3077                         int val;
3078
3079                         if (olen < sizeof(int))
3080                                 return -EINVAL;
3081
3082                         val = jiffies_to_msecs(*(int *)(table->data));
3083                         if (put_user(val, (int __user *)oldval))
3084                                 return -EFAULT;
3085                         if (put_user(sizeof(int), oldlenp))
3086                                 return -EFAULT;
3087                 }
3088         }
3089         if (newval && newlen) { 
3090                 int new;
3091                 if (newlen != sizeof(int))
3092                         return -EINVAL; 
3093                 if (get_user(new, (int __user *)newval))
3094                         return -EFAULT;
3095                 *(int *)(table->data) = msecs_to_jiffies(new);
3096         }
3097         return 1;
3098 }
3099
3100
3101
3102 #else /* CONFIG_SYSCTL_SYSCALL */
3103
3104
3105 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3106 {
3107         struct __sysctl_args tmp;
3108         int error;
3109
3110         if (copy_from_user(&tmp, args, sizeof(tmp)))
3111                 return -EFAULT;
3112
3113         error = deprecated_sysctl_warning(&tmp);
3114
3115         /* If no error reading the parameters then just -ENOSYS ... */
3116         if (!error)
3117                 error = -ENOSYS;
3118
3119         return error;
3120 }
3121
3122 int sysctl_data(struct ctl_table *table,
3123                   void __user *oldval, size_t __user *oldlenp,
3124                   void __user *newval, size_t newlen)
3125 {
3126         return -ENOSYS;
3127 }
3128
3129 int sysctl_string(struct ctl_table *table,
3130                   void __user *oldval, size_t __user *oldlenp,
3131                   void __user *newval, size_t newlen)
3132 {
3133         return -ENOSYS;
3134 }
3135
3136 int sysctl_intvec(struct ctl_table *table,
3137                 void __user *oldval, size_t __user *oldlenp,
3138                 void __user *newval, size_t newlen)
3139 {
3140         return -ENOSYS;
3141 }
3142
3143 int sysctl_jiffies(struct ctl_table *table,
3144                 void __user *oldval, size_t __user *oldlenp,
3145                 void __user *newval, size_t newlen)
3146 {
3147         return -ENOSYS;
3148 }
3149
3150 int sysctl_ms_jiffies(struct ctl_table *table,
3151                 void __user *oldval, size_t __user *oldlenp,
3152                 void __user *newval, size_t newlen)
3153 {
3154         return -ENOSYS;
3155 }
3156
3157 #endif /* CONFIG_SYSCTL_SYSCALL */
3158
3159 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3160 {
3161         static int msg_count;
3162         int name[CTL_MAXNAME];
3163         int i;
3164
3165         /* Check args->nlen. */
3166         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3167                 return -ENOTDIR;
3168
3169         /* Read in the sysctl name for better debug message logging */
3170         for (i = 0; i < args->nlen; i++)
3171                 if (get_user(name[i], args->name + i))
3172                         return -EFAULT;
3173
3174         /* Ignore accesses to kernel.version */
3175         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3176                 return 0;
3177
3178         if (msg_count < 5) {
3179                 msg_count++;
3180                 printk(KERN_INFO
3181                         "warning: process `%s' used the deprecated sysctl "
3182                         "system call with ", current->comm);
3183                 for (i = 0; i < args->nlen; i++)
3184                         printk("%d.", name[i]);
3185                 printk("\n");
3186         }
3187         return 0;
3188 }
3189
3190 /*
3191  * No sense putting this after each symbol definition, twice,
3192  * exception granted :-)
3193  */
3194 EXPORT_SYMBOL(proc_dointvec);
3195 EXPORT_SYMBOL(proc_dointvec_jiffies);
3196 EXPORT_SYMBOL(proc_dointvec_minmax);
3197 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3198 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3199 EXPORT_SYMBOL(proc_dostring);
3200 EXPORT_SYMBOL(proc_doulongvec_minmax);
3201 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3202 EXPORT_SYMBOL(register_sysctl_table);
3203 EXPORT_SYMBOL(register_sysctl_paths);
3204 EXPORT_SYMBOL(sysctl_intvec);
3205 EXPORT_SYMBOL(sysctl_jiffies);
3206 EXPORT_SYMBOL(sysctl_ms_jiffies);
3207 EXPORT_SYMBOL(sysctl_string);
3208 EXPORT_SYMBOL(sysctl_data);
3209 EXPORT_SYMBOL(unregister_sysctl_table);