2 * sysctl.c: General linux system control interface
4 * Begun 24 March 1995, Stephen Tweedie
5 * Added /proc support, Dec 1995
6 * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
7 * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
8 * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
9 * Dynamic registration fixes, Stephen Tweedie.
10 * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
11 * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
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
17 * The list_for_each() macro wasn't appropriate for the sysctl loop.
18 * Removed it and replaced it with older style, 03/23/00, Bill Wendling
21 #include <linux/module.h>
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/capability.h>
31 #include <linux/smp_lock.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>
49 #include <asm/uaccess.h>
50 #include <asm/processor.h>
52 extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
53 void __user *buffer, size_t *lenp, loff_t *ppos);
57 #include <asm/stacktrace.h>
60 #if defined(CONFIG_SYSCTL)
62 /* External variables not in a header file. */
64 extern int sysctl_overcommit_memory;
65 extern int sysctl_overcommit_ratio;
66 extern int sysctl_panic_on_oom;
67 extern int max_threads;
68 extern int sysrq_enabled;
69 extern int core_uses_pid;
70 extern int suid_dumpable;
71 extern char core_pattern[];
73 extern int min_free_kbytes;
74 extern int printk_ratelimit_jiffies;
75 extern int printk_ratelimit_burst;
76 extern int pid_max_min, pid_max_max;
77 extern int sysctl_drop_caches;
78 extern int percpu_pagelist_fraction;
79 extern int compat_log;
81 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
82 static int maxolduid = 65535;
84 static int min_percpu_pagelist_fract = 8;
86 static int ngroups_max = NGROUPS_MAX;
89 extern char modprobe_path[];
91 #ifdef CONFIG_CHR_DEV_SG
92 extern int sg_big_buff;
95 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
96 void __user *buffer, size_t *lenp, loff_t *ppos);
97 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
98 void __user *buffer, size_t *lenp, loff_t *ppos);
102 extern char reboot_command [];
103 extern int stop_a_enabled;
104 extern int scons_pwroff;
108 extern int pwrsw_enabled;
109 extern int unaligned_enabled;
113 #ifdef CONFIG_MATHEMU
114 extern int sysctl_ieee_emulation_warnings;
116 extern int sysctl_userprocess_debug;
117 extern int spin_retry;
120 extern int sysctl_hz_timer;
122 #ifdef CONFIG_BSD_PROCESS_ACCT
123 extern int acct_parm[];
127 extern int no_unaligned_warning;
130 #ifdef CONFIG_RT_MUTEXES
131 extern int max_lock_depth;
134 #ifdef CONFIG_SYSCTL_SYSCALL
135 static int parse_table(int __user *, int, void __user *, size_t __user *,
136 void __user *, size_t, ctl_table *, void **);
139 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
140 void __user *buffer, size_t *lenp, loff_t *ppos);
142 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
143 void __user *oldval, size_t __user *oldlenp,
144 void __user *newval, size_t newlen, void **context);
146 #ifdef CONFIG_PROC_SYSCTL
147 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
148 void __user *buffer, size_t *lenp, loff_t *ppos);
151 static ctl_table root_table[];
152 static struct ctl_table_header root_table_header =
153 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
155 static ctl_table kern_table[];
156 static ctl_table vm_table[];
157 static ctl_table fs_table[];
158 static ctl_table debug_table[];
159 static ctl_table dev_table[];
160 extern ctl_table random_table[];
161 #ifdef CONFIG_UNIX98_PTYS
162 extern ctl_table pty_table[];
164 #ifdef CONFIG_INOTIFY_USER
165 extern ctl_table inotify_table[];
168 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
169 int sysctl_legacy_va_layout;
172 static void *get_uts(ctl_table *table, int write)
174 char *which = table->data;
176 struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
177 which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
182 down_write(&uts_sem);
186 static void put_uts(ctl_table *table, int write, void *which)
194 #ifdef CONFIG_SYSVIPC
195 static void *get_ipc(ctl_table *table, int write)
197 char *which = table->data;
198 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
199 which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
203 #define get_ipc(T,W) ((T)->data)
206 /* /proc declarations: */
208 #ifdef CONFIG_PROC_SYSCTL
210 static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
211 static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
212 static int proc_opensys(struct inode *, struct file *);
214 const struct file_operations proc_sys_file_operations = {
215 .open = proc_opensys,
216 .read = proc_readsys,
217 .write = proc_writesys,
220 extern struct proc_dir_entry *proc_sys_root;
222 static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
223 static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
226 /* The default sysctl tables: */
228 static ctl_table root_table[] = {
230 .ctl_name = CTL_KERN,
231 .procname = "kernel",
256 .ctl_name = CTL_DEBUG,
259 .child = debug_table,
271 static ctl_table kern_table[] = {
273 .ctl_name = KERN_OSTYPE,
274 .procname = "ostype",
275 .data = init_uts_ns.name.sysname,
276 .maxlen = sizeof(init_uts_ns.name.sysname),
278 .proc_handler = &proc_do_uts_string,
279 .strategy = &sysctl_uts_string,
282 .ctl_name = KERN_OSRELEASE,
283 .procname = "osrelease",
284 .data = init_uts_ns.name.release,
285 .maxlen = sizeof(init_uts_ns.name.release),
287 .proc_handler = &proc_do_uts_string,
288 .strategy = &sysctl_uts_string,
291 .ctl_name = KERN_VERSION,
292 .procname = "version",
293 .data = init_uts_ns.name.version,
294 .maxlen = sizeof(init_uts_ns.name.version),
296 .proc_handler = &proc_do_uts_string,
297 .strategy = &sysctl_uts_string,
300 .ctl_name = KERN_NODENAME,
301 .procname = "hostname",
302 .data = init_uts_ns.name.nodename,
303 .maxlen = sizeof(init_uts_ns.name.nodename),
305 .proc_handler = &proc_do_uts_string,
306 .strategy = &sysctl_uts_string,
309 .ctl_name = KERN_DOMAINNAME,
310 .procname = "domainname",
311 .data = init_uts_ns.name.domainname,
312 .maxlen = sizeof(init_uts_ns.name.domainname),
314 .proc_handler = &proc_do_uts_string,
315 .strategy = &sysctl_uts_string,
318 .ctl_name = KERN_PANIC,
320 .data = &panic_timeout,
321 .maxlen = sizeof(int),
323 .proc_handler = &proc_dointvec,
326 .ctl_name = KERN_CORE_USES_PID,
327 .procname = "core_uses_pid",
328 .data = &core_uses_pid,
329 .maxlen = sizeof(int),
331 .proc_handler = &proc_dointvec,
334 .ctl_name = KERN_CORE_PATTERN,
335 .procname = "core_pattern",
336 .data = core_pattern,
339 .proc_handler = &proc_dostring,
340 .strategy = &sysctl_string,
343 .ctl_name = KERN_TAINTED,
344 .procname = "tainted",
346 .maxlen = sizeof(int),
348 .proc_handler = &proc_dointvec,
351 .ctl_name = KERN_CAP_BSET,
352 .procname = "cap-bound",
354 .maxlen = sizeof(kernel_cap_t),
356 .proc_handler = &proc_dointvec_bset,
358 #ifdef CONFIG_BLK_DEV_INITRD
360 .ctl_name = KERN_REALROOTDEV,
361 .procname = "real-root-dev",
362 .data = &real_root_dev,
363 .maxlen = sizeof(int),
365 .proc_handler = &proc_dointvec,
370 .ctl_name = KERN_SPARC_REBOOT,
371 .procname = "reboot-cmd",
372 .data = reboot_command,
375 .proc_handler = &proc_dostring,
376 .strategy = &sysctl_string,
379 .ctl_name = KERN_SPARC_STOP_A,
380 .procname = "stop-a",
381 .data = &stop_a_enabled,
382 .maxlen = sizeof (int),
384 .proc_handler = &proc_dointvec,
387 .ctl_name = KERN_SPARC_SCONS_PWROFF,
388 .procname = "scons-poweroff",
389 .data = &scons_pwroff,
390 .maxlen = sizeof (int),
392 .proc_handler = &proc_dointvec,
397 .ctl_name = KERN_HPPA_PWRSW,
398 .procname = "soft-power",
399 .data = &pwrsw_enabled,
400 .maxlen = sizeof (int),
402 .proc_handler = &proc_dointvec,
405 .ctl_name = KERN_HPPA_UNALIGNED,
406 .procname = "unaligned-trap",
407 .data = &unaligned_enabled,
408 .maxlen = sizeof (int),
410 .proc_handler = &proc_dointvec,
414 .ctl_name = KERN_CTLALTDEL,
415 .procname = "ctrl-alt-del",
417 .maxlen = sizeof(int),
419 .proc_handler = &proc_dointvec,
422 .ctl_name = KERN_PRINTK,
423 .procname = "printk",
424 .data = &console_loglevel,
425 .maxlen = 4*sizeof(int),
427 .proc_handler = &proc_dointvec,
431 .ctl_name = KERN_MODPROBE,
432 .procname = "modprobe",
433 .data = &modprobe_path,
434 .maxlen = KMOD_PATH_LEN,
436 .proc_handler = &proc_dostring,
437 .strategy = &sysctl_string,
440 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
442 .ctl_name = KERN_HOTPLUG,
443 .procname = "hotplug",
444 .data = &uevent_helper,
445 .maxlen = UEVENT_HELPER_PATH_LEN,
447 .proc_handler = &proc_dostring,
448 .strategy = &sysctl_string,
451 #ifdef CONFIG_CHR_DEV_SG
453 .ctl_name = KERN_SG_BIG_BUFF,
454 .procname = "sg-big-buff",
455 .data = &sg_big_buff,
456 .maxlen = sizeof (int),
458 .proc_handler = &proc_dointvec,
461 #ifdef CONFIG_BSD_PROCESS_ACCT
463 .ctl_name = KERN_ACCT,
466 .maxlen = 3*sizeof(int),
468 .proc_handler = &proc_dointvec,
471 #ifdef CONFIG_SYSVIPC
473 .ctl_name = KERN_SHMMAX,
474 .procname = "shmmax",
475 .data = &init_ipc_ns.shm_ctlmax,
476 .maxlen = sizeof (init_ipc_ns.shm_ctlmax),
478 .proc_handler = &proc_ipc_doulongvec_minmax,
481 .ctl_name = KERN_SHMALL,
482 .procname = "shmall",
483 .data = &init_ipc_ns.shm_ctlall,
484 .maxlen = sizeof (init_ipc_ns.shm_ctlall),
486 .proc_handler = &proc_ipc_doulongvec_minmax,
489 .ctl_name = KERN_SHMMNI,
490 .procname = "shmmni",
491 .data = &init_ipc_ns.shm_ctlmni,
492 .maxlen = sizeof (init_ipc_ns.shm_ctlmni),
494 .proc_handler = &proc_ipc_dointvec,
497 .ctl_name = KERN_MSGMAX,
498 .procname = "msgmax",
499 .data = &init_ipc_ns.msg_ctlmax,
500 .maxlen = sizeof (init_ipc_ns.msg_ctlmax),
502 .proc_handler = &proc_ipc_dointvec,
505 .ctl_name = KERN_MSGMNI,
506 .procname = "msgmni",
507 .data = &init_ipc_ns.msg_ctlmni,
508 .maxlen = sizeof (init_ipc_ns.msg_ctlmni),
510 .proc_handler = &proc_ipc_dointvec,
513 .ctl_name = KERN_MSGMNB,
514 .procname = "msgmnb",
515 .data = &init_ipc_ns.msg_ctlmnb,
516 .maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
518 .proc_handler = &proc_ipc_dointvec,
521 .ctl_name = KERN_SEM,
523 .data = &init_ipc_ns.sem_ctls,
524 .maxlen = 4*sizeof (int),
526 .proc_handler = &proc_ipc_dointvec,
529 #ifdef CONFIG_MAGIC_SYSRQ
531 .ctl_name = KERN_SYSRQ,
533 .data = &sysrq_enabled,
534 .maxlen = sizeof (int),
536 .proc_handler = &proc_dointvec,
539 #ifdef CONFIG_PROC_SYSCTL
541 .ctl_name = KERN_CADPID,
542 .procname = "cad_pid",
544 .maxlen = sizeof (int),
546 .proc_handler = &proc_do_cad_pid,
550 .ctl_name = KERN_MAX_THREADS,
551 .procname = "threads-max",
552 .data = &max_threads,
553 .maxlen = sizeof(int),
555 .proc_handler = &proc_dointvec,
558 .ctl_name = KERN_RANDOM,
559 .procname = "random",
561 .child = random_table,
563 #ifdef CONFIG_UNIX98_PTYS
565 .ctl_name = KERN_PTY,
572 .ctl_name = KERN_OVERFLOWUID,
573 .procname = "overflowuid",
574 .data = &overflowuid,
575 .maxlen = sizeof(int),
577 .proc_handler = &proc_dointvec_minmax,
578 .strategy = &sysctl_intvec,
579 .extra1 = &minolduid,
580 .extra2 = &maxolduid,
583 .ctl_name = KERN_OVERFLOWGID,
584 .procname = "overflowgid",
585 .data = &overflowgid,
586 .maxlen = sizeof(int),
588 .proc_handler = &proc_dointvec_minmax,
589 .strategy = &sysctl_intvec,
590 .extra1 = &minolduid,
591 .extra2 = &maxolduid,
594 #ifdef CONFIG_MATHEMU
596 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
597 .procname = "ieee_emulation_warnings",
598 .data = &sysctl_ieee_emulation_warnings,
599 .maxlen = sizeof(int),
601 .proc_handler = &proc_dointvec,
604 #ifdef CONFIG_NO_IDLE_HZ
606 .ctl_name = KERN_HZ_TIMER,
607 .procname = "hz_timer",
608 .data = &sysctl_hz_timer,
609 .maxlen = sizeof(int),
611 .proc_handler = &proc_dointvec,
615 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
616 .procname = "userprocess_debug",
617 .data = &sysctl_userprocess_debug,
618 .maxlen = sizeof(int),
620 .proc_handler = &proc_dointvec,
624 .ctl_name = KERN_PIDMAX,
625 .procname = "pid_max",
627 .maxlen = sizeof (int),
629 .proc_handler = &proc_dointvec_minmax,
630 .strategy = sysctl_intvec,
631 .extra1 = &pid_max_min,
632 .extra2 = &pid_max_max,
635 .ctl_name = KERN_PANIC_ON_OOPS,
636 .procname = "panic_on_oops",
637 .data = &panic_on_oops,
638 .maxlen = sizeof(int),
640 .proc_handler = &proc_dointvec,
643 .ctl_name = KERN_PRINTK_RATELIMIT,
644 .procname = "printk_ratelimit",
645 .data = &printk_ratelimit_jiffies,
646 .maxlen = sizeof(int),
648 .proc_handler = &proc_dointvec_jiffies,
649 .strategy = &sysctl_jiffies,
652 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
653 .procname = "printk_ratelimit_burst",
654 .data = &printk_ratelimit_burst,
655 .maxlen = sizeof(int),
657 .proc_handler = &proc_dointvec,
660 .ctl_name = KERN_NGROUPS_MAX,
661 .procname = "ngroups_max",
662 .data = &ngroups_max,
663 .maxlen = sizeof (int),
665 .proc_handler = &proc_dointvec,
667 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
669 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
670 .procname = "unknown_nmi_panic",
671 .data = &unknown_nmi_panic,
672 .maxlen = sizeof (int),
674 .proc_handler = &proc_dointvec,
677 .ctl_name = KERN_NMI_WATCHDOG,
678 .procname = "nmi_watchdog",
679 .data = &nmi_watchdog_enabled,
680 .maxlen = sizeof (int),
682 .proc_handler = &proc_nmi_enabled,
685 #if defined(CONFIG_X86)
687 .ctl_name = KERN_PANIC_ON_NMI,
688 .procname = "panic_on_unrecovered_nmi",
689 .data = &panic_on_unrecovered_nmi,
690 .maxlen = sizeof(int),
692 .proc_handler = &proc_dointvec,
695 .ctl_name = KERN_BOOTLOADER_TYPE,
696 .procname = "bootloader_type",
697 .data = &bootloader_type,
698 .maxlen = sizeof (int),
700 .proc_handler = &proc_dointvec,
703 .ctl_name = CTL_UNNUMBERED,
704 .procname = "kstack_depth_to_print",
705 .data = &kstack_depth_to_print,
706 .maxlen = sizeof(int),
708 .proc_handler = &proc_dointvec,
711 #if defined(CONFIG_MMU)
713 .ctl_name = KERN_RANDOMIZE,
714 .procname = "randomize_va_space",
715 .data = &randomize_va_space,
716 .maxlen = sizeof(int),
718 .proc_handler = &proc_dointvec,
721 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
723 .ctl_name = KERN_SPIN_RETRY,
724 .procname = "spin_retry",
726 .maxlen = sizeof (int),
728 .proc_handler = &proc_dointvec,
731 #ifdef CONFIG_ACPI_SLEEP
733 .ctl_name = KERN_ACPI_VIDEO_FLAGS,
734 .procname = "acpi_video_flags",
735 .data = &acpi_video_flags,
736 .maxlen = sizeof (unsigned long),
738 .proc_handler = &proc_doulongvec_minmax,
743 .ctl_name = KERN_IA64_UNALIGNED,
744 .procname = "ignore-unaligned-usertrap",
745 .data = &no_unaligned_warning,
746 .maxlen = sizeof (int),
748 .proc_handler = &proc_dointvec,
753 .ctl_name = KERN_COMPAT_LOG,
754 .procname = "compat-log",
756 .maxlen = sizeof (int),
758 .proc_handler = &proc_dointvec,
761 #ifdef CONFIG_RT_MUTEXES
763 .ctl_name = KERN_MAX_LOCK_DEPTH,
764 .procname = "max_lock_depth",
765 .data = &max_lock_depth,
766 .maxlen = sizeof(int),
768 .proc_handler = &proc_dointvec,
775 /* Constants for minimum and maximum testing in vm_table.
776 We use these as one-element integer vectors. */
778 static int one_hundred = 100;
781 static ctl_table vm_table[] = {
783 .ctl_name = VM_OVERCOMMIT_MEMORY,
784 .procname = "overcommit_memory",
785 .data = &sysctl_overcommit_memory,
786 .maxlen = sizeof(sysctl_overcommit_memory),
788 .proc_handler = &proc_dointvec,
791 .ctl_name = VM_PANIC_ON_OOM,
792 .procname = "panic_on_oom",
793 .data = &sysctl_panic_on_oom,
794 .maxlen = sizeof(sysctl_panic_on_oom),
796 .proc_handler = &proc_dointvec,
799 .ctl_name = VM_OVERCOMMIT_RATIO,
800 .procname = "overcommit_ratio",
801 .data = &sysctl_overcommit_ratio,
802 .maxlen = sizeof(sysctl_overcommit_ratio),
804 .proc_handler = &proc_dointvec,
807 .ctl_name = VM_PAGE_CLUSTER,
808 .procname = "page-cluster",
809 .data = &page_cluster,
810 .maxlen = sizeof(int),
812 .proc_handler = &proc_dointvec,
815 .ctl_name = VM_DIRTY_BACKGROUND,
816 .procname = "dirty_background_ratio",
817 .data = &dirty_background_ratio,
818 .maxlen = sizeof(dirty_background_ratio),
820 .proc_handler = &proc_dointvec_minmax,
821 .strategy = &sysctl_intvec,
823 .extra2 = &one_hundred,
826 .ctl_name = VM_DIRTY_RATIO,
827 .procname = "dirty_ratio",
828 .data = &vm_dirty_ratio,
829 .maxlen = sizeof(vm_dirty_ratio),
831 .proc_handler = &proc_dointvec_minmax,
832 .strategy = &sysctl_intvec,
834 .extra2 = &one_hundred,
837 .ctl_name = VM_DIRTY_WB_CS,
838 .procname = "dirty_writeback_centisecs",
839 .data = &dirty_writeback_interval,
840 .maxlen = sizeof(dirty_writeback_interval),
842 .proc_handler = &dirty_writeback_centisecs_handler,
845 .ctl_name = VM_DIRTY_EXPIRE_CS,
846 .procname = "dirty_expire_centisecs",
847 .data = &dirty_expire_interval,
848 .maxlen = sizeof(dirty_expire_interval),
850 .proc_handler = &proc_dointvec_userhz_jiffies,
853 .ctl_name = VM_NR_PDFLUSH_THREADS,
854 .procname = "nr_pdflush_threads",
855 .data = &nr_pdflush_threads,
856 .maxlen = sizeof nr_pdflush_threads,
857 .mode = 0444 /* read-only*/,
858 .proc_handler = &proc_dointvec,
861 .ctl_name = VM_SWAPPINESS,
862 .procname = "swappiness",
863 .data = &vm_swappiness,
864 .maxlen = sizeof(vm_swappiness),
866 .proc_handler = &proc_dointvec_minmax,
867 .strategy = &sysctl_intvec,
869 .extra2 = &one_hundred,
871 #ifdef CONFIG_HUGETLB_PAGE
873 .ctl_name = VM_HUGETLB_PAGES,
874 .procname = "nr_hugepages",
875 .data = &max_huge_pages,
876 .maxlen = sizeof(unsigned long),
878 .proc_handler = &hugetlb_sysctl_handler,
879 .extra1 = (void *)&hugetlb_zero,
880 .extra2 = (void *)&hugetlb_infinity,
883 .ctl_name = VM_HUGETLB_GROUP,
884 .procname = "hugetlb_shm_group",
885 .data = &sysctl_hugetlb_shm_group,
886 .maxlen = sizeof(gid_t),
888 .proc_handler = &proc_dointvec,
892 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
893 .procname = "lowmem_reserve_ratio",
894 .data = &sysctl_lowmem_reserve_ratio,
895 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
897 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
898 .strategy = &sysctl_intvec,
901 .ctl_name = VM_DROP_PAGECACHE,
902 .procname = "drop_caches",
903 .data = &sysctl_drop_caches,
904 .maxlen = sizeof(int),
906 .proc_handler = drop_caches_sysctl_handler,
907 .strategy = &sysctl_intvec,
910 .ctl_name = VM_MIN_FREE_KBYTES,
911 .procname = "min_free_kbytes",
912 .data = &min_free_kbytes,
913 .maxlen = sizeof(min_free_kbytes),
915 .proc_handler = &min_free_kbytes_sysctl_handler,
916 .strategy = &sysctl_intvec,
920 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
921 .procname = "percpu_pagelist_fraction",
922 .data = &percpu_pagelist_fraction,
923 .maxlen = sizeof(percpu_pagelist_fraction),
925 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
926 .strategy = &sysctl_intvec,
927 .extra1 = &min_percpu_pagelist_fract,
931 .ctl_name = VM_MAX_MAP_COUNT,
932 .procname = "max_map_count",
933 .data = &sysctl_max_map_count,
934 .maxlen = sizeof(sysctl_max_map_count),
936 .proc_handler = &proc_dointvec
940 .ctl_name = VM_LAPTOP_MODE,
941 .procname = "laptop_mode",
942 .data = &laptop_mode,
943 .maxlen = sizeof(laptop_mode),
945 .proc_handler = &proc_dointvec_jiffies,
946 .strategy = &sysctl_jiffies,
949 .ctl_name = VM_BLOCK_DUMP,
950 .procname = "block_dump",
952 .maxlen = sizeof(block_dump),
954 .proc_handler = &proc_dointvec,
955 .strategy = &sysctl_intvec,
959 .ctl_name = VM_VFS_CACHE_PRESSURE,
960 .procname = "vfs_cache_pressure",
961 .data = &sysctl_vfs_cache_pressure,
962 .maxlen = sizeof(sysctl_vfs_cache_pressure),
964 .proc_handler = &proc_dointvec,
965 .strategy = &sysctl_intvec,
968 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
970 .ctl_name = VM_LEGACY_VA_LAYOUT,
971 .procname = "legacy_va_layout",
972 .data = &sysctl_legacy_va_layout,
973 .maxlen = sizeof(sysctl_legacy_va_layout),
975 .proc_handler = &proc_dointvec,
976 .strategy = &sysctl_intvec,
982 .ctl_name = VM_ZONE_RECLAIM_MODE,
983 .procname = "zone_reclaim_mode",
984 .data = &zone_reclaim_mode,
985 .maxlen = sizeof(zone_reclaim_mode),
987 .proc_handler = &proc_dointvec,
988 .strategy = &sysctl_intvec,
992 .ctl_name = VM_MIN_UNMAPPED,
993 .procname = "min_unmapped_ratio",
994 .data = &sysctl_min_unmapped_ratio,
995 .maxlen = sizeof(sysctl_min_unmapped_ratio),
997 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
998 .strategy = &sysctl_intvec,
1000 .extra2 = &one_hundred,
1003 .ctl_name = VM_MIN_SLAB,
1004 .procname = "min_slab_ratio",
1005 .data = &sysctl_min_slab_ratio,
1006 .maxlen = sizeof(sysctl_min_slab_ratio),
1008 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1009 .strategy = &sysctl_intvec,
1011 .extra2 = &one_hundred,
1014 #ifdef CONFIG_X86_32
1016 .ctl_name = VM_VDSO_ENABLED,
1017 .procname = "vdso_enabled",
1018 .data = &vdso_enabled,
1019 .maxlen = sizeof(vdso_enabled),
1021 .proc_handler = &proc_dointvec,
1022 .strategy = &sysctl_intvec,
1029 static ctl_table fs_table[] = {
1031 .ctl_name = FS_NRINODE,
1032 .procname = "inode-nr",
1033 .data = &inodes_stat,
1034 .maxlen = 2*sizeof(int),
1036 .proc_handler = &proc_dointvec,
1039 .ctl_name = FS_STATINODE,
1040 .procname = "inode-state",
1041 .data = &inodes_stat,
1042 .maxlen = 7*sizeof(int),
1044 .proc_handler = &proc_dointvec,
1047 .ctl_name = FS_NRFILE,
1048 .procname = "file-nr",
1049 .data = &files_stat,
1050 .maxlen = 3*sizeof(int),
1052 .proc_handler = &proc_nr_files,
1055 .ctl_name = FS_MAXFILE,
1056 .procname = "file-max",
1057 .data = &files_stat.max_files,
1058 .maxlen = sizeof(int),
1060 .proc_handler = &proc_dointvec,
1063 .ctl_name = FS_DENTRY,
1064 .procname = "dentry-state",
1065 .data = &dentry_stat,
1066 .maxlen = 6*sizeof(int),
1068 .proc_handler = &proc_dointvec,
1071 .ctl_name = FS_OVERFLOWUID,
1072 .procname = "overflowuid",
1073 .data = &fs_overflowuid,
1074 .maxlen = sizeof(int),
1076 .proc_handler = &proc_dointvec_minmax,
1077 .strategy = &sysctl_intvec,
1078 .extra1 = &minolduid,
1079 .extra2 = &maxolduid,
1082 .ctl_name = FS_OVERFLOWGID,
1083 .procname = "overflowgid",
1084 .data = &fs_overflowgid,
1085 .maxlen = sizeof(int),
1087 .proc_handler = &proc_dointvec_minmax,
1088 .strategy = &sysctl_intvec,
1089 .extra1 = &minolduid,
1090 .extra2 = &maxolduid,
1093 .ctl_name = FS_LEASES,
1094 .procname = "leases-enable",
1095 .data = &leases_enable,
1096 .maxlen = sizeof(int),
1098 .proc_handler = &proc_dointvec,
1100 #ifdef CONFIG_DNOTIFY
1102 .ctl_name = FS_DIR_NOTIFY,
1103 .procname = "dir-notify-enable",
1104 .data = &dir_notify_enable,
1105 .maxlen = sizeof(int),
1107 .proc_handler = &proc_dointvec,
1112 .ctl_name = FS_LEASE_TIME,
1113 .procname = "lease-break-time",
1114 .data = &lease_break_time,
1115 .maxlen = sizeof(int),
1117 .proc_handler = &proc_dointvec,
1120 .ctl_name = FS_AIO_NR,
1121 .procname = "aio-nr",
1123 .maxlen = sizeof(aio_nr),
1125 .proc_handler = &proc_doulongvec_minmax,
1128 .ctl_name = FS_AIO_MAX_NR,
1129 .procname = "aio-max-nr",
1130 .data = &aio_max_nr,
1131 .maxlen = sizeof(aio_max_nr),
1133 .proc_handler = &proc_doulongvec_minmax,
1135 #ifdef CONFIG_INOTIFY_USER
1137 .ctl_name = FS_INOTIFY,
1138 .procname = "inotify",
1140 .child = inotify_table,
1145 .ctl_name = KERN_SETUID_DUMPABLE,
1146 .procname = "suid_dumpable",
1147 .data = &suid_dumpable,
1148 .maxlen = sizeof(int),
1150 .proc_handler = &proc_dointvec,
1155 static ctl_table debug_table[] = {
1159 static ctl_table dev_table[] = {
1163 extern void init_irq_proc (void);
1165 static DEFINE_SPINLOCK(sysctl_lock);
1167 /* called under sysctl_lock */
1168 static int use_table(struct ctl_table_header *p)
1170 if (unlikely(p->unregistering))
1176 /* called under sysctl_lock */
1177 static void unuse_table(struct ctl_table_header *p)
1180 if (unlikely(p->unregistering))
1181 complete(p->unregistering);
1184 /* called under sysctl_lock, will reacquire if has to wait */
1185 static void start_unregistering(struct ctl_table_header *p)
1188 * if p->used is 0, nobody will ever touch that entry again;
1189 * we'll eliminate all paths to it before dropping sysctl_lock
1191 if (unlikely(p->used)) {
1192 struct completion wait;
1193 init_completion(&wait);
1194 p->unregistering = &wait;
1195 spin_unlock(&sysctl_lock);
1196 wait_for_completion(&wait);
1197 spin_lock(&sysctl_lock);
1200 * do not remove from the list until nobody holds it; walking the
1201 * list in do_sysctl() relies on that.
1203 list_del_init(&p->ctl_entry);
1206 void __init sysctl_init(void)
1208 #ifdef CONFIG_PROC_SYSCTL
1209 register_proc_table(root_table, proc_sys_root, &root_table_header);
1214 #ifdef CONFIG_SYSCTL_SYSCALL
1215 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1216 void __user *newval, size_t newlen)
1218 struct list_head *tmp;
1219 int error = -ENOTDIR;
1221 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1225 if (!oldlenp || get_user(old_len, oldlenp))
1228 spin_lock(&sysctl_lock);
1229 tmp = &root_table_header.ctl_entry;
1231 struct ctl_table_header *head =
1232 list_entry(tmp, struct ctl_table_header, ctl_entry);
1233 void *context = NULL;
1235 if (!use_table(head))
1238 spin_unlock(&sysctl_lock);
1240 error = parse_table(name, nlen, oldval, oldlenp,
1241 newval, newlen, head->ctl_table,
1245 spin_lock(&sysctl_lock);
1247 if (error != -ENOTDIR)
1249 } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
1250 spin_unlock(&sysctl_lock);
1254 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1256 struct __sysctl_args tmp;
1259 if (copy_from_user(&tmp, args, sizeof(tmp)))
1263 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1264 tmp.newval, tmp.newlen);
1268 #endif /* CONFIG_SYSCTL_SYSCALL */
1271 * ctl_perm does NOT grant the superuser all rights automatically, because
1272 * some sysctl variables are readonly even to root.
1275 static int test_perm(int mode, int op)
1279 else if (in_egroup_p(0))
1281 if ((mode & op & 0007) == op)
1286 static inline int ctl_perm(ctl_table *table, int op)
1289 error = security_sysctl(table, op);
1292 return test_perm(table->mode, op);
1295 #ifdef CONFIG_SYSCTL_SYSCALL
1296 static int parse_table(int __user *name, int nlen,
1297 void __user *oldval, size_t __user *oldlenp,
1298 void __user *newval, size_t newlen,
1299 ctl_table *table, void **context)
1305 if (get_user(n, name))
1307 for ( ; table->ctl_name || table->procname; table++) {
1308 if (!table->ctl_name)
1310 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1313 if (ctl_perm(table, 001))
1315 if (table->strategy) {
1316 error = table->strategy(
1319 newval, newlen, context);
1325 table = table->child;
1328 error = do_sysctl_strategy(table, name, nlen,
1330 newval, newlen, context);
1337 /* Perform the actual read/write of a sysctl table entry. */
1338 int do_sysctl_strategy (ctl_table *table,
1339 int __user *name, int nlen,
1340 void __user *oldval, size_t __user *oldlenp,
1341 void __user *newval, size_t newlen, void **context)
1350 if (ctl_perm(table, op))
1353 if (table->strategy) {
1354 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1355 newval, newlen, context);
1362 /* If there is no strategy routine, or if the strategy returns
1363 * zero, proceed with automatic r/w */
1364 if (table->data && table->maxlen) {
1365 if (oldval && oldlenp) {
1366 if (get_user(len, oldlenp))
1369 if (len > table->maxlen)
1370 len = table->maxlen;
1371 if(copy_to_user(oldval, table->data, len))
1373 if(put_user(len, oldlenp))
1377 if (newval && newlen) {
1379 if (len > table->maxlen)
1380 len = table->maxlen;
1381 if(copy_from_user(table->data, newval, len))
1387 #endif /* CONFIG_SYSCTL_SYSCALL */
1390 * register_sysctl_table - register a sysctl hierarchy
1391 * @table: the top-level table structure
1392 * @insert_at_head: whether the entry should be inserted in front or at the end
1394 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1395 * array. An entry with a ctl_name of 0 terminates the table.
1397 * The members of the &ctl_table structure are used as follows:
1399 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1400 * must be unique within that level of sysctl
1402 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1403 * enter a sysctl file
1405 * data - a pointer to data for use by proc_handler
1407 * maxlen - the maximum size in bytes of the data
1409 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1411 * child - a pointer to the child sysctl table if this entry is a directory, or
1414 * proc_handler - the text handler routine (described below)
1416 * strategy - the strategy routine (described below)
1418 * de - for internal use by the sysctl routines
1420 * extra1, extra2 - extra pointers usable by the proc handler routines
1422 * Leaf nodes in the sysctl tree will be represented by a single file
1423 * under /proc; non-leaf nodes will be represented by directories.
1425 * sysctl(2) can automatically manage read and write requests through
1426 * the sysctl table. The data and maxlen fields of the ctl_table
1427 * struct enable minimal validation of the values being written to be
1428 * performed, and the mode field allows minimal authentication.
1430 * More sophisticated management can be enabled by the provision of a
1431 * strategy routine with the table entry. This will be called before
1432 * any automatic read or write of the data is performed.
1434 * The strategy routine may return
1436 * < 0 - Error occurred (error is passed to user process)
1438 * 0 - OK - proceed with automatic read or write.
1440 * > 0 - OK - read or write has been done by the strategy routine, so
1441 * return immediately.
1443 * There must be a proc_handler routine for any terminal nodes
1444 * mirrored under /proc/sys (non-terminals are handled by a built-in
1445 * directory handler). Several default handlers are available to
1446 * cover common cases -
1448 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1449 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1450 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1452 * It is the handler's job to read the input buffer from user memory
1453 * and process it. The handler should return 0 on success.
1455 * This routine returns %NULL on a failure to register, and a pointer
1456 * to the table header on success.
1458 struct ctl_table_header *register_sysctl_table(ctl_table * table,
1461 struct ctl_table_header *tmp;
1462 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1465 tmp->ctl_table = table;
1466 INIT_LIST_HEAD(&tmp->ctl_entry);
1468 tmp->unregistering = NULL;
1469 spin_lock(&sysctl_lock);
1471 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1473 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1474 spin_unlock(&sysctl_lock);
1475 #ifdef CONFIG_PROC_SYSCTL
1476 register_proc_table(table, proc_sys_root, tmp);
1482 * unregister_sysctl_table - unregister a sysctl table hierarchy
1483 * @header: the header returned from register_sysctl_table
1485 * Unregisters the sysctl table and all children. proc entries may not
1486 * actually be removed until they are no longer used by anyone.
1488 void unregister_sysctl_table(struct ctl_table_header * header)
1491 spin_lock(&sysctl_lock);
1492 start_unregistering(header);
1493 #ifdef CONFIG_PROC_SYSCTL
1494 unregister_proc_table(header->ctl_table, proc_sys_root);
1496 spin_unlock(&sysctl_lock);
1500 #else /* !CONFIG_SYSCTL */
1501 struct ctl_table_header * register_sysctl_table(ctl_table * table,
1507 void unregister_sysctl_table(struct ctl_table_header * table)
1511 #endif /* CONFIG_SYSCTL */
1517 #ifdef CONFIG_PROC_SYSCTL
1519 /* Scan the sysctl entries in table and add them all into /proc */
1520 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
1522 struct proc_dir_entry *de;
1526 for (; table->ctl_name || table->procname; table++) {
1527 /* Can't do anything without a proc name. */
1528 if (!table->procname)
1530 /* Maybe we can't do anything with it... */
1531 if (!table->proc_handler && !table->child) {
1532 printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1537 len = strlen(table->procname);
1541 if (table->proc_handler)
1545 for (de = root->subdir; de; de = de->next) {
1546 if (proc_match(len, table->procname, de))
1549 /* If the subdir exists already, de is non-NULL */
1553 de = create_proc_entry(table->procname, mode, root);
1557 de->data = (void *) table;
1558 if (table->proc_handler)
1559 de->proc_fops = &proc_sys_file_operations;
1562 if (de->mode & S_IFDIR)
1563 register_proc_table(table->child, de, set);
1568 * Unregister a /proc sysctl table and any subdirectories.
1570 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1572 struct proc_dir_entry *de;
1573 for (; table->ctl_name || table->procname; table++) {
1574 if (!(de = table->de))
1576 if (de->mode & S_IFDIR) {
1577 if (!table->child) {
1578 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1581 unregister_proc_table(table->child, de);
1583 /* Don't unregister directories which still have entries.. */
1589 * In any case, mark the entry as goner; we'll keep it
1590 * around if it's busy, but we'll know to do nothing with
1591 * its fields. We are under sysctl_lock here.
1595 /* Don't unregister proc entries that are still being used.. */
1596 if (atomic_read(&de->count))
1600 remove_proc_entry(table->procname, root);
1604 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1605 size_t count, loff_t *ppos)
1608 struct proc_dir_entry *de = PDE(file->f_path.dentry->d_inode);
1609 struct ctl_table *table;
1611 ssize_t error = -ENOTDIR;
1613 spin_lock(&sysctl_lock);
1614 if (de && de->data && use_table(de->set)) {
1616 * at that point we know that sysctl was not unregistered
1617 * and won't be until we finish
1619 spin_unlock(&sysctl_lock);
1620 table = (struct ctl_table *) de->data;
1621 if (!table || !table->proc_handler)
1624 op = (write ? 002 : 004);
1625 if (ctl_perm(table, op))
1628 /* careful: calling conventions are nasty here */
1630 error = (*table->proc_handler)(table, write, file,
1635 spin_lock(&sysctl_lock);
1636 unuse_table(de->set);
1638 spin_unlock(&sysctl_lock);
1642 static int proc_opensys(struct inode *inode, struct file *file)
1644 if (file->f_mode & FMODE_WRITE) {
1646 * sysctl entries that are not writable,
1647 * are _NOT_ writable, capabilities or not.
1649 if (!(inode->i_mode & S_IWUSR))
1656 static ssize_t proc_readsys(struct file * file, char __user * buf,
1657 size_t count, loff_t *ppos)
1659 return do_rw_proc(0, file, buf, count, ppos);
1662 static ssize_t proc_writesys(struct file * file, const char __user * buf,
1663 size_t count, loff_t *ppos)
1665 return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1668 static int _proc_do_string(void* data, int maxlen, int write,
1669 struct file *filp, void __user *buffer,
1670 size_t *lenp, loff_t *ppos)
1676 if (!data || !maxlen || !*lenp ||
1677 (*ppos && !write)) {
1685 while (len < *lenp) {
1686 if (get_user(c, p++))
1688 if (c == 0 || c == '\n')
1694 if(copy_from_user(data, buffer, len))
1696 ((char *) data)[len] = 0;
1705 if(copy_to_user(buffer, data, len))
1708 if(put_user('\n', ((char __user *) buffer) + len))
1719 * proc_dostring - read a string sysctl
1720 * @table: the sysctl table
1721 * @write: %TRUE if this is a write to the sysctl file
1722 * @filp: the file structure
1723 * @buffer: the user buffer
1724 * @lenp: the size of the user buffer
1725 * @ppos: file position
1727 * Reads/writes a string from/to the user buffer. If the kernel
1728 * buffer provided is not large enough to hold the string, the
1729 * string is truncated. The copied string is %NULL-terminated.
1730 * If the string is being read by the user process, it is copied
1731 * and a newline '\n' is added. It is truncated if the buffer is
1734 * Returns 0 on success.
1736 int proc_dostring(ctl_table *table, int write, struct file *filp,
1737 void __user *buffer, size_t *lenp, loff_t *ppos)
1739 return _proc_do_string(table->data, table->maxlen, write, filp,
1740 buffer, lenp, ppos);
1744 * Special case of dostring for the UTS structure. This has locks
1745 * to observe. Should this be in kernel/sys.c ????
1748 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
1749 void __user *buffer, size_t *lenp, loff_t *ppos)
1753 which = get_uts(table, write);
1754 r = _proc_do_string(which, table->maxlen,write,filp,buffer,lenp, ppos);
1755 put_uts(table, write, which);
1759 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1761 int write, void *data)
1764 *valp = *negp ? -*lvalp : *lvalp;
1769 *lvalp = (unsigned long)-val;
1772 *lvalp = (unsigned long)val;
1778 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1779 int write, struct file *filp, void __user *buffer,
1780 size_t *lenp, loff_t *ppos,
1781 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1782 int write, void *data),
1785 #define TMPBUFLEN 21
1786 int *i, vleft, first=1, neg, val;
1790 char buf[TMPBUFLEN], *p;
1791 char __user *s = buffer;
1793 if (!tbl_data || !table->maxlen || !*lenp ||
1794 (*ppos && !write)) {
1799 i = (int *) tbl_data;
1800 vleft = table->maxlen / sizeof(*i);
1804 conv = do_proc_dointvec_conv;
1806 for (; left && vleft--; i++, first=0) {
1821 if (len > sizeof(buf) - 1)
1822 len = sizeof(buf) - 1;
1823 if (copy_from_user(buf, s, len))
1827 if (*p == '-' && left > 1) {
1831 if (*p < '0' || *p > '9')
1834 lval = simple_strtoul(p, &p, 0);
1837 if ((len < left) && *p && !isspace(*p))
1844 if (conv(&neg, &lval, i, 1, data))
1851 if (conv(&neg, &lval, i, 0, data))
1854 sprintf(p, "%s%lu", neg ? "-" : "", lval);
1858 if(copy_to_user(s, buf, len))
1865 if (!write && !first && left) {
1866 if(put_user('\n', s))
1873 if (get_user(c, s++))
1888 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1889 void __user *buffer, size_t *lenp, loff_t *ppos,
1890 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1891 int write, void *data),
1894 return __do_proc_dointvec(table->data, table, write, filp,
1895 buffer, lenp, ppos, conv, data);
1899 * proc_dointvec - read a vector of integers
1900 * @table: the sysctl table
1901 * @write: %TRUE if this is a write to the sysctl file
1902 * @filp: the file structure
1903 * @buffer: the user buffer
1904 * @lenp: the size of the user buffer
1905 * @ppos: file position
1907 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1908 * values from/to the user buffer, treated as an ASCII string.
1910 * Returns 0 on success.
1912 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1913 void __user *buffer, size_t *lenp, loff_t *ppos)
1915 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1925 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1927 int write, void *data)
1929 int op = *(int *)data;
1931 int val = *negp ? -*lvalp : *lvalp;
1933 case OP_SET: *valp = val; break;
1934 case OP_AND: *valp &= val; break;
1935 case OP_OR: *valp |= val; break;
1936 case OP_MAX: if(*valp < val)
1939 case OP_MIN: if(*valp > val)
1947 *lvalp = (unsigned long)-val;
1950 *lvalp = (unsigned long)val;
1957 * init may raise the set.
1960 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1961 void __user *buffer, size_t *lenp, loff_t *ppos)
1965 if (!capable(CAP_SYS_MODULE)) {
1969 op = is_init(current) ? OP_SET : OP_AND;
1970 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1971 do_proc_dointvec_bset_conv,&op);
1974 struct do_proc_dointvec_minmax_conv_param {
1979 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1981 int write, void *data)
1983 struct do_proc_dointvec_minmax_conv_param *param = data;
1985 int val = *negp ? -*lvalp : *lvalp;
1986 if ((param->min && *param->min > val) ||
1987 (param->max && *param->max < val))
1994 *lvalp = (unsigned long)-val;
1997 *lvalp = (unsigned long)val;
2004 * proc_dointvec_minmax - read a vector of integers with min/max values
2005 * @table: the sysctl table
2006 * @write: %TRUE if this is a write to the sysctl file
2007 * @filp: the file structure
2008 * @buffer: the user buffer
2009 * @lenp: the size of the user buffer
2010 * @ppos: file position
2012 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2013 * values from/to the user buffer, treated as an ASCII string.
2015 * This routine will ensure the values are within the range specified by
2016 * table->extra1 (min) and table->extra2 (max).
2018 * Returns 0 on success.
2020 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2021 void __user *buffer, size_t *lenp, loff_t *ppos)
2023 struct do_proc_dointvec_minmax_conv_param param = {
2024 .min = (int *) table->extra1,
2025 .max = (int *) table->extra2,
2027 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2028 do_proc_dointvec_minmax_conv, ¶m);
2031 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
2033 void __user *buffer,
2034 size_t *lenp, loff_t *ppos,
2035 unsigned long convmul,
2036 unsigned long convdiv)
2038 #define TMPBUFLEN 21
2039 unsigned long *i, *min, *max, val;
2040 int vleft, first=1, neg;
2042 char buf[TMPBUFLEN], *p;
2043 char __user *s = buffer;
2045 if (!data || !table->maxlen || !*lenp ||
2046 (*ppos && !write)) {
2051 i = (unsigned long *) data;
2052 min = (unsigned long *) table->extra1;
2053 max = (unsigned long *) table->extra2;
2054 vleft = table->maxlen / sizeof(unsigned long);
2057 for (; left && vleft--; i++, min++, max++, first=0) {
2072 if (len > TMPBUFLEN-1)
2074 if (copy_from_user(buf, s, len))
2078 if (*p == '-' && left > 1) {
2082 if (*p < '0' || *p > '9')
2084 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2086 if ((len < left) && *p && !isspace(*p))
2095 if ((min && val < *min) || (max && val > *max))
2102 sprintf(p, "%lu", convdiv * (*i) / convmul);
2106 if(copy_to_user(s, buf, len))
2113 if (!write && !first && left) {
2114 if(put_user('\n', s))
2121 if (get_user(c, s++))
2136 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2138 void __user *buffer,
2139 size_t *lenp, loff_t *ppos,
2140 unsigned long convmul,
2141 unsigned long convdiv)
2143 return __do_proc_doulongvec_minmax(table->data, table, write,
2144 filp, buffer, lenp, ppos, convmul, convdiv);
2148 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2149 * @table: the sysctl table
2150 * @write: %TRUE if this is a write to the sysctl file
2151 * @filp: the file structure
2152 * @buffer: the user buffer
2153 * @lenp: the size of the user buffer
2154 * @ppos: file position
2156 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2157 * values from/to the user buffer, treated as an ASCII string.
2159 * This routine will ensure the values are within the range specified by
2160 * table->extra1 (min) and table->extra2 (max).
2162 * Returns 0 on success.
2164 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2165 void __user *buffer, size_t *lenp, loff_t *ppos)
2167 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2171 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2172 * @table: the sysctl table
2173 * @write: %TRUE if this is a write to the sysctl file
2174 * @filp: the file structure
2175 * @buffer: the user buffer
2176 * @lenp: the size of the user buffer
2177 * @ppos: file position
2179 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2180 * values from/to the user buffer, treated as an ASCII string. The values
2181 * are treated as milliseconds, and converted to jiffies when they are stored.
2183 * This routine will ensure the values are within the range specified by
2184 * table->extra1 (min) and table->extra2 (max).
2186 * Returns 0 on success.
2188 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2190 void __user *buffer,
2191 size_t *lenp, loff_t *ppos)
2193 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2194 lenp, ppos, HZ, 1000l);
2198 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2200 int write, void *data)
2203 if (*lvalp > LONG_MAX / HZ)
2205 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2211 lval = (unsigned long)-val;
2214 lval = (unsigned long)val;
2221 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2223 int write, void *data)
2226 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2228 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2234 lval = (unsigned long)-val;
2237 lval = (unsigned long)val;
2239 *lvalp = jiffies_to_clock_t(lval);
2244 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2246 int write, void *data)
2249 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2255 lval = (unsigned long)-val;
2258 lval = (unsigned long)val;
2260 *lvalp = jiffies_to_msecs(lval);
2266 * proc_dointvec_jiffies - read a vector of integers as seconds
2267 * @table: the sysctl table
2268 * @write: %TRUE if this is a write to the sysctl file
2269 * @filp: the file structure
2270 * @buffer: the user buffer
2271 * @lenp: the size of the user buffer
2272 * @ppos: file position
2274 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2275 * values from/to the user buffer, treated as an ASCII string.
2276 * The values read are assumed to be in seconds, and are converted into
2279 * Returns 0 on success.
2281 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2282 void __user *buffer, size_t *lenp, loff_t *ppos)
2284 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2285 do_proc_dointvec_jiffies_conv,NULL);
2289 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2290 * @table: the sysctl table
2291 * @write: %TRUE if this is a write to the sysctl file
2292 * @filp: the file structure
2293 * @buffer: the user buffer
2294 * @lenp: the size of the user buffer
2295 * @ppos: pointer to the file position
2297 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2298 * values from/to the user buffer, treated as an ASCII string.
2299 * The values read are assumed to be in 1/USER_HZ seconds, and
2300 * are converted into jiffies.
2302 * Returns 0 on success.
2304 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2305 void __user *buffer, size_t *lenp, loff_t *ppos)
2307 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2308 do_proc_dointvec_userhz_jiffies_conv,NULL);
2312 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2313 * @table: the sysctl table
2314 * @write: %TRUE if this is a write to the sysctl file
2315 * @filp: the file structure
2316 * @buffer: the user buffer
2317 * @lenp: the size of the user buffer
2318 * @ppos: file position
2319 * @ppos: the current position in the file
2321 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2322 * values from/to the user buffer, treated as an ASCII string.
2323 * The values read are assumed to be in 1/1000 seconds, and
2324 * are converted into jiffies.
2326 * Returns 0 on success.
2328 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2329 void __user *buffer, size_t *lenp, loff_t *ppos)
2331 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2332 do_proc_dointvec_ms_jiffies_conv, NULL);
2335 #ifdef CONFIG_SYSVIPC
2336 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
2337 void __user *buffer, size_t *lenp, loff_t *ppos)
2340 which = get_ipc(table, write);
2341 return __do_proc_dointvec(which, table, write, filp, buffer,
2342 lenp, ppos, NULL, NULL);
2345 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
2346 struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
2349 which = get_ipc(table, write);
2350 return __do_proc_doulongvec_minmax(which, table, write, filp, buffer,
2351 lenp, ppos, 1l, 1l);
2356 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2357 void __user *buffer, size_t *lenp, loff_t *ppos)
2359 struct pid *new_pid;
2363 tmp = pid_nr(cad_pid);
2365 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2366 lenp, ppos, NULL, NULL);
2370 new_pid = find_get_pid(tmp);
2374 put_pid(xchg(&cad_pid, new_pid));
2378 #else /* CONFIG_PROC_FS */
2380 int proc_dostring(ctl_table *table, int write, struct file *filp,
2381 void __user *buffer, size_t *lenp, loff_t *ppos)
2386 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
2387 void __user *buffer, size_t *lenp, loff_t *ppos)
2392 #ifdef CONFIG_SYSVIPC
2393 static int proc_do_ipc_string(ctl_table *table, int write, struct file *filp,
2394 void __user *buffer, size_t *lenp, loff_t *ppos)
2400 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2401 void __user *buffer, size_t *lenp, loff_t *ppos)
2406 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2407 void __user *buffer, size_t *lenp, loff_t *ppos)
2412 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2413 void __user *buffer, size_t *lenp, loff_t *ppos)
2418 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2419 void __user *buffer, size_t *lenp, loff_t *ppos)
2424 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2425 void __user *buffer, size_t *lenp, loff_t *ppos)
2430 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2431 void __user *buffer, size_t *lenp, loff_t *ppos)
2436 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2437 void __user *buffer, size_t *lenp, loff_t *ppos)
2442 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2444 void __user *buffer,
2445 size_t *lenp, loff_t *ppos)
2451 #endif /* CONFIG_PROC_FS */
2454 #ifdef CONFIG_SYSCTL_SYSCALL
2456 * General sysctl support routines
2459 /* The generic string strategy routine: */
2460 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2461 void __user *oldval, size_t __user *oldlenp,
2462 void __user *newval, size_t newlen, void **context)
2464 if (!table->data || !table->maxlen)
2467 if (oldval && oldlenp) {
2469 if (get_user(bufsize, oldlenp))
2472 size_t len = strlen(table->data), copied;
2474 /* This shouldn't trigger for a well-formed sysctl */
2475 if (len > table->maxlen)
2476 len = table->maxlen;
2478 /* Copy up to a max of bufsize-1 bytes of the string */
2479 copied = (len >= bufsize) ? bufsize - 1 : len;
2481 if (copy_to_user(oldval, table->data, copied) ||
2482 put_user(0, (char __user *)(oldval + copied)))
2484 if (put_user(len, oldlenp))
2488 if (newval && newlen) {
2489 size_t len = newlen;
2490 if (len > table->maxlen)
2491 len = table->maxlen;
2492 if(copy_from_user(table->data, newval, len))
2494 if (len == table->maxlen)
2496 ((char *) table->data)[len] = 0;
2502 * This function makes sure that all of the integers in the vector
2503 * are between the minimum and maximum values given in the arrays
2504 * table->extra1 and table->extra2, respectively.
2506 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2507 void __user *oldval, size_t __user *oldlenp,
2508 void __user *newval, size_t newlen, void **context)
2511 if (newval && newlen) {
2512 int __user *vec = (int __user *) newval;
2513 int *min = (int *) table->extra1;
2514 int *max = (int *) table->extra2;
2518 if (newlen % sizeof(int) != 0)
2521 if (!table->extra1 && !table->extra2)
2524 if (newlen > table->maxlen)
2525 newlen = table->maxlen;
2526 length = newlen / sizeof(int);
2528 for (i = 0; i < length; i++) {
2530 if (get_user(value, vec + i))
2532 if (min && value < min[i])
2534 if (max && value > max[i])
2541 /* Strategy function to convert jiffies to seconds */
2542 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2543 void __user *oldval, size_t __user *oldlenp,
2544 void __user *newval, size_t newlen, void **context)
2549 if (get_user(olen, oldlenp))
2551 if (olen!=sizeof(int))
2554 if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) ||
2555 (oldlenp && put_user(sizeof(int),oldlenp)))
2558 if (newval && newlen) {
2560 if (newlen != sizeof(int))
2562 if (get_user(new, (int __user *)newval))
2564 *(int *)(table->data) = new*HZ;
2569 /* Strategy function to convert jiffies to seconds */
2570 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2571 void __user *oldval, size_t __user *oldlenp,
2572 void __user *newval, size_t newlen, void **context)
2577 if (get_user(olen, oldlenp))
2579 if (olen!=sizeof(int))
2582 if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
2583 (oldlenp && put_user(sizeof(int),oldlenp)))
2586 if (newval && newlen) {
2588 if (newlen != sizeof(int))
2590 if (get_user(new, (int __user *)newval))
2592 *(int *)(table->data) = msecs_to_jiffies(new);
2598 /* The generic string strategy routine: */
2599 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
2600 void __user *oldval, size_t __user *oldlenp,
2601 void __user *newval, size_t newlen, void **context)
2603 struct ctl_table uts_table;
2605 write = newval && newlen;
2606 memcpy(&uts_table, table, sizeof(uts_table));
2607 uts_table.data = get_uts(table, write);
2608 r = sysctl_string(&uts_table, name, nlen,
2609 oldval, oldlenp, newval, newlen, context);
2610 put_uts(table, write, uts_table.data);
2614 #else /* CONFIG_SYSCTL_SYSCALL */
2617 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2619 static int msg_count;
2620 struct __sysctl_args tmp;
2621 int name[CTL_MAXNAME];
2624 /* Read in the sysctl name for better debug message logging */
2625 if (copy_from_user(&tmp, args, sizeof(tmp)))
2627 if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2629 for (i = 0; i < tmp.nlen; i++)
2630 if (get_user(name[i], tmp.name + i))
2633 /* Ignore accesses to kernel.version */
2634 if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2637 if (msg_count < 5) {
2640 "warning: process `%s' used the removed sysctl "
2641 "system call with ", current->comm);
2642 for (i = 0; i < tmp.nlen; i++)
2643 printk("%d.", name[i]);
2650 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2651 void __user *oldval, size_t __user *oldlenp,
2652 void __user *newval, size_t newlen, void **context)
2657 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2658 void __user *oldval, size_t __user *oldlenp,
2659 void __user *newval, size_t newlen, void **context)
2664 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2665 void __user *oldval, size_t __user *oldlenp,
2666 void __user *newval, size_t newlen, void **context)
2671 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2672 void __user *oldval, size_t __user *oldlenp,
2673 void __user *newval, size_t newlen, void **context)
2678 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
2679 void __user *oldval, size_t __user *oldlenp,
2680 void __user *newval, size_t newlen, void **context)
2684 #endif /* CONFIG_SYSCTL_SYSCALL */
2687 * No sense putting this after each symbol definition, twice,
2688 * exception granted :-)
2690 EXPORT_SYMBOL(proc_dointvec);
2691 EXPORT_SYMBOL(proc_dointvec_jiffies);
2692 EXPORT_SYMBOL(proc_dointvec_minmax);
2693 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2694 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2695 EXPORT_SYMBOL(proc_dostring);
2696 EXPORT_SYMBOL(proc_doulongvec_minmax);
2697 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2698 EXPORT_SYMBOL(register_sysctl_table);
2699 EXPORT_SYMBOL(sysctl_intvec);
2700 EXPORT_SYMBOL(sysctl_jiffies);
2701 EXPORT_SYMBOL(sysctl_ms_jiffies);
2702 EXPORT_SYMBOL(sysctl_string);
2703 EXPORT_SYMBOL(unregister_sysctl_table);