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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/capability.h>
28 #include <linux/ctype.h>
29 #include <linux/utsname.h>
30 #include <linux/smp_lock.h>
31 #include <linux/fs.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/hugetlb.h>
40 #include <linux/security.h>
41 #include <linux/initrd.h>
42 #include <linux/times.h>
43 #include <linux/limits.h>
44 #include <linux/dcache.h>
45 #include <linux/syscalls.h>
46 #include <linux/nfs_fs.h>
47 #include <linux/acpi.h>
48 #include <linux/reboot.h>
49
50 #include <asm/uaccess.h>
51 #include <asm/processor.h>
52
53 #ifdef CONFIG_X86
54 #include <asm/nmi.h>
55 #include <asm/stacktrace.h>
56 #endif
57
58 #if defined(CONFIG_SYSCTL)
59
60 /* External variables not in a header file. */
61 extern int C_A_D;
62 extern int print_fatal_signals;
63 extern int sysctl_overcommit_memory;
64 extern int sysctl_overcommit_ratio;
65 extern int sysctl_panic_on_oom;
66 extern int max_threads;
67 extern int core_uses_pid;
68 extern int suid_dumpable;
69 extern char core_pattern[];
70 extern int pid_max;
71 extern int min_free_kbytes;
72 extern int printk_ratelimit_jiffies;
73 extern int printk_ratelimit_burst;
74 extern int pid_max_min, pid_max_max;
75 extern int sysctl_drop_caches;
76 extern int percpu_pagelist_fraction;
77 extern int compat_log;
78 extern int maps_protect;
79 extern int sysctl_stat_interval;
80 extern int audit_argv_kb;
81
82 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
83 static int maxolduid = 65535;
84 static int minolduid;
85 static int min_percpu_pagelist_fract = 8;
86
87 static int ngroups_max = NGROUPS_MAX;
88
89 #ifdef CONFIG_KMOD
90 extern char modprobe_path[];
91 #endif
92 #ifdef CONFIG_CHR_DEV_SG
93 extern int sg_big_buff;
94 #endif
95
96 #ifdef __sparc__
97 extern char reboot_command [];
98 extern int stop_a_enabled;
99 extern int scons_pwroff;
100 #endif
101
102 #ifdef __hppa__
103 extern int pwrsw_enabled;
104 extern int unaligned_enabled;
105 #endif
106
107 #ifdef CONFIG_S390
108 #ifdef CONFIG_MATHEMU
109 extern int sysctl_ieee_emulation_warnings;
110 #endif
111 extern int sysctl_userprocess_debug;
112 extern int spin_retry;
113 #endif
114
115 extern int sysctl_hz_timer;
116
117 #ifdef CONFIG_BSD_PROCESS_ACCT
118 extern int acct_parm[];
119 #endif
120
121 #ifdef CONFIG_IA64
122 extern int no_unaligned_warning;
123 #endif
124
125 #ifdef CONFIG_RT_MUTEXES
126 extern int max_lock_depth;
127 #endif
128
129 #ifdef CONFIG_SYSCTL_SYSCALL
130 static int parse_table(int __user *, int, void __user *, size_t __user *,
131                 void __user *, size_t, ctl_table *);
132 #endif
133
134
135 #ifdef CONFIG_PROC_SYSCTL
136 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
137                   void __user *buffer, size_t *lenp, loff_t *ppos);
138 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
139                                void __user *buffer, size_t *lenp, loff_t *ppos);
140 #endif
141
142 static ctl_table root_table[];
143 static struct ctl_table_header root_table_header =
144         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
145
146 static ctl_table kern_table[];
147 static ctl_table vm_table[];
148 static ctl_table fs_table[];
149 static ctl_table debug_table[];
150 static ctl_table dev_table[];
151 extern ctl_table random_table[];
152 #ifdef CONFIG_UNIX98_PTYS
153 extern ctl_table pty_table[];
154 #endif
155 #ifdef CONFIG_INOTIFY_USER
156 extern ctl_table inotify_table[];
157 #endif
158
159 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
160 int sysctl_legacy_va_layout;
161 #endif
162
163 extern int prove_locking;
164 extern int lock_stat;
165
166 /* The default sysctl tables: */
167
168 static ctl_table root_table[] = {
169         {
170                 .ctl_name       = CTL_KERN,
171                 .procname       = "kernel",
172                 .mode           = 0555,
173                 .child          = kern_table,
174         },
175         {
176                 .ctl_name       = CTL_VM,
177                 .procname       = "vm",
178                 .mode           = 0555,
179                 .child          = vm_table,
180         },
181 #ifdef CONFIG_NET
182         {
183                 .ctl_name       = CTL_NET,
184                 .procname       = "net",
185                 .mode           = 0555,
186                 .child          = net_table,
187         },
188 #endif
189         {
190                 .ctl_name       = CTL_FS,
191                 .procname       = "fs",
192                 .mode           = 0555,
193                 .child          = fs_table,
194         },
195         {
196                 .ctl_name       = CTL_DEBUG,
197                 .procname       = "debug",
198                 .mode           = 0555,
199                 .child          = debug_table,
200         },
201         {
202                 .ctl_name       = CTL_DEV,
203                 .procname       = "dev",
204                 .mode           = 0555,
205                 .child          = dev_table,
206         },
207 /*
208  * NOTE: do not add new entries to this table unless you have read
209  * Documentation/sysctl/ctl_unnumbered.txt
210  */
211         { .ctl_name = 0 }
212 };
213
214 #ifdef CONFIG_SCHED_DEBUG
215 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
216 static unsigned long max_sched_granularity_ns = 1000000000;     /* 1 second */
217 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
218 static unsigned long max_wakeup_granularity_ns = 1000000000;    /* 1 second */
219 #endif
220
221 static ctl_table kern_table[] = {
222 #ifdef CONFIG_SCHED_DEBUG
223         {
224                 .ctl_name       = CTL_UNNUMBERED,
225                 .procname       = "sched_nr_latency",
226                 .data           = &sysctl_sched_nr_latency,
227                 .maxlen         = sizeof(unsigned int),
228                 .mode           = 0644,
229                 .proc_handler   = &proc_dointvec,
230         },
231         {
232                 .ctl_name       = CTL_UNNUMBERED,
233                 .procname       = "sched_latency_ns",
234                 .data           = &sysctl_sched_latency,
235                 .maxlen         = sizeof(unsigned int),
236                 .mode           = 0644,
237                 .proc_handler   = &proc_dointvec_minmax,
238                 .strategy       = &sysctl_intvec,
239                 .extra1         = &min_sched_granularity_ns,
240                 .extra2         = &max_sched_granularity_ns,
241         },
242         {
243                 .ctl_name       = CTL_UNNUMBERED,
244                 .procname       = "sched_wakeup_granularity_ns",
245                 .data           = &sysctl_sched_wakeup_granularity,
246                 .maxlen         = sizeof(unsigned int),
247                 .mode           = 0644,
248                 .proc_handler   = &proc_dointvec_minmax,
249                 .strategy       = &sysctl_intvec,
250                 .extra1         = &min_wakeup_granularity_ns,
251                 .extra2         = &max_wakeup_granularity_ns,
252         },
253         {
254                 .ctl_name       = CTL_UNNUMBERED,
255                 .procname       = "sched_batch_wakeup_granularity_ns",
256                 .data           = &sysctl_sched_batch_wakeup_granularity,
257                 .maxlen         = sizeof(unsigned int),
258                 .mode           = 0644,
259                 .proc_handler   = &proc_dointvec_minmax,
260                 .strategy       = &sysctl_intvec,
261                 .extra1         = &min_wakeup_granularity_ns,
262                 .extra2         = &max_wakeup_granularity_ns,
263         },
264         {
265                 .ctl_name       = CTL_UNNUMBERED,
266                 .procname       = "sched_child_runs_first",
267                 .data           = &sysctl_sched_child_runs_first,
268                 .maxlen         = sizeof(unsigned int),
269                 .mode           = 0644,
270                 .proc_handler   = &proc_dointvec,
271         },
272         {
273                 .ctl_name       = CTL_UNNUMBERED,
274                 .procname       = "sched_features",
275                 .data           = &sysctl_sched_features,
276                 .maxlen         = sizeof(unsigned int),
277                 .mode           = 0644,
278                 .proc_handler   = &proc_dointvec,
279         },
280         {
281                 .ctl_name       = CTL_UNNUMBERED,
282                 .procname       = "sched_migration_cost",
283                 .data           = &sysctl_sched_migration_cost,
284                 .maxlen         = sizeof(unsigned int),
285                 .mode           = 0644,
286                 .proc_handler   = &proc_dointvec,
287         },
288 #endif
289         {
290                 .ctl_name       = CTL_UNNUMBERED,
291                 .procname       = "sched_compat_yield",
292                 .data           = &sysctl_sched_compat_yield,
293                 .maxlen         = sizeof(unsigned int),
294                 .mode           = 0644,
295                 .proc_handler   = &proc_dointvec,
296         },
297 #ifdef CONFIG_PROVE_LOCKING
298         {
299                 .ctl_name       = CTL_UNNUMBERED,
300                 .procname       = "prove_locking",
301                 .data           = &prove_locking,
302                 .maxlen         = sizeof(int),
303                 .mode           = 0644,
304                 .proc_handler   = &proc_dointvec,
305         },
306 #endif
307 #ifdef CONFIG_LOCK_STAT
308         {
309                 .ctl_name       = CTL_UNNUMBERED,
310                 .procname       = "lock_stat",
311                 .data           = &lock_stat,
312                 .maxlen         = sizeof(int),
313                 .mode           = 0644,
314                 .proc_handler   = &proc_dointvec,
315         },
316 #endif
317         {
318                 .ctl_name       = KERN_PANIC,
319                 .procname       = "panic",
320                 .data           = &panic_timeout,
321                 .maxlen         = sizeof(int),
322                 .mode           = 0644,
323                 .proc_handler   = &proc_dointvec,
324         },
325         {
326                 .ctl_name       = KERN_CORE_USES_PID,
327                 .procname       = "core_uses_pid",
328                 .data           = &core_uses_pid,
329                 .maxlen         = sizeof(int),
330                 .mode           = 0644,
331                 .proc_handler   = &proc_dointvec,
332         },
333 #ifdef CONFIG_AUDITSYSCALL
334         {
335                 .ctl_name       = CTL_UNNUMBERED,
336                 .procname       = "audit_argv_kb",
337                 .data           = &audit_argv_kb,
338                 .maxlen         = sizeof(int),
339                 .mode           = 0644,
340                 .proc_handler   = &proc_dointvec,
341         },
342 #endif
343         {
344                 .ctl_name       = KERN_CORE_PATTERN,
345                 .procname       = "core_pattern",
346                 .data           = core_pattern,
347                 .maxlen         = CORENAME_MAX_SIZE,
348                 .mode           = 0644,
349                 .proc_handler   = &proc_dostring,
350                 .strategy       = &sysctl_string,
351         },
352 #ifdef CONFIG_PROC_SYSCTL
353         {
354                 .ctl_name       = KERN_TAINTED,
355                 .procname       = "tainted",
356                 .data           = &tainted,
357                 .maxlen         = sizeof(int),
358                 .mode           = 0644,
359                 .proc_handler   = &proc_dointvec_taint,
360         },
361 #endif
362         {
363                 .ctl_name       = KERN_CAP_BSET,
364                 .procname       = "cap-bound",
365                 .data           = &cap_bset,
366                 .maxlen         = sizeof(kernel_cap_t),
367                 .mode           = 0600,
368                 .proc_handler   = &proc_dointvec_bset,
369         },
370 #ifdef CONFIG_BLK_DEV_INITRD
371         {
372                 .ctl_name       = KERN_REALROOTDEV,
373                 .procname       = "real-root-dev",
374                 .data           = &real_root_dev,
375                 .maxlen         = sizeof(int),
376                 .mode           = 0644,
377                 .proc_handler   = &proc_dointvec,
378         },
379 #endif
380         {
381                 .ctl_name       = CTL_UNNUMBERED,
382                 .procname       = "print-fatal-signals",
383                 .data           = &print_fatal_signals,
384                 .maxlen         = sizeof(int),
385                 .mode           = 0644,
386                 .proc_handler   = &proc_dointvec,
387         },
388 #ifdef __sparc__
389         {
390                 .ctl_name       = KERN_SPARC_REBOOT,
391                 .procname       = "reboot-cmd",
392                 .data           = reboot_command,
393                 .maxlen         = 256,
394                 .mode           = 0644,
395                 .proc_handler   = &proc_dostring,
396                 .strategy       = &sysctl_string,
397         },
398         {
399                 .ctl_name       = KERN_SPARC_STOP_A,
400                 .procname       = "stop-a",
401                 .data           = &stop_a_enabled,
402                 .maxlen         = sizeof (int),
403                 .mode           = 0644,
404                 .proc_handler   = &proc_dointvec,
405         },
406         {
407                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
408                 .procname       = "scons-poweroff",
409                 .data           = &scons_pwroff,
410                 .maxlen         = sizeof (int),
411                 .mode           = 0644,
412                 .proc_handler   = &proc_dointvec,
413         },
414 #endif
415 #ifdef __hppa__
416         {
417                 .ctl_name       = KERN_HPPA_PWRSW,
418                 .procname       = "soft-power",
419                 .data           = &pwrsw_enabled,
420                 .maxlen         = sizeof (int),
421                 .mode           = 0644,
422                 .proc_handler   = &proc_dointvec,
423         },
424         {
425                 .ctl_name       = KERN_HPPA_UNALIGNED,
426                 .procname       = "unaligned-trap",
427                 .data           = &unaligned_enabled,
428                 .maxlen         = sizeof (int),
429                 .mode           = 0644,
430                 .proc_handler   = &proc_dointvec,
431         },
432 #endif
433         {
434                 .ctl_name       = KERN_CTLALTDEL,
435                 .procname       = "ctrl-alt-del",
436                 .data           = &C_A_D,
437                 .maxlen         = sizeof(int),
438                 .mode           = 0644,
439                 .proc_handler   = &proc_dointvec,
440         },
441         {
442                 .ctl_name       = KERN_PRINTK,
443                 .procname       = "printk",
444                 .data           = &console_loglevel,
445                 .maxlen         = 4*sizeof(int),
446                 .mode           = 0644,
447                 .proc_handler   = &proc_dointvec,
448         },
449 #ifdef CONFIG_KMOD
450         {
451                 .ctl_name       = KERN_MODPROBE,
452                 .procname       = "modprobe",
453                 .data           = &modprobe_path,
454                 .maxlen         = KMOD_PATH_LEN,
455                 .mode           = 0644,
456                 .proc_handler   = &proc_dostring,
457                 .strategy       = &sysctl_string,
458         },
459 #endif
460 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
461         {
462                 .ctl_name       = KERN_HOTPLUG,
463                 .procname       = "hotplug",
464                 .data           = &uevent_helper,
465                 .maxlen         = UEVENT_HELPER_PATH_LEN,
466                 .mode           = 0644,
467                 .proc_handler   = &proc_dostring,
468                 .strategy       = &sysctl_string,
469         },
470 #endif
471 #ifdef CONFIG_CHR_DEV_SG
472         {
473                 .ctl_name       = KERN_SG_BIG_BUFF,
474                 .procname       = "sg-big-buff",
475                 .data           = &sg_big_buff,
476                 .maxlen         = sizeof (int),
477                 .mode           = 0444,
478                 .proc_handler   = &proc_dointvec,
479         },
480 #endif
481 #ifdef CONFIG_BSD_PROCESS_ACCT
482         {
483                 .ctl_name       = KERN_ACCT,
484                 .procname       = "acct",
485                 .data           = &acct_parm,
486                 .maxlen         = 3*sizeof(int),
487                 .mode           = 0644,
488                 .proc_handler   = &proc_dointvec,
489         },
490 #endif
491 #ifdef CONFIG_MAGIC_SYSRQ
492         {
493                 .ctl_name       = KERN_SYSRQ,
494                 .procname       = "sysrq",
495                 .data           = &__sysrq_enabled,
496                 .maxlen         = sizeof (int),
497                 .mode           = 0644,
498                 .proc_handler   = &proc_dointvec,
499         },
500 #endif
501 #ifdef CONFIG_PROC_SYSCTL
502         {
503                 .ctl_name       = KERN_CADPID,
504                 .procname       = "cad_pid",
505                 .data           = NULL,
506                 .maxlen         = sizeof (int),
507                 .mode           = 0600,
508                 .proc_handler   = &proc_do_cad_pid,
509         },
510 #endif
511         {
512                 .ctl_name       = KERN_MAX_THREADS,
513                 .procname       = "threads-max",
514                 .data           = &max_threads,
515                 .maxlen         = sizeof(int),
516                 .mode           = 0644,
517                 .proc_handler   = &proc_dointvec,
518         },
519         {
520                 .ctl_name       = KERN_RANDOM,
521                 .procname       = "random",
522                 .mode           = 0555,
523                 .child          = random_table,
524         },
525 #ifdef CONFIG_UNIX98_PTYS
526         {
527                 .ctl_name       = KERN_PTY,
528                 .procname       = "pty",
529                 .mode           = 0555,
530                 .child          = pty_table,
531         },
532 #endif
533         {
534                 .ctl_name       = KERN_OVERFLOWUID,
535                 .procname       = "overflowuid",
536                 .data           = &overflowuid,
537                 .maxlen         = sizeof(int),
538                 .mode           = 0644,
539                 .proc_handler   = &proc_dointvec_minmax,
540                 .strategy       = &sysctl_intvec,
541                 .extra1         = &minolduid,
542                 .extra2         = &maxolduid,
543         },
544         {
545                 .ctl_name       = KERN_OVERFLOWGID,
546                 .procname       = "overflowgid",
547                 .data           = &overflowgid,
548                 .maxlen         = sizeof(int),
549                 .mode           = 0644,
550                 .proc_handler   = &proc_dointvec_minmax,
551                 .strategy       = &sysctl_intvec,
552                 .extra1         = &minolduid,
553                 .extra2         = &maxolduid,
554         },
555 #ifdef CONFIG_S390
556 #ifdef CONFIG_MATHEMU
557         {
558                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
559                 .procname       = "ieee_emulation_warnings",
560                 .data           = &sysctl_ieee_emulation_warnings,
561                 .maxlen         = sizeof(int),
562                 .mode           = 0644,
563                 .proc_handler   = &proc_dointvec,
564         },
565 #endif
566 #ifdef CONFIG_NO_IDLE_HZ
567         {
568                 .ctl_name       = KERN_HZ_TIMER,
569                 .procname       = "hz_timer",
570                 .data           = &sysctl_hz_timer,
571                 .maxlen         = sizeof(int),
572                 .mode           = 0644,
573                 .proc_handler   = &proc_dointvec,
574         },
575 #endif
576         {
577                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
578                 .procname       = "userprocess_debug",
579                 .data           = &sysctl_userprocess_debug,
580                 .maxlen         = sizeof(int),
581                 .mode           = 0644,
582                 .proc_handler   = &proc_dointvec,
583         },
584 #endif
585         {
586                 .ctl_name       = KERN_PIDMAX,
587                 .procname       = "pid_max",
588                 .data           = &pid_max,
589                 .maxlen         = sizeof (int),
590                 .mode           = 0644,
591                 .proc_handler   = &proc_dointvec_minmax,
592                 .strategy       = sysctl_intvec,
593                 .extra1         = &pid_max_min,
594                 .extra2         = &pid_max_max,
595         },
596         {
597                 .ctl_name       = KERN_PANIC_ON_OOPS,
598                 .procname       = "panic_on_oops",
599                 .data           = &panic_on_oops,
600                 .maxlen         = sizeof(int),
601                 .mode           = 0644,
602                 .proc_handler   = &proc_dointvec,
603         },
604         {
605                 .ctl_name       = KERN_PRINTK_RATELIMIT,
606                 .procname       = "printk_ratelimit",
607                 .data           = &printk_ratelimit_jiffies,
608                 .maxlen         = sizeof(int),
609                 .mode           = 0644,
610                 .proc_handler   = &proc_dointvec_jiffies,
611                 .strategy       = &sysctl_jiffies,
612         },
613         {
614                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
615                 .procname       = "printk_ratelimit_burst",
616                 .data           = &printk_ratelimit_burst,
617                 .maxlen         = sizeof(int),
618                 .mode           = 0644,
619                 .proc_handler   = &proc_dointvec,
620         },
621         {
622                 .ctl_name       = KERN_NGROUPS_MAX,
623                 .procname       = "ngroups_max",
624                 .data           = &ngroups_max,
625                 .maxlen         = sizeof (int),
626                 .mode           = 0444,
627                 .proc_handler   = &proc_dointvec,
628         },
629 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
630         {
631                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
632                 .procname       = "unknown_nmi_panic",
633                 .data           = &unknown_nmi_panic,
634                 .maxlen         = sizeof (int),
635                 .mode           = 0644,
636                 .proc_handler   = &proc_dointvec,
637         },
638         {
639                 .ctl_name       = KERN_NMI_WATCHDOG,
640                 .procname       = "nmi_watchdog",
641                 .data           = &nmi_watchdog_enabled,
642                 .maxlen         = sizeof (int),
643                 .mode           = 0644,
644                 .proc_handler   = &proc_nmi_enabled,
645         },
646 #endif
647 #if defined(CONFIG_X86)
648         {
649                 .ctl_name       = KERN_PANIC_ON_NMI,
650                 .procname       = "panic_on_unrecovered_nmi",
651                 .data           = &panic_on_unrecovered_nmi,
652                 .maxlen         = sizeof(int),
653                 .mode           = 0644,
654                 .proc_handler   = &proc_dointvec,
655         },
656         {
657                 .ctl_name       = KERN_BOOTLOADER_TYPE,
658                 .procname       = "bootloader_type",
659                 .data           = &bootloader_type,
660                 .maxlen         = sizeof (int),
661                 .mode           = 0444,
662                 .proc_handler   = &proc_dointvec,
663         },
664         {
665                 .ctl_name       = CTL_UNNUMBERED,
666                 .procname       = "kstack_depth_to_print",
667                 .data           = &kstack_depth_to_print,
668                 .maxlen         = sizeof(int),
669                 .mode           = 0644,
670                 .proc_handler   = &proc_dointvec,
671         },
672 #endif
673 #if defined(CONFIG_MMU)
674         {
675                 .ctl_name       = KERN_RANDOMIZE,
676                 .procname       = "randomize_va_space",
677                 .data           = &randomize_va_space,
678                 .maxlen         = sizeof(int),
679                 .mode           = 0644,
680                 .proc_handler   = &proc_dointvec,
681         },
682 #endif
683 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
684         {
685                 .ctl_name       = KERN_SPIN_RETRY,
686                 .procname       = "spin_retry",
687                 .data           = &spin_retry,
688                 .maxlen         = sizeof (int),
689                 .mode           = 0644,
690                 .proc_handler   = &proc_dointvec,
691         },
692 #endif
693 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
694         {
695                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
696                 .procname       = "acpi_video_flags",
697                 .data           = &acpi_realmode_flags,
698                 .maxlen         = sizeof (unsigned long),
699                 .mode           = 0644,
700                 .proc_handler   = &proc_doulongvec_minmax,
701         },
702 #endif
703 #ifdef CONFIG_IA64
704         {
705                 .ctl_name       = KERN_IA64_UNALIGNED,
706                 .procname       = "ignore-unaligned-usertrap",
707                 .data           = &no_unaligned_warning,
708                 .maxlen         = sizeof (int),
709                 .mode           = 0644,
710                 .proc_handler   = &proc_dointvec,
711         },
712 #endif
713 #ifdef CONFIG_COMPAT
714         {
715                 .ctl_name       = KERN_COMPAT_LOG,
716                 .procname       = "compat-log",
717                 .data           = &compat_log,
718                 .maxlen         = sizeof (int),
719                 .mode           = 0644,
720                 .proc_handler   = &proc_dointvec,
721         },
722 #endif
723 #ifdef CONFIG_RT_MUTEXES
724         {
725                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
726                 .procname       = "max_lock_depth",
727                 .data           = &max_lock_depth,
728                 .maxlen         = sizeof(int),
729                 .mode           = 0644,
730                 .proc_handler   = &proc_dointvec,
731         },
732 #endif
733 #ifdef CONFIG_PROC_FS
734         {
735                 .ctl_name       = CTL_UNNUMBERED,
736                 .procname       = "maps_protect",
737                 .data           = &maps_protect,
738                 .maxlen         = sizeof(int),
739                 .mode           = 0644,
740                 .proc_handler   = &proc_dointvec,
741         },
742 #endif
743         {
744                 .ctl_name       = CTL_UNNUMBERED,
745                 .procname       = "poweroff_cmd",
746                 .data           = &poweroff_cmd,
747                 .maxlen         = POWEROFF_CMD_PATH_LEN,
748                 .mode           = 0644,
749                 .proc_handler   = &proc_dostring,
750                 .strategy       = &sysctl_string,
751         },
752 /*
753  * NOTE: do not add new entries to this table unless you have read
754  * Documentation/sysctl/ctl_unnumbered.txt
755  */
756         { .ctl_name = 0 }
757 };
758
759 /* Constants for minimum and maximum testing in vm_table.
760    We use these as one-element integer vectors. */
761 static int zero;
762 static int two = 2;
763 static int one_hundred = 100;
764
765
766 static ctl_table vm_table[] = {
767         {
768                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
769                 .procname       = "overcommit_memory",
770                 .data           = &sysctl_overcommit_memory,
771                 .maxlen         = sizeof(sysctl_overcommit_memory),
772                 .mode           = 0644,
773                 .proc_handler   = &proc_dointvec,
774         },
775         {
776                 .ctl_name       = VM_PANIC_ON_OOM,
777                 .procname       = "panic_on_oom",
778                 .data           = &sysctl_panic_on_oom,
779                 .maxlen         = sizeof(sysctl_panic_on_oom),
780                 .mode           = 0644,
781                 .proc_handler   = &proc_dointvec,
782         },
783         {
784                 .ctl_name       = VM_OVERCOMMIT_RATIO,
785                 .procname       = "overcommit_ratio",
786                 .data           = &sysctl_overcommit_ratio,
787                 .maxlen         = sizeof(sysctl_overcommit_ratio),
788                 .mode           = 0644,
789                 .proc_handler   = &proc_dointvec,
790         },
791         {
792                 .ctl_name       = VM_PAGE_CLUSTER,
793                 .procname       = "page-cluster", 
794                 .data           = &page_cluster,
795                 .maxlen         = sizeof(int),
796                 .mode           = 0644,
797                 .proc_handler   = &proc_dointvec,
798         },
799         {
800                 .ctl_name       = VM_DIRTY_BACKGROUND,
801                 .procname       = "dirty_background_ratio",
802                 .data           = &dirty_background_ratio,
803                 .maxlen         = sizeof(dirty_background_ratio),
804                 .mode           = 0644,
805                 .proc_handler   = &proc_dointvec_minmax,
806                 .strategy       = &sysctl_intvec,
807                 .extra1         = &zero,
808                 .extra2         = &one_hundred,
809         },
810         {
811                 .ctl_name       = VM_DIRTY_RATIO,
812                 .procname       = "dirty_ratio",
813                 .data           = &vm_dirty_ratio,
814                 .maxlen         = sizeof(vm_dirty_ratio),
815                 .mode           = 0644,
816                 .proc_handler   = &proc_dointvec_minmax,
817                 .strategy       = &sysctl_intvec,
818                 .extra1         = &zero,
819                 .extra2         = &one_hundred,
820         },
821         {
822                 .ctl_name       = VM_DIRTY_WB_CS,
823                 .procname       = "dirty_writeback_centisecs",
824                 .data           = &dirty_writeback_interval,
825                 .maxlen         = sizeof(dirty_writeback_interval),
826                 .mode           = 0644,
827                 .proc_handler   = &dirty_writeback_centisecs_handler,
828         },
829         {
830                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
831                 .procname       = "dirty_expire_centisecs",
832                 .data           = &dirty_expire_interval,
833                 .maxlen         = sizeof(dirty_expire_interval),
834                 .mode           = 0644,
835                 .proc_handler   = &proc_dointvec_userhz_jiffies,
836         },
837         {
838                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
839                 .procname       = "nr_pdflush_threads",
840                 .data           = &nr_pdflush_threads,
841                 .maxlen         = sizeof nr_pdflush_threads,
842                 .mode           = 0444 /* read-only*/,
843                 .proc_handler   = &proc_dointvec,
844         },
845         {
846                 .ctl_name       = VM_SWAPPINESS,
847                 .procname       = "swappiness",
848                 .data           = &vm_swappiness,
849                 .maxlen         = sizeof(vm_swappiness),
850                 .mode           = 0644,
851                 .proc_handler   = &proc_dointvec_minmax,
852                 .strategy       = &sysctl_intvec,
853                 .extra1         = &zero,
854                 .extra2         = &one_hundred,
855         },
856 #ifdef CONFIG_HUGETLB_PAGE
857          {
858                 .ctl_name       = VM_HUGETLB_PAGES,
859                 .procname       = "nr_hugepages",
860                 .data           = &max_huge_pages,
861                 .maxlen         = sizeof(unsigned long),
862                 .mode           = 0644,
863                 .proc_handler   = &hugetlb_sysctl_handler,
864                 .extra1         = (void *)&hugetlb_zero,
865                 .extra2         = (void *)&hugetlb_infinity,
866          },
867          {
868                 .ctl_name       = VM_HUGETLB_GROUP,
869                 .procname       = "hugetlb_shm_group",
870                 .data           = &sysctl_hugetlb_shm_group,
871                 .maxlen         = sizeof(gid_t),
872                 .mode           = 0644,
873                 .proc_handler   = &proc_dointvec,
874          },
875          {
876                 .ctl_name       = CTL_UNNUMBERED,
877                 .procname       = "hugepages_treat_as_movable",
878                 .data           = &hugepages_treat_as_movable,
879                 .maxlen         = sizeof(int),
880                 .mode           = 0644,
881                 .proc_handler   = &hugetlb_treat_movable_handler,
882         },
883         {
884                 .ctl_name       = CTL_UNNUMBERED,
885                 .procname       = "hugetlb_dynamic_pool",
886                 .data           = &hugetlb_dynamic_pool,
887                 .maxlen         = sizeof(hugetlb_dynamic_pool),
888                 .mode           = 0644,
889                 .proc_handler   = &proc_dointvec,
890         },
891 #endif
892         {
893                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
894                 .procname       = "lowmem_reserve_ratio",
895                 .data           = &sysctl_lowmem_reserve_ratio,
896                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
897                 .mode           = 0644,
898                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
899                 .strategy       = &sysctl_intvec,
900         },
901         {
902                 .ctl_name       = VM_DROP_PAGECACHE,
903                 .procname       = "drop_caches",
904                 .data           = &sysctl_drop_caches,
905                 .maxlen         = sizeof(int),
906                 .mode           = 0644,
907                 .proc_handler   = drop_caches_sysctl_handler,
908                 .strategy       = &sysctl_intvec,
909         },
910         {
911                 .ctl_name       = VM_MIN_FREE_KBYTES,
912                 .procname       = "min_free_kbytes",
913                 .data           = &min_free_kbytes,
914                 .maxlen         = sizeof(min_free_kbytes),
915                 .mode           = 0644,
916                 .proc_handler   = &min_free_kbytes_sysctl_handler,
917                 .strategy       = &sysctl_intvec,
918                 .extra1         = &zero,
919         },
920         {
921                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
922                 .procname       = "percpu_pagelist_fraction",
923                 .data           = &percpu_pagelist_fraction,
924                 .maxlen         = sizeof(percpu_pagelist_fraction),
925                 .mode           = 0644,
926                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
927                 .strategy       = &sysctl_intvec,
928                 .extra1         = &min_percpu_pagelist_fract,
929         },
930 #ifdef CONFIG_MMU
931         {
932                 .ctl_name       = VM_MAX_MAP_COUNT,
933                 .procname       = "max_map_count",
934                 .data           = &sysctl_max_map_count,
935                 .maxlen         = sizeof(sysctl_max_map_count),
936                 .mode           = 0644,
937                 .proc_handler   = &proc_dointvec
938         },
939 #endif
940         {
941                 .ctl_name       = VM_LAPTOP_MODE,
942                 .procname       = "laptop_mode",
943                 .data           = &laptop_mode,
944                 .maxlen         = sizeof(laptop_mode),
945                 .mode           = 0644,
946                 .proc_handler   = &proc_dointvec_jiffies,
947                 .strategy       = &sysctl_jiffies,
948         },
949         {
950                 .ctl_name       = VM_BLOCK_DUMP,
951                 .procname       = "block_dump",
952                 .data           = &block_dump,
953                 .maxlen         = sizeof(block_dump),
954                 .mode           = 0644,
955                 .proc_handler   = &proc_dointvec,
956                 .strategy       = &sysctl_intvec,
957                 .extra1         = &zero,
958         },
959         {
960                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
961                 .procname       = "vfs_cache_pressure",
962                 .data           = &sysctl_vfs_cache_pressure,
963                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
964                 .mode           = 0644,
965                 .proc_handler   = &proc_dointvec,
966                 .strategy       = &sysctl_intvec,
967                 .extra1         = &zero,
968         },
969 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
970         {
971                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
972                 .procname       = "legacy_va_layout",
973                 .data           = &sysctl_legacy_va_layout,
974                 .maxlen         = sizeof(sysctl_legacy_va_layout),
975                 .mode           = 0644,
976                 .proc_handler   = &proc_dointvec,
977                 .strategy       = &sysctl_intvec,
978                 .extra1         = &zero,
979         },
980 #endif
981 #ifdef CONFIG_NUMA
982         {
983                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
984                 .procname       = "zone_reclaim_mode",
985                 .data           = &zone_reclaim_mode,
986                 .maxlen         = sizeof(zone_reclaim_mode),
987                 .mode           = 0644,
988                 .proc_handler   = &proc_dointvec,
989                 .strategy       = &sysctl_intvec,
990                 .extra1         = &zero,
991         },
992         {
993                 .ctl_name       = VM_MIN_UNMAPPED,
994                 .procname       = "min_unmapped_ratio",
995                 .data           = &sysctl_min_unmapped_ratio,
996                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
997                 .mode           = 0644,
998                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
999                 .strategy       = &sysctl_intvec,
1000                 .extra1         = &zero,
1001                 .extra2         = &one_hundred,
1002         },
1003         {
1004                 .ctl_name       = VM_MIN_SLAB,
1005                 .procname       = "min_slab_ratio",
1006                 .data           = &sysctl_min_slab_ratio,
1007                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1008                 .mode           = 0644,
1009                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1010                 .strategy       = &sysctl_intvec,
1011                 .extra1         = &zero,
1012                 .extra2         = &one_hundred,
1013         },
1014 #endif
1015 #ifdef CONFIG_SMP
1016         {
1017                 .ctl_name       = CTL_UNNUMBERED,
1018                 .procname       = "stat_interval",
1019                 .data           = &sysctl_stat_interval,
1020                 .maxlen         = sizeof(sysctl_stat_interval),
1021                 .mode           = 0644,
1022                 .proc_handler   = &proc_dointvec_jiffies,
1023                 .strategy       = &sysctl_jiffies,
1024         },
1025 #endif
1026 #ifdef CONFIG_SECURITY
1027         {
1028                 .ctl_name       = CTL_UNNUMBERED,
1029                 .procname       = "mmap_min_addr",
1030                 .data           = &mmap_min_addr,
1031                 .maxlen         = sizeof(unsigned long),
1032                 .mode           = 0644,
1033                 .proc_handler   = &proc_doulongvec_minmax,
1034         },
1035 #endif
1036 #ifdef CONFIG_NUMA
1037         {
1038                 .ctl_name       = CTL_UNNUMBERED,
1039                 .procname       = "numa_zonelist_order",
1040                 .data           = &numa_zonelist_order,
1041                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1042                 .mode           = 0644,
1043                 .proc_handler   = &numa_zonelist_order_handler,
1044                 .strategy       = &sysctl_string,
1045         },
1046 #endif
1047 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1048    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1049         {
1050                 .ctl_name       = VM_VDSO_ENABLED,
1051                 .procname       = "vdso_enabled",
1052                 .data           = &vdso_enabled,
1053                 .maxlen         = sizeof(vdso_enabled),
1054                 .mode           = 0644,
1055                 .proc_handler   = &proc_dointvec,
1056                 .strategy       = &sysctl_intvec,
1057                 .extra1         = &zero,
1058         },
1059 #endif
1060 /*
1061  * NOTE: do not add new entries to this table unless you have read
1062  * Documentation/sysctl/ctl_unnumbered.txt
1063  */
1064         { .ctl_name = 0 }
1065 };
1066
1067 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1068 static ctl_table binfmt_misc_table[] = {
1069         { .ctl_name = 0 }
1070 };
1071 #endif
1072
1073 static ctl_table fs_table[] = {
1074         {
1075                 .ctl_name       = FS_NRINODE,
1076                 .procname       = "inode-nr",
1077                 .data           = &inodes_stat,
1078                 .maxlen         = 2*sizeof(int),
1079                 .mode           = 0444,
1080                 .proc_handler   = &proc_dointvec,
1081         },
1082         {
1083                 .ctl_name       = FS_STATINODE,
1084                 .procname       = "inode-state",
1085                 .data           = &inodes_stat,
1086                 .maxlen         = 7*sizeof(int),
1087                 .mode           = 0444,
1088                 .proc_handler   = &proc_dointvec,
1089         },
1090         {
1091                 .ctl_name       = FS_NRFILE,
1092                 .procname       = "file-nr",
1093                 .data           = &files_stat,
1094                 .maxlen         = 3*sizeof(int),
1095                 .mode           = 0444,
1096                 .proc_handler   = &proc_nr_files,
1097         },
1098         {
1099                 .ctl_name       = FS_MAXFILE,
1100                 .procname       = "file-max",
1101                 .data           = &files_stat.max_files,
1102                 .maxlen         = sizeof(int),
1103                 .mode           = 0644,
1104                 .proc_handler   = &proc_dointvec,
1105         },
1106         {
1107                 .ctl_name       = FS_DENTRY,
1108                 .procname       = "dentry-state",
1109                 .data           = &dentry_stat,
1110                 .maxlen         = 6*sizeof(int),
1111                 .mode           = 0444,
1112                 .proc_handler   = &proc_dointvec,
1113         },
1114         {
1115                 .ctl_name       = FS_OVERFLOWUID,
1116                 .procname       = "overflowuid",
1117                 .data           = &fs_overflowuid,
1118                 .maxlen         = sizeof(int),
1119                 .mode           = 0644,
1120                 .proc_handler   = &proc_dointvec_minmax,
1121                 .strategy       = &sysctl_intvec,
1122                 .extra1         = &minolduid,
1123                 .extra2         = &maxolduid,
1124         },
1125         {
1126                 .ctl_name       = FS_OVERFLOWGID,
1127                 .procname       = "overflowgid",
1128                 .data           = &fs_overflowgid,
1129                 .maxlen         = sizeof(int),
1130                 .mode           = 0644,
1131                 .proc_handler   = &proc_dointvec_minmax,
1132                 .strategy       = &sysctl_intvec,
1133                 .extra1         = &minolduid,
1134                 .extra2         = &maxolduid,
1135         },
1136         {
1137                 .ctl_name       = FS_LEASES,
1138                 .procname       = "leases-enable",
1139                 .data           = &leases_enable,
1140                 .maxlen         = sizeof(int),
1141                 .mode           = 0644,
1142                 .proc_handler   = &proc_dointvec,
1143         },
1144 #ifdef CONFIG_DNOTIFY
1145         {
1146                 .ctl_name       = FS_DIR_NOTIFY,
1147                 .procname       = "dir-notify-enable",
1148                 .data           = &dir_notify_enable,
1149                 .maxlen         = sizeof(int),
1150                 .mode           = 0644,
1151                 .proc_handler   = &proc_dointvec,
1152         },
1153 #endif
1154 #ifdef CONFIG_MMU
1155         {
1156                 .ctl_name       = FS_LEASE_TIME,
1157                 .procname       = "lease-break-time",
1158                 .data           = &lease_break_time,
1159                 .maxlen         = sizeof(int),
1160                 .mode           = 0644,
1161                 .proc_handler   = &proc_dointvec_minmax,
1162                 .strategy       = &sysctl_intvec,
1163                 .extra1         = &zero,
1164                 .extra2         = &two,
1165         },
1166         {
1167                 .ctl_name       = FS_AIO_NR,
1168                 .procname       = "aio-nr",
1169                 .data           = &aio_nr,
1170                 .maxlen         = sizeof(aio_nr),
1171                 .mode           = 0444,
1172                 .proc_handler   = &proc_doulongvec_minmax,
1173         },
1174         {
1175                 .ctl_name       = FS_AIO_MAX_NR,
1176                 .procname       = "aio-max-nr",
1177                 .data           = &aio_max_nr,
1178                 .maxlen         = sizeof(aio_max_nr),
1179                 .mode           = 0644,
1180                 .proc_handler   = &proc_doulongvec_minmax,
1181         },
1182 #ifdef CONFIG_INOTIFY_USER
1183         {
1184                 .ctl_name       = FS_INOTIFY,
1185                 .procname       = "inotify",
1186                 .mode           = 0555,
1187                 .child          = inotify_table,
1188         },
1189 #endif  
1190 #endif
1191         {
1192                 .ctl_name       = KERN_SETUID_DUMPABLE,
1193                 .procname       = "suid_dumpable",
1194                 .data           = &suid_dumpable,
1195                 .maxlen         = sizeof(int),
1196                 .mode           = 0644,
1197                 .proc_handler   = &proc_dointvec,
1198         },
1199 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1200         {
1201                 .ctl_name       = CTL_UNNUMBERED,
1202                 .procname       = "binfmt_misc",
1203                 .mode           = 0555,
1204                 .child          = binfmt_misc_table,
1205         },
1206 #endif
1207 /*
1208  * NOTE: do not add new entries to this table unless you have read
1209  * Documentation/sysctl/ctl_unnumbered.txt
1210  */
1211         { .ctl_name = 0 }
1212 };
1213
1214 static ctl_table debug_table[] = {
1215 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1216         {
1217                 .ctl_name       = CTL_UNNUMBERED,
1218                 .procname       = "exception-trace",
1219                 .data           = &show_unhandled_signals,
1220                 .maxlen         = sizeof(int),
1221                 .mode           = 0644,
1222                 .proc_handler   = proc_dointvec
1223         },
1224 #endif
1225         { .ctl_name = 0 }
1226 };
1227
1228 static ctl_table dev_table[] = {
1229         { .ctl_name = 0 }
1230 };
1231
1232 static DEFINE_SPINLOCK(sysctl_lock);
1233
1234 /* called under sysctl_lock */
1235 static int use_table(struct ctl_table_header *p)
1236 {
1237         if (unlikely(p->unregistering))
1238                 return 0;
1239         p->used++;
1240         return 1;
1241 }
1242
1243 /* called under sysctl_lock */
1244 static void unuse_table(struct ctl_table_header *p)
1245 {
1246         if (!--p->used)
1247                 if (unlikely(p->unregistering))
1248                         complete(p->unregistering);
1249 }
1250
1251 /* called under sysctl_lock, will reacquire if has to wait */
1252 static void start_unregistering(struct ctl_table_header *p)
1253 {
1254         /*
1255          * if p->used is 0, nobody will ever touch that entry again;
1256          * we'll eliminate all paths to it before dropping sysctl_lock
1257          */
1258         if (unlikely(p->used)) {
1259                 struct completion wait;
1260                 init_completion(&wait);
1261                 p->unregistering = &wait;
1262                 spin_unlock(&sysctl_lock);
1263                 wait_for_completion(&wait);
1264                 spin_lock(&sysctl_lock);
1265         }
1266         /*
1267          * do not remove from the list until nobody holds it; walking the
1268          * list in do_sysctl() relies on that.
1269          */
1270         list_del_init(&p->ctl_entry);
1271 }
1272
1273 void sysctl_head_finish(struct ctl_table_header *head)
1274 {
1275         if (!head)
1276                 return;
1277         spin_lock(&sysctl_lock);
1278         unuse_table(head);
1279         spin_unlock(&sysctl_lock);
1280 }
1281
1282 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1283 {
1284         struct ctl_table_header *head;
1285         struct list_head *tmp;
1286         spin_lock(&sysctl_lock);
1287         if (prev) {
1288                 tmp = &prev->ctl_entry;
1289                 unuse_table(prev);
1290                 goto next;
1291         }
1292         tmp = &root_table_header.ctl_entry;
1293         for (;;) {
1294                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1295
1296                 if (!use_table(head))
1297                         goto next;
1298                 spin_unlock(&sysctl_lock);
1299                 return head;
1300         next:
1301                 tmp = tmp->next;
1302                 if (tmp == &root_table_header.ctl_entry)
1303                         break;
1304         }
1305         spin_unlock(&sysctl_lock);
1306         return NULL;
1307 }
1308
1309 #ifdef CONFIG_SYSCTL_SYSCALL
1310 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1311                void __user *newval, size_t newlen)
1312 {
1313         struct ctl_table_header *head;
1314         int error = -ENOTDIR;
1315
1316         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1317                 return -ENOTDIR;
1318         if (oldval) {
1319                 int old_len;
1320                 if (!oldlenp || get_user(old_len, oldlenp))
1321                         return -EFAULT;
1322         }
1323
1324         for (head = sysctl_head_next(NULL); head;
1325                         head = sysctl_head_next(head)) {
1326                 error = parse_table(name, nlen, oldval, oldlenp, 
1327                                         newval, newlen, head->ctl_table);
1328                 if (error != -ENOTDIR) {
1329                         sysctl_head_finish(head);
1330                         break;
1331                 }
1332         }
1333         return error;
1334 }
1335
1336 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1337 {
1338         struct __sysctl_args tmp;
1339         int error;
1340
1341         if (copy_from_user(&tmp, args, sizeof(tmp)))
1342                 return -EFAULT;
1343
1344         lock_kernel();
1345         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1346                           tmp.newval, tmp.newlen);
1347         unlock_kernel();
1348         return error;
1349 }
1350 #endif /* CONFIG_SYSCTL_SYSCALL */
1351
1352 /*
1353  * sysctl_perm does NOT grant the superuser all rights automatically, because
1354  * some sysctl variables are readonly even to root.
1355  */
1356
1357 static int test_perm(int mode, int op)
1358 {
1359         if (!current->euid)
1360                 mode >>= 6;
1361         else if (in_egroup_p(0))
1362                 mode >>= 3;
1363         if ((mode & op & 0007) == op)
1364                 return 0;
1365         return -EACCES;
1366 }
1367
1368 int sysctl_perm(ctl_table *table, int op)
1369 {
1370         int error;
1371         error = security_sysctl(table, op);
1372         if (error)
1373                 return error;
1374         return test_perm(table->mode, op);
1375 }
1376
1377 #ifdef CONFIG_SYSCTL_SYSCALL
1378 static int parse_table(int __user *name, int nlen,
1379                        void __user *oldval, size_t __user *oldlenp,
1380                        void __user *newval, size_t newlen,
1381                        ctl_table *table)
1382 {
1383         int n;
1384 repeat:
1385         if (!nlen)
1386                 return -ENOTDIR;
1387         if (get_user(n, name))
1388                 return -EFAULT;
1389         for ( ; table->ctl_name || table->procname; table++) {
1390                 if (!table->ctl_name)
1391                         continue;
1392                 if (n == table->ctl_name) {
1393                         int error;
1394                         if (table->child) {
1395                                 if (sysctl_perm(table, 001))
1396                                         return -EPERM;
1397                                 name++;
1398                                 nlen--;
1399                                 table = table->child;
1400                                 goto repeat;
1401                         }
1402                         error = do_sysctl_strategy(table, name, nlen,
1403                                                    oldval, oldlenp,
1404                                                    newval, newlen);
1405                         return error;
1406                 }
1407         }
1408         return -ENOTDIR;
1409 }
1410
1411 /* Perform the actual read/write of a sysctl table entry. */
1412 int do_sysctl_strategy (ctl_table *table, 
1413                         int __user *name, int nlen,
1414                         void __user *oldval, size_t __user *oldlenp,
1415                         void __user *newval, size_t newlen)
1416 {
1417         int op = 0, rc;
1418         size_t len;
1419
1420         if (oldval)
1421                 op |= 004;
1422         if (newval) 
1423                 op |= 002;
1424         if (sysctl_perm(table, op))
1425                 return -EPERM;
1426
1427         if (table->strategy) {
1428                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1429                                      newval, newlen);
1430                 if (rc < 0)
1431                         return rc;
1432                 if (rc > 0)
1433                         return 0;
1434         }
1435
1436         /* If there is no strategy routine, or if the strategy returns
1437          * zero, proceed with automatic r/w */
1438         if (table->data && table->maxlen) {
1439                 if (oldval && oldlenp) {
1440                         if (get_user(len, oldlenp))
1441                                 return -EFAULT;
1442                         if (len) {
1443                                 if (len > table->maxlen)
1444                                         len = table->maxlen;
1445                                 if(copy_to_user(oldval, table->data, len))
1446                                         return -EFAULT;
1447                                 if(put_user(len, oldlenp))
1448                                         return -EFAULT;
1449                         }
1450                 }
1451                 if (newval && newlen) {
1452                         len = newlen;
1453                         if (len > table->maxlen)
1454                                 len = table->maxlen;
1455                         if(copy_from_user(table->data, newval, len))
1456                                 return -EFAULT;
1457                 }
1458         }
1459         return 0;
1460 }
1461 #endif /* CONFIG_SYSCTL_SYSCALL */
1462
1463 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1464 {
1465         for (; table->ctl_name || table->procname; table++) {
1466                 table->parent = parent;
1467                 if (table->child)
1468                         sysctl_set_parent(table, table->child);
1469         }
1470 }
1471
1472 static __init int sysctl_init(void)
1473 {
1474         sysctl_set_parent(NULL, root_table);
1475         return 0;
1476 }
1477
1478 core_initcall(sysctl_init);
1479
1480 /**
1481  * register_sysctl_table - register a sysctl hierarchy
1482  * @table: the top-level table structure
1483  *
1484  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1485  * array. An entry with a ctl_name of 0 terminates the table. 
1486  *
1487  * The members of the &ctl_table structure are used as follows:
1488  *
1489  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1490  *            must be unique within that level of sysctl
1491  *
1492  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1493  *            enter a sysctl file
1494  *
1495  * data - a pointer to data for use by proc_handler
1496  *
1497  * maxlen - the maximum size in bytes of the data
1498  *
1499  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1500  *
1501  * child - a pointer to the child sysctl table if this entry is a directory, or
1502  *         %NULL.
1503  *
1504  * proc_handler - the text handler routine (described below)
1505  *
1506  * strategy - the strategy routine (described below)
1507  *
1508  * de - for internal use by the sysctl routines
1509  *
1510  * extra1, extra2 - extra pointers usable by the proc handler routines
1511  *
1512  * Leaf nodes in the sysctl tree will be represented by a single file
1513  * under /proc; non-leaf nodes will be represented by directories.
1514  *
1515  * sysctl(2) can automatically manage read and write requests through
1516  * the sysctl table.  The data and maxlen fields of the ctl_table
1517  * struct enable minimal validation of the values being written to be
1518  * performed, and the mode field allows minimal authentication.
1519  *
1520  * More sophisticated management can be enabled by the provision of a
1521  * strategy routine with the table entry.  This will be called before
1522  * any automatic read or write of the data is performed.
1523  *
1524  * The strategy routine may return
1525  *
1526  * < 0 - Error occurred (error is passed to user process)
1527  *
1528  * 0   - OK - proceed with automatic read or write.
1529  *
1530  * > 0 - OK - read or write has been done by the strategy routine, so
1531  *       return immediately.
1532  *
1533  * There must be a proc_handler routine for any terminal nodes
1534  * mirrored under /proc/sys (non-terminals are handled by a built-in
1535  * directory handler).  Several default handlers are available to
1536  * cover common cases -
1537  *
1538  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1539  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 
1540  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1541  *
1542  * It is the handler's job to read the input buffer from user memory
1543  * and process it. The handler should return 0 on success.
1544  *
1545  * This routine returns %NULL on a failure to register, and a pointer
1546  * to the table header on success.
1547  */
1548 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1549 {
1550         struct ctl_table_header *tmp;
1551         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1552         if (!tmp)
1553                 return NULL;
1554         tmp->ctl_table = table;
1555         INIT_LIST_HEAD(&tmp->ctl_entry);
1556         tmp->used = 0;
1557         tmp->unregistering = NULL;
1558         sysctl_set_parent(NULL, table);
1559         spin_lock(&sysctl_lock);
1560         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1561         spin_unlock(&sysctl_lock);
1562         return tmp;
1563 }
1564
1565 /**
1566  * unregister_sysctl_table - unregister a sysctl table hierarchy
1567  * @header: the header returned from register_sysctl_table
1568  *
1569  * Unregisters the sysctl table and all children. proc entries may not
1570  * actually be removed until they are no longer used by anyone.
1571  */
1572 void unregister_sysctl_table(struct ctl_table_header * header)
1573 {
1574         might_sleep();
1575         spin_lock(&sysctl_lock);
1576         start_unregistering(header);
1577         spin_unlock(&sysctl_lock);
1578         kfree(header);
1579 }
1580
1581 #else /* !CONFIG_SYSCTL */
1582 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1583 {
1584         return NULL;
1585 }
1586
1587 void unregister_sysctl_table(struct ctl_table_header * table)
1588 {
1589 }
1590
1591 #endif /* CONFIG_SYSCTL */
1592
1593 /*
1594  * /proc/sys support
1595  */
1596
1597 #ifdef CONFIG_PROC_SYSCTL
1598
1599 static int _proc_do_string(void* data, int maxlen, int write,
1600                            struct file *filp, void __user *buffer,
1601                            size_t *lenp, loff_t *ppos)
1602 {
1603         size_t len;
1604         char __user *p;
1605         char c;
1606
1607         if (!data || !maxlen || !*lenp) {
1608                 *lenp = 0;
1609                 return 0;
1610         }
1611
1612         if (write) {
1613                 len = 0;
1614                 p = buffer;
1615                 while (len < *lenp) {
1616                         if (get_user(c, p++))
1617                                 return -EFAULT;
1618                         if (c == 0 || c == '\n')
1619                                 break;
1620                         len++;
1621                 }
1622                 if (len >= maxlen)
1623                         len = maxlen-1;
1624                 if(copy_from_user(data, buffer, len))
1625                         return -EFAULT;
1626                 ((char *) data)[len] = 0;
1627                 *ppos += *lenp;
1628         } else {
1629                 len = strlen(data);
1630                 if (len > maxlen)
1631                         len = maxlen;
1632
1633                 if (*ppos > len) {
1634                         *lenp = 0;
1635                         return 0;
1636                 }
1637
1638                 data += *ppos;
1639                 len  -= *ppos;
1640
1641                 if (len > *lenp)
1642                         len = *lenp;
1643                 if (len)
1644                         if(copy_to_user(buffer, data, len))
1645                                 return -EFAULT;
1646                 if (len < *lenp) {
1647                         if(put_user('\n', ((char __user *) buffer) + len))
1648                                 return -EFAULT;
1649                         len++;
1650                 }
1651                 *lenp = len;
1652                 *ppos += len;
1653         }
1654         return 0;
1655 }
1656
1657 /**
1658  * proc_dostring - read a string sysctl
1659  * @table: the sysctl table
1660  * @write: %TRUE if this is a write to the sysctl file
1661  * @filp: the file structure
1662  * @buffer: the user buffer
1663  * @lenp: the size of the user buffer
1664  * @ppos: file position
1665  *
1666  * Reads/writes a string from/to the user buffer. If the kernel
1667  * buffer provided is not large enough to hold the string, the
1668  * string is truncated. The copied string is %NULL-terminated.
1669  * If the string is being read by the user process, it is copied
1670  * and a newline '\n' is added. It is truncated if the buffer is
1671  * not large enough.
1672  *
1673  * Returns 0 on success.
1674  */
1675 int proc_dostring(ctl_table *table, int write, struct file *filp,
1676                   void __user *buffer, size_t *lenp, loff_t *ppos)
1677 {
1678         return _proc_do_string(table->data, table->maxlen, write, filp,
1679                                buffer, lenp, ppos);
1680 }
1681
1682
1683 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1684                                  int *valp,
1685                                  int write, void *data)
1686 {
1687         if (write) {
1688                 *valp = *negp ? -*lvalp : *lvalp;
1689         } else {
1690                 int val = *valp;
1691                 if (val < 0) {
1692                         *negp = -1;
1693                         *lvalp = (unsigned long)-val;
1694                 } else {
1695                         *negp = 0;
1696                         *lvalp = (unsigned long)val;
1697                 }
1698         }
1699         return 0;
1700 }
1701
1702 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1703                   int write, struct file *filp, void __user *buffer,
1704                   size_t *lenp, loff_t *ppos,
1705                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1706                               int write, void *data),
1707                   void *data)
1708 {
1709 #define TMPBUFLEN 21
1710         int *i, vleft, first=1, neg, val;
1711         unsigned long lval;
1712         size_t left, len;
1713         
1714         char buf[TMPBUFLEN], *p;
1715         char __user *s = buffer;
1716         
1717         if (!tbl_data || !table->maxlen || !*lenp ||
1718             (*ppos && !write)) {
1719                 *lenp = 0;
1720                 return 0;
1721         }
1722         
1723         i = (int *) tbl_data;
1724         vleft = table->maxlen / sizeof(*i);
1725         left = *lenp;
1726
1727         if (!conv)
1728                 conv = do_proc_dointvec_conv;
1729
1730         for (; left && vleft--; i++, first=0) {
1731                 if (write) {
1732                         while (left) {
1733                                 char c;
1734                                 if (get_user(c, s))
1735                                         return -EFAULT;
1736                                 if (!isspace(c))
1737                                         break;
1738                                 left--;
1739                                 s++;
1740                         }
1741                         if (!left)
1742                                 break;
1743                         neg = 0;
1744                         len = left;
1745                         if (len > sizeof(buf) - 1)
1746                                 len = sizeof(buf) - 1;
1747                         if (copy_from_user(buf, s, len))
1748                                 return -EFAULT;
1749                         buf[len] = 0;
1750                         p = buf;
1751                         if (*p == '-' && left > 1) {
1752                                 neg = 1;
1753                                 p++;
1754                         }
1755                         if (*p < '0' || *p > '9')
1756                                 break;
1757
1758                         lval = simple_strtoul(p, &p, 0);
1759
1760                         len = p-buf;
1761                         if ((len < left) && *p && !isspace(*p))
1762                                 break;
1763                         if (neg)
1764                                 val = -val;
1765                         s += len;
1766                         left -= len;
1767
1768                         if (conv(&neg, &lval, i, 1, data))
1769                                 break;
1770                 } else {
1771                         p = buf;
1772                         if (!first)
1773                                 *p++ = '\t';
1774         
1775                         if (conv(&neg, &lval, i, 0, data))
1776                                 break;
1777
1778                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1779                         len = strlen(buf);
1780                         if (len > left)
1781                                 len = left;
1782                         if(copy_to_user(s, buf, len))
1783                                 return -EFAULT;
1784                         left -= len;
1785                         s += len;
1786                 }
1787         }
1788
1789         if (!write && !first && left) {
1790                 if(put_user('\n', s))
1791                         return -EFAULT;
1792                 left--, s++;
1793         }
1794         if (write) {
1795                 while (left) {
1796                         char c;
1797                         if (get_user(c, s++))
1798                                 return -EFAULT;
1799                         if (!isspace(c))
1800                                 break;
1801                         left--;
1802                 }
1803         }
1804         if (write && first)
1805                 return -EINVAL;
1806         *lenp -= left;
1807         *ppos += *lenp;
1808         return 0;
1809 #undef TMPBUFLEN
1810 }
1811
1812 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1813                   void __user *buffer, size_t *lenp, loff_t *ppos,
1814                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1815                               int write, void *data),
1816                   void *data)
1817 {
1818         return __do_proc_dointvec(table->data, table, write, filp,
1819                         buffer, lenp, ppos, conv, data);
1820 }
1821
1822 /**
1823  * proc_dointvec - read a vector of integers
1824  * @table: the sysctl table
1825  * @write: %TRUE if this is a write to the sysctl file
1826  * @filp: the file structure
1827  * @buffer: the user buffer
1828  * @lenp: the size of the user buffer
1829  * @ppos: file position
1830  *
1831  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1832  * values from/to the user buffer, treated as an ASCII string. 
1833  *
1834  * Returns 0 on success.
1835  */
1836 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1837                      void __user *buffer, size_t *lenp, loff_t *ppos)
1838 {
1839     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1840                             NULL,NULL);
1841 }
1842
1843 #define OP_SET  0
1844 #define OP_AND  1
1845 #define OP_OR   2
1846
1847 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1848                                       int *valp,
1849                                       int write, void *data)
1850 {
1851         int op = *(int *)data;
1852         if (write) {
1853                 int val = *negp ? -*lvalp : *lvalp;
1854                 switch(op) {
1855                 case OP_SET:    *valp = val; break;
1856                 case OP_AND:    *valp &= val; break;
1857                 case OP_OR:     *valp |= val; break;
1858                 }
1859         } else {
1860                 int val = *valp;
1861                 if (val < 0) {
1862                         *negp = -1;
1863                         *lvalp = (unsigned long)-val;
1864                 } else {
1865                         *negp = 0;
1866                         *lvalp = (unsigned long)val;
1867                 }
1868         }
1869         return 0;
1870 }
1871
1872 /*
1873  *      init may raise the set.
1874  */
1875  
1876 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1877                         void __user *buffer, size_t *lenp, loff_t *ppos)
1878 {
1879         int op;
1880
1881         if (write && !capable(CAP_SYS_MODULE)) {
1882                 return -EPERM;
1883         }
1884
1885         op = is_init(current) ? OP_SET : OP_AND;
1886         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1887                                 do_proc_dointvec_bset_conv,&op);
1888 }
1889
1890 /*
1891  *      Taint values can only be increased
1892  */
1893 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1894                                void __user *buffer, size_t *lenp, loff_t *ppos)
1895 {
1896         int op;
1897
1898         if (write && !capable(CAP_SYS_ADMIN))
1899                 return -EPERM;
1900
1901         op = OP_OR;
1902         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1903                                 do_proc_dointvec_bset_conv,&op);
1904 }
1905
1906 struct do_proc_dointvec_minmax_conv_param {
1907         int *min;
1908         int *max;
1909 };
1910
1911 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, 
1912                                         int *valp, 
1913                                         int write, void *data)
1914 {
1915         struct do_proc_dointvec_minmax_conv_param *param = data;
1916         if (write) {
1917                 int val = *negp ? -*lvalp : *lvalp;
1918                 if ((param->min && *param->min > val) ||
1919                     (param->max && *param->max < val))
1920                         return -EINVAL;
1921                 *valp = val;
1922         } else {
1923                 int val = *valp;
1924                 if (val < 0) {
1925                         *negp = -1;
1926                         *lvalp = (unsigned long)-val;
1927                 } else {
1928                         *negp = 0;
1929                         *lvalp = (unsigned long)val;
1930                 }
1931         }
1932         return 0;
1933 }
1934
1935 /**
1936  * proc_dointvec_minmax - read a vector of integers with min/max values
1937  * @table: the sysctl table
1938  * @write: %TRUE if this is a write to the sysctl file
1939  * @filp: the file structure
1940  * @buffer: the user buffer
1941  * @lenp: the size of the user buffer
1942  * @ppos: file position
1943  *
1944  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1945  * values from/to the user buffer, treated as an ASCII string.
1946  *
1947  * This routine will ensure the values are within the range specified by
1948  * table->extra1 (min) and table->extra2 (max).
1949  *
1950  * Returns 0 on success.
1951  */
1952 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1953                   void __user *buffer, size_t *lenp, loff_t *ppos)
1954 {
1955         struct do_proc_dointvec_minmax_conv_param param = {
1956                 .min = (int *) table->extra1,
1957                 .max = (int *) table->extra2,
1958         };
1959         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1960                                 do_proc_dointvec_minmax_conv, &param);
1961 }
1962
1963 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1964                                      struct file *filp,
1965                                      void __user *buffer,
1966                                      size_t *lenp, loff_t *ppos,
1967                                      unsigned long convmul,
1968                                      unsigned long convdiv)
1969 {
1970 #define TMPBUFLEN 21
1971         unsigned long *i, *min, *max, val;
1972         int vleft, first=1, neg;
1973         size_t len, left;
1974         char buf[TMPBUFLEN], *p;
1975         char __user *s = buffer;
1976         
1977         if (!data || !table->maxlen || !*lenp ||
1978             (*ppos && !write)) {
1979                 *lenp = 0;
1980                 return 0;
1981         }
1982         
1983         i = (unsigned long *) data;
1984         min = (unsigned long *) table->extra1;
1985         max = (unsigned long *) table->extra2;
1986         vleft = table->maxlen / sizeof(unsigned long);
1987         left = *lenp;
1988         
1989         for (; left && vleft--; i++, min++, max++, first=0) {
1990                 if (write) {
1991                         while (left) {
1992                                 char c;
1993                                 if (get_user(c, s))
1994                                         return -EFAULT;
1995                                 if (!isspace(c))
1996                                         break;
1997                                 left--;
1998                                 s++;
1999                         }
2000                         if (!left)
2001                                 break;
2002                         neg = 0;
2003                         len = left;
2004                         if (len > TMPBUFLEN-1)
2005                                 len = TMPBUFLEN-1;
2006                         if (copy_from_user(buf, s, len))
2007                                 return -EFAULT;
2008                         buf[len] = 0;
2009                         p = buf;
2010                         if (*p == '-' && left > 1) {
2011                                 neg = 1;
2012                                 p++;
2013                         }
2014                         if (*p < '0' || *p > '9')
2015                                 break;
2016                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2017                         len = p-buf;
2018                         if ((len < left) && *p && !isspace(*p))
2019                                 break;
2020                         if (neg)
2021                                 val = -val;
2022                         s += len;
2023                         left -= len;
2024
2025                         if(neg)
2026                                 continue;
2027                         if ((min && val < *min) || (max && val > *max))
2028                                 continue;
2029                         *i = val;
2030                 } else {
2031                         p = buf;
2032                         if (!first)
2033                                 *p++ = '\t';
2034                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2035                         len = strlen(buf);
2036                         if (len > left)
2037                                 len = left;
2038                         if(copy_to_user(s, buf, len))
2039                                 return -EFAULT;
2040                         left -= len;
2041                         s += len;
2042                 }
2043         }
2044
2045         if (!write && !first && left) {
2046                 if(put_user('\n', s))
2047                         return -EFAULT;
2048                 left--, s++;
2049         }
2050         if (write) {
2051                 while (left) {
2052                         char c;
2053                         if (get_user(c, s++))
2054                                 return -EFAULT;
2055                         if (!isspace(c))
2056                                 break;
2057                         left--;
2058                 }
2059         }
2060         if (write && first)
2061                 return -EINVAL;
2062         *lenp -= left;
2063         *ppos += *lenp;
2064         return 0;
2065 #undef TMPBUFLEN
2066 }
2067
2068 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2069                                      struct file *filp,
2070                                      void __user *buffer,
2071                                      size_t *lenp, loff_t *ppos,
2072                                      unsigned long convmul,
2073                                      unsigned long convdiv)
2074 {
2075         return __do_proc_doulongvec_minmax(table->data, table, write,
2076                         filp, buffer, lenp, ppos, convmul, convdiv);
2077 }
2078
2079 /**
2080  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2081  * @table: the sysctl table
2082  * @write: %TRUE if this is a write to the sysctl file
2083  * @filp: the file structure
2084  * @buffer: the user buffer
2085  * @lenp: the size of the user buffer
2086  * @ppos: file position
2087  *
2088  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2089  * values from/to the user buffer, treated as an ASCII string.
2090  *
2091  * This routine will ensure the values are within the range specified by
2092  * table->extra1 (min) and table->extra2 (max).
2093  *
2094  * Returns 0 on success.
2095  */
2096 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2097                            void __user *buffer, size_t *lenp, loff_t *ppos)
2098 {
2099     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2100 }
2101
2102 /**
2103  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2104  * @table: the sysctl table
2105  * @write: %TRUE if this is a write to the sysctl file
2106  * @filp: the file structure
2107  * @buffer: the user buffer
2108  * @lenp: the size of the user buffer
2109  * @ppos: file position
2110  *
2111  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2112  * values from/to the user buffer, treated as an ASCII string. The values
2113  * are treated as milliseconds, and converted to jiffies when they are stored.
2114  *
2115  * This routine will ensure the values are within the range specified by
2116  * table->extra1 (min) and table->extra2 (max).
2117  *
2118  * Returns 0 on success.
2119  */
2120 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2121                                       struct file *filp,
2122                                       void __user *buffer,
2123                                       size_t *lenp, loff_t *ppos)
2124 {
2125     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2126                                      lenp, ppos, HZ, 1000l);
2127 }
2128
2129
2130 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2131                                          int *valp,
2132                                          int write, void *data)
2133 {
2134         if (write) {
2135                 if (*lvalp > LONG_MAX / HZ)
2136                         return 1;
2137                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2138         } else {
2139                 int val = *valp;
2140                 unsigned long lval;
2141                 if (val < 0) {
2142                         *negp = -1;
2143                         lval = (unsigned long)-val;
2144                 } else {
2145                         *negp = 0;
2146                         lval = (unsigned long)val;
2147                 }
2148                 *lvalp = lval / HZ;
2149         }
2150         return 0;
2151 }
2152
2153 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2154                                                 int *valp,
2155                                                 int write, void *data)
2156 {
2157         if (write) {
2158                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2159                         return 1;
2160                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2161         } else {
2162                 int val = *valp;
2163                 unsigned long lval;
2164                 if (val < 0) {
2165                         *negp = -1;
2166                         lval = (unsigned long)-val;
2167                 } else {
2168                         *negp = 0;
2169                         lval = (unsigned long)val;
2170                 }
2171                 *lvalp = jiffies_to_clock_t(lval);
2172         }
2173         return 0;
2174 }
2175
2176 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2177                                             int *valp,
2178                                             int write, void *data)
2179 {
2180         if (write) {
2181                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2182         } else {
2183                 int val = *valp;
2184                 unsigned long lval;
2185                 if (val < 0) {
2186                         *negp = -1;
2187                         lval = (unsigned long)-val;
2188                 } else {
2189                         *negp = 0;
2190                         lval = (unsigned long)val;
2191                 }
2192                 *lvalp = jiffies_to_msecs(lval);
2193         }
2194         return 0;
2195 }
2196
2197 /**
2198  * proc_dointvec_jiffies - read a vector of integers as seconds
2199  * @table: the sysctl table
2200  * @write: %TRUE if this is a write to the sysctl file
2201  * @filp: the file structure
2202  * @buffer: the user buffer
2203  * @lenp: the size of the user buffer
2204  * @ppos: file position
2205  *
2206  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2207  * values from/to the user buffer, treated as an ASCII string. 
2208  * The values read are assumed to be in seconds, and are converted into
2209  * jiffies.
2210  *
2211  * Returns 0 on success.
2212  */
2213 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2214                           void __user *buffer, size_t *lenp, loff_t *ppos)
2215 {
2216     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2217                             do_proc_dointvec_jiffies_conv,NULL);
2218 }
2219
2220 /**
2221  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2222  * @table: the sysctl table
2223  * @write: %TRUE if this is a write to the sysctl file
2224  * @filp: the file structure
2225  * @buffer: the user buffer
2226  * @lenp: the size of the user buffer
2227  * @ppos: pointer to the file position
2228  *
2229  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2230  * values from/to the user buffer, treated as an ASCII string. 
2231  * The values read are assumed to be in 1/USER_HZ seconds, and 
2232  * are converted into jiffies.
2233  *
2234  * Returns 0 on success.
2235  */
2236 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2237                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2238 {
2239     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2240                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2241 }
2242
2243 /**
2244  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2245  * @table: the sysctl table
2246  * @write: %TRUE if this is a write to the sysctl file
2247  * @filp: the file structure
2248  * @buffer: the user buffer
2249  * @lenp: the size of the user buffer
2250  * @ppos: file position
2251  * @ppos: the current position in the file
2252  *
2253  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2254  * values from/to the user buffer, treated as an ASCII string. 
2255  * The values read are assumed to be in 1/1000 seconds, and 
2256  * are converted into jiffies.
2257  *
2258  * Returns 0 on success.
2259  */
2260 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2261                              void __user *buffer, size_t *lenp, loff_t *ppos)
2262 {
2263         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2264                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2265 }
2266
2267 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2268                            void __user *buffer, size_t *lenp, loff_t *ppos)
2269 {
2270         struct pid *new_pid;
2271         pid_t tmp;
2272         int r;
2273
2274         tmp = pid_nr(cad_pid);
2275
2276         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2277                                lenp, ppos, NULL, NULL);
2278         if (r || !write)
2279                 return r;
2280
2281         new_pid = find_get_pid(tmp);
2282         if (!new_pid)
2283                 return -ESRCH;
2284
2285         put_pid(xchg(&cad_pid, new_pid));
2286         return 0;
2287 }
2288
2289 #else /* CONFIG_PROC_FS */
2290
2291 int proc_dostring(ctl_table *table, int write, struct file *filp,
2292                   void __user *buffer, size_t *lenp, loff_t *ppos)
2293 {
2294         return -ENOSYS;
2295 }
2296
2297 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2298                   void __user *buffer, size_t *lenp, loff_t *ppos)
2299 {
2300         return -ENOSYS;
2301 }
2302
2303 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2304                         void __user *buffer, size_t *lenp, loff_t *ppos)
2305 {
2306         return -ENOSYS;
2307 }
2308
2309 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2310                     void __user *buffer, size_t *lenp, loff_t *ppos)
2311 {
2312         return -ENOSYS;
2313 }
2314
2315 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2316                     void __user *buffer, size_t *lenp, loff_t *ppos)
2317 {
2318         return -ENOSYS;
2319 }
2320
2321 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2322                     void __user *buffer, size_t *lenp, loff_t *ppos)
2323 {
2324         return -ENOSYS;
2325 }
2326
2327 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2328                              void __user *buffer, size_t *lenp, loff_t *ppos)
2329 {
2330         return -ENOSYS;
2331 }
2332
2333 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2334                     void __user *buffer, size_t *lenp, loff_t *ppos)
2335 {
2336         return -ENOSYS;
2337 }
2338
2339 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2340                                       struct file *filp,
2341                                       void __user *buffer,
2342                                       size_t *lenp, loff_t *ppos)
2343 {
2344     return -ENOSYS;
2345 }
2346
2347
2348 #endif /* CONFIG_PROC_FS */
2349
2350
2351 #ifdef CONFIG_SYSCTL_SYSCALL
2352 /*
2353  * General sysctl support routines 
2354  */
2355
2356 /* The generic string strategy routine: */
2357 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2358                   void __user *oldval, size_t __user *oldlenp,
2359                   void __user *newval, size_t newlen)
2360 {
2361         if (!table->data || !table->maxlen) 
2362                 return -ENOTDIR;
2363         
2364         if (oldval && oldlenp) {
2365                 size_t bufsize;
2366                 if (get_user(bufsize, oldlenp))
2367                         return -EFAULT;
2368                 if (bufsize) {
2369                         size_t len = strlen(table->data), copied;
2370
2371                         /* This shouldn't trigger for a well-formed sysctl */
2372                         if (len > table->maxlen)
2373                                 len = table->maxlen;
2374
2375                         /* Copy up to a max of bufsize-1 bytes of the string */
2376                         copied = (len >= bufsize) ? bufsize - 1 : len;
2377
2378                         if (copy_to_user(oldval, table->data, copied) ||
2379                             put_user(0, (char __user *)(oldval + copied)))
2380                                 return -EFAULT;
2381                         if (put_user(len, oldlenp))
2382                                 return -EFAULT;
2383                 }
2384         }
2385         if (newval && newlen) {
2386                 size_t len = newlen;
2387                 if (len > table->maxlen)
2388                         len = table->maxlen;
2389                 if(copy_from_user(table->data, newval, len))
2390                         return -EFAULT;
2391                 if (len == table->maxlen)
2392                         len--;
2393                 ((char *) table->data)[len] = 0;
2394         }
2395         return 1;
2396 }
2397
2398 /*
2399  * This function makes sure that all of the integers in the vector
2400  * are between the minimum and maximum values given in the arrays
2401  * table->extra1 and table->extra2, respectively.
2402  */
2403 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2404                 void __user *oldval, size_t __user *oldlenp,
2405                 void __user *newval, size_t newlen)
2406 {
2407
2408         if (newval && newlen) {
2409                 int __user *vec = (int __user *) newval;
2410                 int *min = (int *) table->extra1;
2411                 int *max = (int *) table->extra2;
2412                 size_t length;
2413                 int i;
2414
2415                 if (newlen % sizeof(int) != 0)
2416                         return -EINVAL;
2417
2418                 if (!table->extra1 && !table->extra2)
2419                         return 0;
2420
2421                 if (newlen > table->maxlen)
2422                         newlen = table->maxlen;
2423                 length = newlen / sizeof(int);
2424
2425                 for (i = 0; i < length; i++) {
2426                         int value;
2427                         if (get_user(value, vec + i))
2428                                 return -EFAULT;
2429                         if (min && value < min[i])
2430                                 return -EINVAL;
2431                         if (max && value > max[i])
2432                                 return -EINVAL;
2433                 }
2434         }
2435         return 0;
2436 }
2437
2438 /* Strategy function to convert jiffies to seconds */ 
2439 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2440                 void __user *oldval, size_t __user *oldlenp,
2441                 void __user *newval, size_t newlen)
2442 {
2443         if (oldval && oldlenp) {
2444                 size_t olen;
2445
2446                 if (get_user(olen, oldlenp))
2447                         return -EFAULT;
2448                 if (olen) {
2449                         int val;
2450
2451                         if (olen < sizeof(int))
2452                                 return -EINVAL;
2453
2454                         val = *(int *)(table->data) / HZ;
2455                         if (put_user(val, (int __user *)oldval))
2456                                 return -EFAULT;
2457                         if (put_user(sizeof(int), oldlenp))
2458                                 return -EFAULT;
2459                 }
2460         }
2461         if (newval && newlen) { 
2462                 int new;
2463                 if (newlen != sizeof(int))
2464                         return -EINVAL; 
2465                 if (get_user(new, (int __user *)newval))
2466                         return -EFAULT;
2467                 *(int *)(table->data) = new*HZ; 
2468         }
2469         return 1;
2470 }
2471
2472 /* Strategy function to convert jiffies to seconds */ 
2473 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2474                 void __user *oldval, size_t __user *oldlenp,
2475                 void __user *newval, size_t newlen)
2476 {
2477         if (oldval && oldlenp) {
2478                 size_t olen;
2479
2480                 if (get_user(olen, oldlenp))
2481                         return -EFAULT;
2482                 if (olen) {
2483                         int val;
2484
2485                         if (olen < sizeof(int))
2486                                 return -EINVAL;
2487
2488                         val = jiffies_to_msecs(*(int *)(table->data));
2489                         if (put_user(val, (int __user *)oldval))
2490                                 return -EFAULT;
2491                         if (put_user(sizeof(int), oldlenp))
2492                                 return -EFAULT;
2493                 }
2494         }
2495         if (newval && newlen) { 
2496                 int new;
2497                 if (newlen != sizeof(int))
2498                         return -EINVAL; 
2499                 if (get_user(new, (int __user *)newval))
2500                         return -EFAULT;
2501                 *(int *)(table->data) = msecs_to_jiffies(new);
2502         }
2503         return 1;
2504 }
2505
2506
2507
2508 #else /* CONFIG_SYSCTL_SYSCALL */
2509
2510
2511 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2512 {
2513         static int msg_count;
2514         struct __sysctl_args tmp;
2515         int name[CTL_MAXNAME];
2516         int i;
2517
2518         /* Read in the sysctl name for better debug message logging */
2519         if (copy_from_user(&tmp, args, sizeof(tmp)))
2520                 return -EFAULT;
2521         if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2522                 return -ENOTDIR;
2523         for (i = 0; i < tmp.nlen; i++)
2524                 if (get_user(name[i], tmp.name + i))
2525                         return -EFAULT;
2526
2527         /* Ignore accesses to kernel.version */
2528         if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2529                 goto out;
2530
2531         if (msg_count < 5) {
2532                 msg_count++;
2533                 printk(KERN_INFO
2534                         "warning: process `%s' used the removed sysctl "
2535                         "system call with ", current->comm);
2536                 for (i = 0; i < tmp.nlen; i++)
2537                         printk("%d.", name[i]);
2538                 printk("\n");
2539         }
2540 out:
2541         return -ENOSYS;
2542 }
2543
2544 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2545                   void __user *oldval, size_t __user *oldlenp,
2546                   void __user *newval, size_t newlen)
2547 {
2548         return -ENOSYS;
2549 }
2550
2551 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2552                 void __user *oldval, size_t __user *oldlenp,
2553                 void __user *newval, size_t newlen)
2554 {
2555         return -ENOSYS;
2556 }
2557
2558 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2559                 void __user *oldval, size_t __user *oldlenp,
2560                 void __user *newval, size_t newlen)
2561 {
2562         return -ENOSYS;
2563 }
2564
2565 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2566                 void __user *oldval, size_t __user *oldlenp,
2567                 void __user *newval, size_t newlen)
2568 {
2569         return -ENOSYS;
2570 }
2571
2572 #endif /* CONFIG_SYSCTL_SYSCALL */
2573
2574 /*
2575  * No sense putting this after each symbol definition, twice,
2576  * exception granted :-)
2577  */
2578 EXPORT_SYMBOL(proc_dointvec);
2579 EXPORT_SYMBOL(proc_dointvec_jiffies);
2580 EXPORT_SYMBOL(proc_dointvec_minmax);
2581 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2582 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2583 EXPORT_SYMBOL(proc_dostring);
2584 EXPORT_SYMBOL(proc_doulongvec_minmax);
2585 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2586 EXPORT_SYMBOL(register_sysctl_table);
2587 EXPORT_SYMBOL(sysctl_intvec);
2588 EXPORT_SYMBOL(sysctl_jiffies);
2589 EXPORT_SYMBOL(sysctl_ms_jiffies);
2590 EXPORT_SYMBOL(sysctl_string);
2591 EXPORT_SYMBOL(unregister_sysctl_table);