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>
22 #include <linux/aio.h>
24 #include <linux/swap.h>
25 #include <linux/slab.h>
26 #include <linux/sysctl.h>
27 #include <linux/bitmap.h>
28 #include <linux/signal.h>
29 #include <linux/printk.h>
30 #include <linux/proc_fs.h>
31 #include <linux/security.h>
32 #include <linux/ctype.h>
33 #include <linux/kmemcheck.h>
34 #include <linux/kmemleak.h>
36 #include <linux/init.h>
37 #include <linux/kernel.h>
38 #include <linux/kobject.h>
39 #include <linux/net.h>
40 #include <linux/sysrq.h>
41 #include <linux/highuid.h>
42 #include <linux/writeback.h>
43 #include <linux/ratelimit.h>
44 #include <linux/compaction.h>
45 #include <linux/hugetlb.h>
46 #include <linux/initrd.h>
47 #include <linux/key.h>
48 #include <linux/times.h>
49 #include <linux/limits.h>
50 #include <linux/dcache.h>
51 #include <linux/dnotify.h>
52 #include <linux/syscalls.h>
53 #include <linux/vmstat.h>
54 #include <linux/nfs_fs.h>
55 #include <linux/acpi.h>
56 #include <linux/reboot.h>
57 #include <linux/ftrace.h>
58 #include <linux/perf_event.h>
59 #include <linux/kprobes.h>
60 #include <linux/pipe_fs_i.h>
61 #include <linux/oom.h>
62 #include <linux/kmod.h>
63 #include <linux/capability.h>
64 #include <linux/binfmts.h>
65 #include <linux/sched/sysctl.h>
66 #include <linux/kexec.h>
67 #include <linux/bpf.h>
69 #include <asm/uaccess.h>
70 #include <asm/processor.h>
74 #include <asm/stacktrace.h>
78 #include <asm/setup.h>
80 #ifdef CONFIG_BSD_PROCESS_ACCT
81 #include <linux/acct.h>
83 #ifdef CONFIG_RT_MUTEXES
84 #include <linux/rtmutex.h>
86 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
87 #include <linux/lockdep.h>
89 #ifdef CONFIG_CHR_DEV_SG
93 #ifdef CONFIG_LOCKUP_DETECTOR
94 #include <linux/nmi.h>
97 #if defined(CONFIG_SYSCTL)
99 /* External variables not in a header file. */
100 extern int suid_dumpable;
101 #ifdef CONFIG_COREDUMP
102 extern int core_uses_pid;
103 extern char core_pattern[];
104 extern unsigned int core_pipe_limit;
107 extern int pid_max_min, pid_max_max;
108 extern int percpu_pagelist_fraction;
109 extern int compat_log;
110 extern int latencytop_enabled;
111 extern int sysctl_nr_open_min, sysctl_nr_open_max;
113 extern int sysctl_nr_trim_pages;
116 /* Constants used for minimum and maximum */
117 #ifdef CONFIG_LOCKUP_DETECTOR
118 static int sixty = 60;
121 static int __maybe_unused neg_one = -1;
124 static int __maybe_unused one = 1;
125 static int __maybe_unused two = 2;
126 static int __maybe_unused four = 4;
127 static unsigned long one_ul = 1;
128 static int one_hundred = 100;
129 static int one_thousand = 1000;
131 static int ten_thousand = 10000;
134 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
135 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
137 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
138 static int maxolduid = 65535;
139 static int minolduid;
141 static int ngroups_max = NGROUPS_MAX;
142 static const int cap_last_cap = CAP_LAST_CAP;
144 /*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */
145 #ifdef CONFIG_DETECT_HUNG_TASK
146 static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
149 #ifdef CONFIG_INOTIFY_USER
150 #include <linux/inotify.h>
156 extern int pwrsw_enabled;
159 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
160 extern int unaligned_enabled;
164 extern int unaligned_dump_stack;
167 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
168 extern int no_unaligned_warning;
171 #ifdef CONFIG_PROC_SYSCTL
173 #define SYSCTL_WRITES_LEGACY -1
174 #define SYSCTL_WRITES_WARN 0
175 #define SYSCTL_WRITES_STRICT 1
177 static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
179 static int proc_do_cad_pid(struct ctl_table *table, int write,
180 void __user *buffer, size_t *lenp, loff_t *ppos);
181 static int proc_taint(struct ctl_table *table, int write,
182 void __user *buffer, size_t *lenp, loff_t *ppos);
186 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
187 void __user *buffer, size_t *lenp, loff_t *ppos);
190 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
191 void __user *buffer, size_t *lenp, loff_t *ppos);
192 #ifdef CONFIG_COREDUMP
193 static int proc_dostring_coredump(struct ctl_table *table, int write,
194 void __user *buffer, size_t *lenp, loff_t *ppos);
197 #ifdef CONFIG_MAGIC_SYSRQ
198 /* Note: sysrq code uses it's own private copy */
199 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
201 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
202 void __user *buffer, size_t *lenp,
207 error = proc_dointvec(table, write, buffer, lenp, ppos);
212 sysrq_toggle_support(__sysrq_enabled);
219 static struct ctl_table kern_table[];
220 static struct ctl_table vm_table[];
221 static struct ctl_table fs_table[];
222 static struct ctl_table debug_table[];
223 static struct ctl_table dev_table[];
224 extern struct ctl_table random_table[];
226 extern struct ctl_table epoll_table[];
229 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
230 int sysctl_legacy_va_layout;
233 /* The default sysctl tables: */
235 static struct ctl_table sysctl_base_table[] = {
237 .procname = "kernel",
254 .child = debug_table,
264 #ifdef CONFIG_SCHED_DEBUG
265 static int min_sched_granularity_ns = 100000; /* 100 usecs */
266 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
267 static int min_wakeup_granularity_ns; /* 0 usecs */
268 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
270 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
271 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
272 #endif /* CONFIG_SMP */
273 #endif /* CONFIG_SCHED_DEBUG */
275 #ifdef CONFIG_COMPACTION
276 static int min_extfrag_threshold;
277 static int max_extfrag_threshold = 1000;
280 static struct ctl_table kern_table[] = {
282 .procname = "sched_child_runs_first",
283 .data = &sysctl_sched_child_runs_first,
284 .maxlen = sizeof(unsigned int),
286 .proc_handler = proc_dointvec,
288 #ifdef CONFIG_SCHED_DEBUG
290 .procname = "sched_min_granularity_ns",
291 .data = &sysctl_sched_min_granularity,
292 .maxlen = sizeof(unsigned int),
294 .proc_handler = sched_proc_update_handler,
295 .extra1 = &min_sched_granularity_ns,
296 .extra2 = &max_sched_granularity_ns,
299 .procname = "sched_latency_ns",
300 .data = &sysctl_sched_latency,
301 .maxlen = sizeof(unsigned int),
303 .proc_handler = sched_proc_update_handler,
304 .extra1 = &min_sched_granularity_ns,
305 .extra2 = &max_sched_granularity_ns,
308 .procname = "sched_wakeup_granularity_ns",
309 .data = &sysctl_sched_wakeup_granularity,
310 .maxlen = sizeof(unsigned int),
312 .proc_handler = sched_proc_update_handler,
313 .extra1 = &min_wakeup_granularity_ns,
314 .extra2 = &max_wakeup_granularity_ns,
318 .procname = "sched_tunable_scaling",
319 .data = &sysctl_sched_tunable_scaling,
320 .maxlen = sizeof(enum sched_tunable_scaling),
322 .proc_handler = sched_proc_update_handler,
323 .extra1 = &min_sched_tunable_scaling,
324 .extra2 = &max_sched_tunable_scaling,
327 .procname = "sched_migration_cost_ns",
328 .data = &sysctl_sched_migration_cost,
329 .maxlen = sizeof(unsigned int),
331 .proc_handler = proc_dointvec,
334 .procname = "sched_nr_migrate",
335 .data = &sysctl_sched_nr_migrate,
336 .maxlen = sizeof(unsigned int),
338 .proc_handler = proc_dointvec,
341 .procname = "sched_time_avg_ms",
342 .data = &sysctl_sched_time_avg,
343 .maxlen = sizeof(unsigned int),
345 .proc_handler = proc_dointvec,
348 .procname = "sched_shares_window_ns",
349 .data = &sysctl_sched_shares_window,
350 .maxlen = sizeof(unsigned int),
352 .proc_handler = proc_dointvec,
354 #ifdef CONFIG_SCHEDSTATS
356 .procname = "sched_schedstats",
358 .maxlen = sizeof(unsigned int),
360 .proc_handler = sysctl_schedstats,
364 #endif /* CONFIG_SCHEDSTATS */
365 #endif /* CONFIG_SMP */
366 #ifdef CONFIG_NUMA_BALANCING
368 .procname = "numa_balancing_scan_delay_ms",
369 .data = &sysctl_numa_balancing_scan_delay,
370 .maxlen = sizeof(unsigned int),
372 .proc_handler = proc_dointvec,
375 .procname = "numa_balancing_scan_period_min_ms",
376 .data = &sysctl_numa_balancing_scan_period_min,
377 .maxlen = sizeof(unsigned int),
379 .proc_handler = proc_dointvec,
382 .procname = "numa_balancing_scan_period_max_ms",
383 .data = &sysctl_numa_balancing_scan_period_max,
384 .maxlen = sizeof(unsigned int),
386 .proc_handler = proc_dointvec,
389 .procname = "numa_balancing_scan_size_mb",
390 .data = &sysctl_numa_balancing_scan_size,
391 .maxlen = sizeof(unsigned int),
393 .proc_handler = proc_dointvec_minmax,
397 .procname = "numa_balancing",
398 .data = NULL, /* filled in by handler */
399 .maxlen = sizeof(unsigned int),
401 .proc_handler = sysctl_numa_balancing,
405 #endif /* CONFIG_NUMA_BALANCING */
406 #endif /* CONFIG_SCHED_DEBUG */
408 .procname = "sched_rt_period_us",
409 .data = &sysctl_sched_rt_period,
410 .maxlen = sizeof(unsigned int),
412 .proc_handler = sched_rt_handler,
415 .procname = "sched_rt_runtime_us",
416 .data = &sysctl_sched_rt_runtime,
417 .maxlen = sizeof(int),
419 .proc_handler = sched_rt_handler,
422 .procname = "sched_rr_timeslice_ms",
423 .data = &sched_rr_timeslice,
424 .maxlen = sizeof(int),
426 .proc_handler = sched_rr_handler,
428 #ifdef CONFIG_SCHED_AUTOGROUP
430 .procname = "sched_autogroup_enabled",
431 .data = &sysctl_sched_autogroup_enabled,
432 .maxlen = sizeof(unsigned int),
434 .proc_handler = proc_dointvec_minmax,
439 #ifdef CONFIG_CFS_BANDWIDTH
441 .procname = "sched_cfs_bandwidth_slice_us",
442 .data = &sysctl_sched_cfs_bandwidth_slice,
443 .maxlen = sizeof(unsigned int),
445 .proc_handler = proc_dointvec_minmax,
449 #ifdef CONFIG_PROVE_LOCKING
451 .procname = "prove_locking",
452 .data = &prove_locking,
453 .maxlen = sizeof(int),
455 .proc_handler = proc_dointvec,
458 #ifdef CONFIG_LOCK_STAT
460 .procname = "lock_stat",
462 .maxlen = sizeof(int),
464 .proc_handler = proc_dointvec,
469 .data = &panic_timeout,
470 .maxlen = sizeof(int),
472 .proc_handler = proc_dointvec,
474 #ifdef CONFIG_COREDUMP
476 .procname = "core_uses_pid",
477 .data = &core_uses_pid,
478 .maxlen = sizeof(int),
480 .proc_handler = proc_dointvec,
483 .procname = "core_pattern",
484 .data = core_pattern,
485 .maxlen = CORENAME_MAX_SIZE,
487 .proc_handler = proc_dostring_coredump,
490 .procname = "core_pipe_limit",
491 .data = &core_pipe_limit,
492 .maxlen = sizeof(unsigned int),
494 .proc_handler = proc_dointvec,
497 #ifdef CONFIG_PROC_SYSCTL
499 .procname = "tainted",
500 .maxlen = sizeof(long),
502 .proc_handler = proc_taint,
505 .procname = "sysctl_writes_strict",
506 .data = &sysctl_writes_strict,
507 .maxlen = sizeof(int),
509 .proc_handler = proc_dointvec_minmax,
514 #ifdef CONFIG_LATENCYTOP
516 .procname = "latencytop",
517 .data = &latencytop_enabled,
518 .maxlen = sizeof(int),
520 .proc_handler = sysctl_latencytop,
523 #ifdef CONFIG_BLK_DEV_INITRD
525 .procname = "real-root-dev",
526 .data = &real_root_dev,
527 .maxlen = sizeof(int),
529 .proc_handler = proc_dointvec,
533 .procname = "print-fatal-signals",
534 .data = &print_fatal_signals,
535 .maxlen = sizeof(int),
537 .proc_handler = proc_dointvec,
541 .procname = "reboot-cmd",
542 .data = reboot_command,
545 .proc_handler = proc_dostring,
548 .procname = "stop-a",
549 .data = &stop_a_enabled,
550 .maxlen = sizeof (int),
552 .proc_handler = proc_dointvec,
555 .procname = "scons-poweroff",
556 .data = &scons_pwroff,
557 .maxlen = sizeof (int),
559 .proc_handler = proc_dointvec,
562 #ifdef CONFIG_SPARC64
564 .procname = "tsb-ratio",
565 .data = &sysctl_tsb_ratio,
566 .maxlen = sizeof (int),
568 .proc_handler = proc_dointvec,
573 .procname = "soft-power",
574 .data = &pwrsw_enabled,
575 .maxlen = sizeof (int),
577 .proc_handler = proc_dointvec,
580 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
582 .procname = "unaligned-trap",
583 .data = &unaligned_enabled,
584 .maxlen = sizeof (int),
586 .proc_handler = proc_dointvec,
590 .procname = "ctrl-alt-del",
592 .maxlen = sizeof(int),
594 .proc_handler = proc_dointvec,
596 #ifdef CONFIG_FUNCTION_TRACER
598 .procname = "ftrace_enabled",
599 .data = &ftrace_enabled,
600 .maxlen = sizeof(int),
602 .proc_handler = ftrace_enable_sysctl,
605 #ifdef CONFIG_STACK_TRACER
607 .procname = "stack_tracer_enabled",
608 .data = &stack_tracer_enabled,
609 .maxlen = sizeof(int),
611 .proc_handler = stack_trace_sysctl,
614 #ifdef CONFIG_TRACING
616 .procname = "ftrace_dump_on_oops",
617 .data = &ftrace_dump_on_oops,
618 .maxlen = sizeof(int),
620 .proc_handler = proc_dointvec,
623 .procname = "traceoff_on_warning",
624 .data = &__disable_trace_on_warning,
625 .maxlen = sizeof(__disable_trace_on_warning),
627 .proc_handler = proc_dointvec,
630 .procname = "tracepoint_printk",
631 .data = &tracepoint_printk,
632 .maxlen = sizeof(tracepoint_printk),
634 .proc_handler = proc_dointvec,
637 #ifdef CONFIG_KEXEC_CORE
639 .procname = "kexec_load_disabled",
640 .data = &kexec_load_disabled,
641 .maxlen = sizeof(int),
643 /* only handle a transition from default "0" to "1" */
644 .proc_handler = proc_dointvec_minmax,
649 #ifdef CONFIG_MODULES
651 .procname = "modprobe",
652 .data = &modprobe_path,
653 .maxlen = KMOD_PATH_LEN,
655 .proc_handler = proc_dostring,
658 .procname = "modules_disabled",
659 .data = &modules_disabled,
660 .maxlen = sizeof(int),
662 /* only handle a transition from default "0" to "1" */
663 .proc_handler = proc_dointvec_minmax,
668 #ifdef CONFIG_UEVENT_HELPER
670 .procname = "hotplug",
671 .data = &uevent_helper,
672 .maxlen = UEVENT_HELPER_PATH_LEN,
674 .proc_handler = proc_dostring,
677 #ifdef CONFIG_CHR_DEV_SG
679 .procname = "sg-big-buff",
680 .data = &sg_big_buff,
681 .maxlen = sizeof (int),
683 .proc_handler = proc_dointvec,
686 #ifdef CONFIG_BSD_PROCESS_ACCT
690 .maxlen = 3*sizeof(int),
692 .proc_handler = proc_dointvec,
695 #ifdef CONFIG_MAGIC_SYSRQ
698 .data = &__sysrq_enabled,
699 .maxlen = sizeof (int),
701 .proc_handler = sysrq_sysctl_handler,
704 #ifdef CONFIG_PROC_SYSCTL
706 .procname = "cad_pid",
708 .maxlen = sizeof (int),
710 .proc_handler = proc_do_cad_pid,
714 .procname = "threads-max",
716 .maxlen = sizeof(int),
718 .proc_handler = sysctl_max_threads,
721 .procname = "random",
723 .child = random_table,
726 .procname = "usermodehelper",
728 .child = usermodehelper_table,
731 .procname = "overflowuid",
732 .data = &overflowuid,
733 .maxlen = sizeof(int),
735 .proc_handler = proc_dointvec_minmax,
736 .extra1 = &minolduid,
737 .extra2 = &maxolduid,
740 .procname = "overflowgid",
741 .data = &overflowgid,
742 .maxlen = sizeof(int),
744 .proc_handler = proc_dointvec_minmax,
745 .extra1 = &minolduid,
746 .extra2 = &maxolduid,
749 #ifdef CONFIG_MATHEMU
751 .procname = "ieee_emulation_warnings",
752 .data = &sysctl_ieee_emulation_warnings,
753 .maxlen = sizeof(int),
755 .proc_handler = proc_dointvec,
759 .procname = "userprocess_debug",
760 .data = &show_unhandled_signals,
761 .maxlen = sizeof(int),
763 .proc_handler = proc_dointvec,
767 .procname = "pid_max",
769 .maxlen = sizeof (int),
771 .proc_handler = proc_dointvec_minmax,
772 .extra1 = &pid_max_min,
773 .extra2 = &pid_max_max,
776 .procname = "panic_on_oops",
777 .data = &panic_on_oops,
778 .maxlen = sizeof(int),
780 .proc_handler = proc_dointvec,
782 #if defined CONFIG_PRINTK
784 .procname = "printk",
785 .data = &console_loglevel,
786 .maxlen = 4*sizeof(int),
788 .proc_handler = proc_dointvec,
791 .procname = "printk_ratelimit",
792 .data = &printk_ratelimit_state.interval,
793 .maxlen = sizeof(int),
795 .proc_handler = proc_dointvec_jiffies,
798 .procname = "printk_ratelimit_burst",
799 .data = &printk_ratelimit_state.burst,
800 .maxlen = sizeof(int),
802 .proc_handler = proc_dointvec,
805 .procname = "printk_delay",
806 .data = &printk_delay_msec,
807 .maxlen = sizeof(int),
809 .proc_handler = proc_dointvec_minmax,
811 .extra2 = &ten_thousand,
814 .procname = "dmesg_restrict",
815 .data = &dmesg_restrict,
816 .maxlen = sizeof(int),
818 .proc_handler = proc_dointvec_minmax_sysadmin,
823 .procname = "kptr_restrict",
824 .data = &kptr_restrict,
825 .maxlen = sizeof(int),
827 .proc_handler = proc_dointvec_minmax_sysadmin,
833 .procname = "ngroups_max",
834 .data = &ngroups_max,
835 .maxlen = sizeof (int),
837 .proc_handler = proc_dointvec,
840 .procname = "cap_last_cap",
841 .data = (void *)&cap_last_cap,
842 .maxlen = sizeof(int),
844 .proc_handler = proc_dointvec,
846 #if defined(CONFIG_LOCKUP_DETECTOR)
848 .procname = "watchdog",
849 .data = &watchdog_user_enabled,
850 .maxlen = sizeof (int),
852 .proc_handler = proc_watchdog,
857 .procname = "watchdog_thresh",
858 .data = &watchdog_thresh,
859 .maxlen = sizeof(int),
861 .proc_handler = proc_watchdog_thresh,
866 .procname = "nmi_watchdog",
867 .data = &nmi_watchdog_enabled,
868 .maxlen = sizeof (int),
870 .proc_handler = proc_nmi_watchdog,
872 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
879 .procname = "soft_watchdog",
880 .data = &soft_watchdog_enabled,
881 .maxlen = sizeof (int),
883 .proc_handler = proc_soft_watchdog,
888 .procname = "watchdog_cpumask",
889 .data = &watchdog_cpumask_bits,
892 .proc_handler = proc_watchdog_cpumask,
895 .procname = "softlockup_panic",
896 .data = &softlockup_panic,
897 .maxlen = sizeof(int),
899 .proc_handler = proc_dointvec_minmax,
903 #ifdef CONFIG_HARDLOCKUP_DETECTOR
905 .procname = "hardlockup_panic",
906 .data = &hardlockup_panic,
907 .maxlen = sizeof(int),
909 .proc_handler = proc_dointvec_minmax,
916 .procname = "softlockup_all_cpu_backtrace",
917 .data = &sysctl_softlockup_all_cpu_backtrace,
918 .maxlen = sizeof(int),
920 .proc_handler = proc_dointvec_minmax,
925 .procname = "hardlockup_all_cpu_backtrace",
926 .data = &sysctl_hardlockup_all_cpu_backtrace,
927 .maxlen = sizeof(int),
929 .proc_handler = proc_dointvec_minmax,
933 #endif /* CONFIG_SMP */
935 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
937 .procname = "unknown_nmi_panic",
938 .data = &unknown_nmi_panic,
939 .maxlen = sizeof (int),
941 .proc_handler = proc_dointvec,
944 #if defined(CONFIG_X86)
946 .procname = "panic_on_unrecovered_nmi",
947 .data = &panic_on_unrecovered_nmi,
948 .maxlen = sizeof(int),
950 .proc_handler = proc_dointvec,
953 .procname = "panic_on_io_nmi",
954 .data = &panic_on_io_nmi,
955 .maxlen = sizeof(int),
957 .proc_handler = proc_dointvec,
959 #ifdef CONFIG_DEBUG_STACKOVERFLOW
961 .procname = "panic_on_stackoverflow",
962 .data = &sysctl_panic_on_stackoverflow,
963 .maxlen = sizeof(int),
965 .proc_handler = proc_dointvec,
969 .procname = "bootloader_type",
970 .data = &bootloader_type,
971 .maxlen = sizeof (int),
973 .proc_handler = proc_dointvec,
976 .procname = "bootloader_version",
977 .data = &bootloader_version,
978 .maxlen = sizeof (int),
980 .proc_handler = proc_dointvec,
983 .procname = "kstack_depth_to_print",
984 .data = &kstack_depth_to_print,
985 .maxlen = sizeof(int),
987 .proc_handler = proc_dointvec,
990 .procname = "io_delay_type",
991 .data = &io_delay_type,
992 .maxlen = sizeof(int),
994 .proc_handler = proc_dointvec,
997 #if defined(CONFIG_MMU)
999 .procname = "randomize_va_space",
1000 .data = &randomize_va_space,
1001 .maxlen = sizeof(int),
1003 .proc_handler = proc_dointvec,
1006 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1008 .procname = "spin_retry",
1009 .data = &spin_retry,
1010 .maxlen = sizeof (int),
1012 .proc_handler = proc_dointvec,
1015 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1017 .procname = "acpi_video_flags",
1018 .data = &acpi_realmode_flags,
1019 .maxlen = sizeof (unsigned long),
1021 .proc_handler = proc_doulongvec_minmax,
1024 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1026 .procname = "ignore-unaligned-usertrap",
1027 .data = &no_unaligned_warning,
1028 .maxlen = sizeof (int),
1030 .proc_handler = proc_dointvec,
1035 .procname = "unaligned-dump-stack",
1036 .data = &unaligned_dump_stack,
1037 .maxlen = sizeof (int),
1039 .proc_handler = proc_dointvec,
1042 #ifdef CONFIG_DETECT_HUNG_TASK
1044 .procname = "hung_task_panic",
1045 .data = &sysctl_hung_task_panic,
1046 .maxlen = sizeof(int),
1048 .proc_handler = proc_dointvec_minmax,
1053 .procname = "hung_task_check_count",
1054 .data = &sysctl_hung_task_check_count,
1055 .maxlen = sizeof(int),
1057 .proc_handler = proc_dointvec_minmax,
1061 .procname = "hung_task_timeout_secs",
1062 .data = &sysctl_hung_task_timeout_secs,
1063 .maxlen = sizeof(unsigned long),
1065 .proc_handler = proc_dohung_task_timeout_secs,
1066 .extra2 = &hung_task_timeout_max,
1069 .procname = "hung_task_warnings",
1070 .data = &sysctl_hung_task_warnings,
1071 .maxlen = sizeof(int),
1073 .proc_handler = proc_dointvec_minmax,
1077 #ifdef CONFIG_COMPAT
1079 .procname = "compat-log",
1080 .data = &compat_log,
1081 .maxlen = sizeof (int),
1083 .proc_handler = proc_dointvec,
1086 #ifdef CONFIG_RT_MUTEXES
1088 .procname = "max_lock_depth",
1089 .data = &max_lock_depth,
1090 .maxlen = sizeof(int),
1092 .proc_handler = proc_dointvec,
1096 .procname = "poweroff_cmd",
1097 .data = &poweroff_cmd,
1098 .maxlen = POWEROFF_CMD_PATH_LEN,
1100 .proc_handler = proc_dostring,
1106 .child = key_sysctls,
1109 #ifdef CONFIG_PERF_EVENTS
1111 * User-space scripts rely on the existence of this file
1112 * as a feature check for perf_events being enabled.
1114 * So it's an ABI, do not remove!
1117 .procname = "perf_event_paranoid",
1118 .data = &sysctl_perf_event_paranoid,
1119 .maxlen = sizeof(sysctl_perf_event_paranoid),
1121 .proc_handler = proc_dointvec,
1124 .procname = "perf_event_mlock_kb",
1125 .data = &sysctl_perf_event_mlock,
1126 .maxlen = sizeof(sysctl_perf_event_mlock),
1128 .proc_handler = proc_dointvec,
1131 .procname = "perf_event_max_sample_rate",
1132 .data = &sysctl_perf_event_sample_rate,
1133 .maxlen = sizeof(sysctl_perf_event_sample_rate),
1135 .proc_handler = perf_proc_update_handler,
1139 .procname = "perf_cpu_time_max_percent",
1140 .data = &sysctl_perf_cpu_time_max_percent,
1141 .maxlen = sizeof(sysctl_perf_cpu_time_max_percent),
1143 .proc_handler = perf_cpu_time_max_percent_handler,
1145 .extra2 = &one_hundred,
1148 #ifdef CONFIG_KMEMCHECK
1150 .procname = "kmemcheck",
1151 .data = &kmemcheck_enabled,
1152 .maxlen = sizeof(int),
1154 .proc_handler = proc_dointvec,
1158 .procname = "panic_on_warn",
1159 .data = &panic_on_warn,
1160 .maxlen = sizeof(int),
1162 .proc_handler = proc_dointvec_minmax,
1166 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1168 .procname = "timer_migration",
1169 .data = &sysctl_timer_migration,
1170 .maxlen = sizeof(unsigned int),
1172 .proc_handler = timer_migration_handler,
1175 #ifdef CONFIG_BPF_SYSCALL
1177 .procname = "unprivileged_bpf_disabled",
1178 .data = &sysctl_unprivileged_bpf_disabled,
1179 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
1181 /* only handle a transition from default "0" to "1" */
1182 .proc_handler = proc_dointvec_minmax,
1190 static struct ctl_table vm_table[] = {
1192 .procname = "overcommit_memory",
1193 .data = &sysctl_overcommit_memory,
1194 .maxlen = sizeof(sysctl_overcommit_memory),
1196 .proc_handler = proc_dointvec_minmax,
1201 .procname = "panic_on_oom",
1202 .data = &sysctl_panic_on_oom,
1203 .maxlen = sizeof(sysctl_panic_on_oom),
1205 .proc_handler = proc_dointvec_minmax,
1210 .procname = "oom_kill_allocating_task",
1211 .data = &sysctl_oom_kill_allocating_task,
1212 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1214 .proc_handler = proc_dointvec,
1217 .procname = "oom_dump_tasks",
1218 .data = &sysctl_oom_dump_tasks,
1219 .maxlen = sizeof(sysctl_oom_dump_tasks),
1221 .proc_handler = proc_dointvec,
1224 .procname = "overcommit_ratio",
1225 .data = &sysctl_overcommit_ratio,
1226 .maxlen = sizeof(sysctl_overcommit_ratio),
1228 .proc_handler = overcommit_ratio_handler,
1231 .procname = "overcommit_kbytes",
1232 .data = &sysctl_overcommit_kbytes,
1233 .maxlen = sizeof(sysctl_overcommit_kbytes),
1235 .proc_handler = overcommit_kbytes_handler,
1238 .procname = "page-cluster",
1239 .data = &page_cluster,
1240 .maxlen = sizeof(int),
1242 .proc_handler = proc_dointvec_minmax,
1246 .procname = "dirty_background_ratio",
1247 .data = &dirty_background_ratio,
1248 .maxlen = sizeof(dirty_background_ratio),
1250 .proc_handler = dirty_background_ratio_handler,
1252 .extra2 = &one_hundred,
1255 .procname = "dirty_background_bytes",
1256 .data = &dirty_background_bytes,
1257 .maxlen = sizeof(dirty_background_bytes),
1259 .proc_handler = dirty_background_bytes_handler,
1263 .procname = "dirty_ratio",
1264 .data = &vm_dirty_ratio,
1265 .maxlen = sizeof(vm_dirty_ratio),
1267 .proc_handler = dirty_ratio_handler,
1269 .extra2 = &one_hundred,
1272 .procname = "dirty_bytes",
1273 .data = &vm_dirty_bytes,
1274 .maxlen = sizeof(vm_dirty_bytes),
1276 .proc_handler = dirty_bytes_handler,
1277 .extra1 = &dirty_bytes_min,
1280 .procname = "dirty_writeback_centisecs",
1281 .data = &dirty_writeback_interval,
1282 .maxlen = sizeof(dirty_writeback_interval),
1284 .proc_handler = dirty_writeback_centisecs_handler,
1287 .procname = "dirty_expire_centisecs",
1288 .data = &dirty_expire_interval,
1289 .maxlen = sizeof(dirty_expire_interval),
1291 .proc_handler = proc_dointvec_minmax,
1295 .procname = "dirtytime_expire_seconds",
1296 .data = &dirtytime_expire_interval,
1297 .maxlen = sizeof(dirty_expire_interval),
1299 .proc_handler = dirtytime_interval_handler,
1303 .procname = "nr_pdflush_threads",
1304 .mode = 0444 /* read-only */,
1305 .proc_handler = pdflush_proc_obsolete,
1308 .procname = "swappiness",
1309 .data = &vm_swappiness,
1310 .maxlen = sizeof(vm_swappiness),
1312 .proc_handler = proc_dointvec_minmax,
1314 .extra2 = &one_hundred,
1316 #ifdef CONFIG_HUGETLB_PAGE
1318 .procname = "nr_hugepages",
1320 .maxlen = sizeof(unsigned long),
1322 .proc_handler = hugetlb_sysctl_handler,
1326 .procname = "nr_hugepages_mempolicy",
1328 .maxlen = sizeof(unsigned long),
1330 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1334 .procname = "hugetlb_shm_group",
1335 .data = &sysctl_hugetlb_shm_group,
1336 .maxlen = sizeof(gid_t),
1338 .proc_handler = proc_dointvec,
1341 .procname = "hugepages_treat_as_movable",
1342 .data = &hugepages_treat_as_movable,
1343 .maxlen = sizeof(int),
1345 .proc_handler = proc_dointvec,
1348 .procname = "nr_overcommit_hugepages",
1350 .maxlen = sizeof(unsigned long),
1352 .proc_handler = hugetlb_overcommit_handler,
1356 .procname = "lowmem_reserve_ratio",
1357 .data = &sysctl_lowmem_reserve_ratio,
1358 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1360 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1363 .procname = "drop_caches",
1364 .data = &sysctl_drop_caches,
1365 .maxlen = sizeof(int),
1367 .proc_handler = drop_caches_sysctl_handler,
1371 #ifdef CONFIG_COMPACTION
1373 .procname = "compact_memory",
1374 .data = &sysctl_compact_memory,
1375 .maxlen = sizeof(int),
1377 .proc_handler = sysctl_compaction_handler,
1380 .procname = "extfrag_threshold",
1381 .data = &sysctl_extfrag_threshold,
1382 .maxlen = sizeof(int),
1384 .proc_handler = sysctl_extfrag_handler,
1385 .extra1 = &min_extfrag_threshold,
1386 .extra2 = &max_extfrag_threshold,
1389 .procname = "compact_unevictable_allowed",
1390 .data = &sysctl_compact_unevictable_allowed,
1391 .maxlen = sizeof(int),
1393 .proc_handler = proc_dointvec,
1398 #endif /* CONFIG_COMPACTION */
1400 .procname = "min_free_kbytes",
1401 .data = &min_free_kbytes,
1402 .maxlen = sizeof(min_free_kbytes),
1404 .proc_handler = min_free_kbytes_sysctl_handler,
1408 .procname = "watermark_scale_factor",
1409 .data = &watermark_scale_factor,
1410 .maxlen = sizeof(watermark_scale_factor),
1412 .proc_handler = watermark_scale_factor_sysctl_handler,
1414 .extra2 = &one_thousand,
1417 .procname = "percpu_pagelist_fraction",
1418 .data = &percpu_pagelist_fraction,
1419 .maxlen = sizeof(percpu_pagelist_fraction),
1421 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1426 .procname = "max_map_count",
1427 .data = &sysctl_max_map_count,
1428 .maxlen = sizeof(sysctl_max_map_count),
1430 .proc_handler = proc_dointvec_minmax,
1435 .procname = "nr_trim_pages",
1436 .data = &sysctl_nr_trim_pages,
1437 .maxlen = sizeof(sysctl_nr_trim_pages),
1439 .proc_handler = proc_dointvec_minmax,
1444 .procname = "laptop_mode",
1445 .data = &laptop_mode,
1446 .maxlen = sizeof(laptop_mode),
1448 .proc_handler = proc_dointvec_jiffies,
1451 .procname = "block_dump",
1452 .data = &block_dump,
1453 .maxlen = sizeof(block_dump),
1455 .proc_handler = proc_dointvec,
1459 .procname = "vfs_cache_pressure",
1460 .data = &sysctl_vfs_cache_pressure,
1461 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1463 .proc_handler = proc_dointvec,
1466 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1468 .procname = "legacy_va_layout",
1469 .data = &sysctl_legacy_va_layout,
1470 .maxlen = sizeof(sysctl_legacy_va_layout),
1472 .proc_handler = proc_dointvec,
1478 .procname = "zone_reclaim_mode",
1479 .data = &zone_reclaim_mode,
1480 .maxlen = sizeof(zone_reclaim_mode),
1482 .proc_handler = proc_dointvec,
1486 .procname = "min_unmapped_ratio",
1487 .data = &sysctl_min_unmapped_ratio,
1488 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1490 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1492 .extra2 = &one_hundred,
1495 .procname = "min_slab_ratio",
1496 .data = &sysctl_min_slab_ratio,
1497 .maxlen = sizeof(sysctl_min_slab_ratio),
1499 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1501 .extra2 = &one_hundred,
1506 .procname = "stat_interval",
1507 .data = &sysctl_stat_interval,
1508 .maxlen = sizeof(sysctl_stat_interval),
1510 .proc_handler = proc_dointvec_jiffies,
1515 .procname = "mmap_min_addr",
1516 .data = &dac_mmap_min_addr,
1517 .maxlen = sizeof(unsigned long),
1519 .proc_handler = mmap_min_addr_handler,
1524 .procname = "numa_zonelist_order",
1525 .data = &numa_zonelist_order,
1526 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1528 .proc_handler = numa_zonelist_order_handler,
1531 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1532 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1534 .procname = "vdso_enabled",
1535 #ifdef CONFIG_X86_32
1536 .data = &vdso32_enabled,
1537 .maxlen = sizeof(vdso32_enabled),
1539 .data = &vdso_enabled,
1540 .maxlen = sizeof(vdso_enabled),
1543 .proc_handler = proc_dointvec,
1547 #ifdef CONFIG_HIGHMEM
1549 .procname = "highmem_is_dirtyable",
1550 .data = &vm_highmem_is_dirtyable,
1551 .maxlen = sizeof(vm_highmem_is_dirtyable),
1553 .proc_handler = proc_dointvec_minmax,
1558 #ifdef CONFIG_MEMORY_FAILURE
1560 .procname = "memory_failure_early_kill",
1561 .data = &sysctl_memory_failure_early_kill,
1562 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1564 .proc_handler = proc_dointvec_minmax,
1569 .procname = "memory_failure_recovery",
1570 .data = &sysctl_memory_failure_recovery,
1571 .maxlen = sizeof(sysctl_memory_failure_recovery),
1573 .proc_handler = proc_dointvec_minmax,
1579 .procname = "user_reserve_kbytes",
1580 .data = &sysctl_user_reserve_kbytes,
1581 .maxlen = sizeof(sysctl_user_reserve_kbytes),
1583 .proc_handler = proc_doulongvec_minmax,
1586 .procname = "admin_reserve_kbytes",
1587 .data = &sysctl_admin_reserve_kbytes,
1588 .maxlen = sizeof(sysctl_admin_reserve_kbytes),
1590 .proc_handler = proc_doulongvec_minmax,
1592 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1594 .procname = "mmap_rnd_bits",
1595 .data = &mmap_rnd_bits,
1596 .maxlen = sizeof(mmap_rnd_bits),
1598 .proc_handler = proc_dointvec_minmax,
1599 .extra1 = (void *)&mmap_rnd_bits_min,
1600 .extra2 = (void *)&mmap_rnd_bits_max,
1603 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1605 .procname = "mmap_rnd_compat_bits",
1606 .data = &mmap_rnd_compat_bits,
1607 .maxlen = sizeof(mmap_rnd_compat_bits),
1609 .proc_handler = proc_dointvec_minmax,
1610 .extra1 = (void *)&mmap_rnd_compat_bits_min,
1611 .extra2 = (void *)&mmap_rnd_compat_bits_max,
1617 static struct ctl_table fs_table[] = {
1619 .procname = "inode-nr",
1620 .data = &inodes_stat,
1621 .maxlen = 2*sizeof(long),
1623 .proc_handler = proc_nr_inodes,
1626 .procname = "inode-state",
1627 .data = &inodes_stat,
1628 .maxlen = 7*sizeof(long),
1630 .proc_handler = proc_nr_inodes,
1633 .procname = "file-nr",
1634 .data = &files_stat,
1635 .maxlen = sizeof(files_stat),
1637 .proc_handler = proc_nr_files,
1640 .procname = "file-max",
1641 .data = &files_stat.max_files,
1642 .maxlen = sizeof(files_stat.max_files),
1644 .proc_handler = proc_doulongvec_minmax,
1647 .procname = "nr_open",
1648 .data = &sysctl_nr_open,
1649 .maxlen = sizeof(int),
1651 .proc_handler = proc_dointvec_minmax,
1652 .extra1 = &sysctl_nr_open_min,
1653 .extra2 = &sysctl_nr_open_max,
1656 .procname = "dentry-state",
1657 .data = &dentry_stat,
1658 .maxlen = 6*sizeof(long),
1660 .proc_handler = proc_nr_dentry,
1663 .procname = "overflowuid",
1664 .data = &fs_overflowuid,
1665 .maxlen = sizeof(int),
1667 .proc_handler = proc_dointvec_minmax,
1668 .extra1 = &minolduid,
1669 .extra2 = &maxolduid,
1672 .procname = "overflowgid",
1673 .data = &fs_overflowgid,
1674 .maxlen = sizeof(int),
1676 .proc_handler = proc_dointvec_minmax,
1677 .extra1 = &minolduid,
1678 .extra2 = &maxolduid,
1680 #ifdef CONFIG_FILE_LOCKING
1682 .procname = "leases-enable",
1683 .data = &leases_enable,
1684 .maxlen = sizeof(int),
1686 .proc_handler = proc_dointvec,
1689 #ifdef CONFIG_DNOTIFY
1691 .procname = "dir-notify-enable",
1692 .data = &dir_notify_enable,
1693 .maxlen = sizeof(int),
1695 .proc_handler = proc_dointvec,
1699 #ifdef CONFIG_FILE_LOCKING
1701 .procname = "lease-break-time",
1702 .data = &lease_break_time,
1703 .maxlen = sizeof(int),
1705 .proc_handler = proc_dointvec,
1710 .procname = "aio-nr",
1712 .maxlen = sizeof(aio_nr),
1714 .proc_handler = proc_doulongvec_minmax,
1717 .procname = "aio-max-nr",
1718 .data = &aio_max_nr,
1719 .maxlen = sizeof(aio_max_nr),
1721 .proc_handler = proc_doulongvec_minmax,
1723 #endif /* CONFIG_AIO */
1724 #ifdef CONFIG_INOTIFY_USER
1726 .procname = "inotify",
1728 .child = inotify_table,
1733 .procname = "epoll",
1735 .child = epoll_table,
1740 .procname = "protected_symlinks",
1741 .data = &sysctl_protected_symlinks,
1742 .maxlen = sizeof(int),
1744 .proc_handler = proc_dointvec_minmax,
1749 .procname = "protected_hardlinks",
1750 .data = &sysctl_protected_hardlinks,
1751 .maxlen = sizeof(int),
1753 .proc_handler = proc_dointvec_minmax,
1758 .procname = "suid_dumpable",
1759 .data = &suid_dumpable,
1760 .maxlen = sizeof(int),
1762 .proc_handler = proc_dointvec_minmax_coredump,
1766 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1768 .procname = "binfmt_misc",
1770 .child = sysctl_mount_point,
1774 .procname = "pipe-max-size",
1775 .data = &pipe_max_size,
1776 .maxlen = sizeof(int),
1778 .proc_handler = &pipe_proc_fn,
1779 .extra1 = &pipe_min_size,
1782 .procname = "pipe-user-pages-hard",
1783 .data = &pipe_user_pages_hard,
1784 .maxlen = sizeof(pipe_user_pages_hard),
1786 .proc_handler = proc_doulongvec_minmax,
1789 .procname = "pipe-user-pages-soft",
1790 .data = &pipe_user_pages_soft,
1791 .maxlen = sizeof(pipe_user_pages_soft),
1793 .proc_handler = proc_doulongvec_minmax,
1798 static struct ctl_table debug_table[] = {
1799 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1801 .procname = "exception-trace",
1802 .data = &show_unhandled_signals,
1803 .maxlen = sizeof(int),
1805 .proc_handler = proc_dointvec
1808 #if defined(CONFIG_OPTPROBES)
1810 .procname = "kprobes-optimization",
1811 .data = &sysctl_kprobes_optimization,
1812 .maxlen = sizeof(int),
1814 .proc_handler = proc_kprobes_optimization_handler,
1822 static struct ctl_table dev_table[] = {
1826 int __init sysctl_init(void)
1828 struct ctl_table_header *hdr;
1830 hdr = register_sysctl_table(sysctl_base_table);
1831 kmemleak_not_leak(hdr);
1835 #endif /* CONFIG_SYSCTL */
1841 #ifdef CONFIG_PROC_SYSCTL
1843 static int _proc_do_string(char *data, int maxlen, int write,
1844 char __user *buffer,
1845 size_t *lenp, loff_t *ppos)
1851 if (!data || !maxlen || !*lenp) {
1857 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1858 /* Only continue writes not past the end of buffer. */
1860 if (len > maxlen - 1)
1867 /* Start writing from beginning of buffer. */
1873 while ((p - buffer) < *lenp && len < maxlen - 1) {
1874 if (get_user(c, p++))
1876 if (c == 0 || c == '\n')
1897 if (copy_to_user(buffer, data, len))
1900 if (put_user('\n', buffer + len))
1910 static void warn_sysctl_write(struct ctl_table *table)
1912 pr_warn_once("%s wrote to %s when file position was not 0!\n"
1913 "This will not be supported in the future. To silence this\n"
1914 "warning, set kernel.sysctl_writes_strict = -1\n",
1915 current->comm, table->procname);
1919 * proc_dostring - read a string sysctl
1920 * @table: the sysctl table
1921 * @write: %TRUE if this is a write to the sysctl file
1922 * @buffer: the user buffer
1923 * @lenp: the size of the user buffer
1924 * @ppos: file position
1926 * Reads/writes a string from/to the user buffer. If the kernel
1927 * buffer provided is not large enough to hold the string, the
1928 * string is truncated. The copied string is %NULL-terminated.
1929 * If the string is being read by the user process, it is copied
1930 * and a newline '\n' is added. It is truncated if the buffer is
1933 * Returns 0 on success.
1935 int proc_dostring(struct ctl_table *table, int write,
1936 void __user *buffer, size_t *lenp, loff_t *ppos)
1938 if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1939 warn_sysctl_write(table);
1941 return _proc_do_string((char *)(table->data), table->maxlen, write,
1942 (char __user *)buffer, lenp, ppos);
1945 static size_t proc_skip_spaces(char **buf)
1948 char *tmp = skip_spaces(*buf);
1954 static void proc_skip_char(char **buf, size_t *size, const char v)
1964 #define TMPBUFLEN 22
1966 * proc_get_long - reads an ASCII formatted integer from a user buffer
1968 * @buf: a kernel buffer
1969 * @size: size of the kernel buffer
1970 * @val: this is where the number will be stored
1971 * @neg: set to %TRUE if number is negative
1972 * @perm_tr: a vector which contains the allowed trailers
1973 * @perm_tr_len: size of the perm_tr vector
1974 * @tr: pointer to store the trailer character
1976 * In case of success %0 is returned and @buf and @size are updated with
1977 * the amount of bytes read. If @tr is non-NULL and a trailing
1978 * character exists (size is non-zero after returning from this
1979 * function), @tr is updated with the trailing character.
1981 static int proc_get_long(char **buf, size_t *size,
1982 unsigned long *val, bool *neg,
1983 const char *perm_tr, unsigned perm_tr_len, char *tr)
1986 char *p, tmp[TMPBUFLEN];
1992 if (len > TMPBUFLEN - 1)
1993 len = TMPBUFLEN - 1;
1995 memcpy(tmp, *buf, len);
1999 if (*p == '-' && *size > 1) {
2007 *val = simple_strtoul(p, &p, 0);
2011 /* We don't know if the next char is whitespace thus we may accept
2012 * invalid integers (e.g. 1234...a) or two integers instead of one
2013 * (e.g. 123...1). So lets not allow such large numbers. */
2014 if (len == TMPBUFLEN - 1)
2017 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2020 if (tr && (len < *size))
2030 * proc_put_long - converts an integer to a decimal ASCII formatted string
2032 * @buf: the user buffer
2033 * @size: the size of the user buffer
2034 * @val: the integer to be converted
2035 * @neg: sign of the number, %TRUE for negative
2037 * In case of success %0 is returned and @buf and @size are updated with
2038 * the amount of bytes written.
2040 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2044 char tmp[TMPBUFLEN], *p = tmp;
2046 sprintf(p, "%s%lu", neg ? "-" : "", val);
2050 if (copy_to_user(*buf, tmp, len))
2058 static int proc_put_char(void __user **buf, size_t *size, char c)
2061 char __user **buffer = (char __user **)buf;
2062 if (put_user(c, *buffer))
2064 (*size)--, (*buffer)++;
2070 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2072 int write, void *data)
2076 if (*lvalp > (unsigned long) INT_MAX + 1)
2080 if (*lvalp > (unsigned long) INT_MAX)
2088 *lvalp = -(unsigned long)val;
2091 *lvalp = (unsigned long)val;
2097 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2099 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2100 int write, void __user *buffer,
2101 size_t *lenp, loff_t *ppos,
2102 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2103 int write, void *data),
2106 int *i, vleft, first = 1, err = 0;
2108 char *kbuf = NULL, *p;
2110 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2115 i = (int *) tbl_data;
2116 vleft = table->maxlen / sizeof(*i);
2120 conv = do_proc_dointvec_conv;
2124 switch (sysctl_writes_strict) {
2125 case SYSCTL_WRITES_STRICT:
2127 case SYSCTL_WRITES_WARN:
2128 warn_sysctl_write(table);
2135 if (left > PAGE_SIZE - 1)
2136 left = PAGE_SIZE - 1;
2137 p = kbuf = memdup_user_nul(buffer, left);
2139 return PTR_ERR(kbuf);
2142 for (; left && vleft--; i++, first=0) {
2147 left -= proc_skip_spaces(&p);
2151 err = proc_get_long(&p, &left, &lval, &neg,
2153 sizeof(proc_wspace_sep), NULL);
2156 if (conv(&neg, &lval, i, 1, data)) {
2161 if (conv(&neg, &lval, i, 0, data)) {
2166 err = proc_put_char(&buffer, &left, '\t');
2169 err = proc_put_long(&buffer, &left, lval, neg);
2175 if (!write && !first && left && !err)
2176 err = proc_put_char(&buffer, &left, '\n');
2177 if (write && !err && left)
2178 left -= proc_skip_spaces(&p);
2182 return err ? : -EINVAL;
2190 static int do_proc_dointvec(struct ctl_table *table, int write,
2191 void __user *buffer, size_t *lenp, loff_t *ppos,
2192 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2193 int write, void *data),
2196 return __do_proc_dointvec(table->data, table, write,
2197 buffer, lenp, ppos, conv, data);
2201 * proc_dointvec - read a vector of integers
2202 * @table: the sysctl table
2203 * @write: %TRUE if this is a write to the sysctl file
2204 * @buffer: the user buffer
2205 * @lenp: the size of the user buffer
2206 * @ppos: file position
2208 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2209 * values from/to the user buffer, treated as an ASCII string.
2211 * Returns 0 on success.
2213 int proc_dointvec(struct ctl_table *table, int write,
2214 void __user *buffer, size_t *lenp, loff_t *ppos)
2216 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2221 * Taint values can only be increased
2222 * This means we can safely use a temporary.
2224 static int proc_taint(struct ctl_table *table, int write,
2225 void __user *buffer, size_t *lenp, loff_t *ppos)
2228 unsigned long tmptaint = get_taint();
2231 if (write && !capable(CAP_SYS_ADMIN))
2236 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2242 * Poor man's atomic or. Not worth adding a primitive
2243 * to everyone's atomic.h for this
2246 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2247 if ((tmptaint >> i) & 1)
2248 add_taint(i, LOCKDEP_STILL_OK);
2255 #ifdef CONFIG_PRINTK
2256 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2257 void __user *buffer, size_t *lenp, loff_t *ppos)
2259 if (write && !capable(CAP_SYS_ADMIN))
2262 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2266 struct do_proc_dointvec_minmax_conv_param {
2271 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2273 int write, void *data)
2275 struct do_proc_dointvec_minmax_conv_param *param = data;
2277 int val = *negp ? -*lvalp : *lvalp;
2278 if ((param->min && *param->min > val) ||
2279 (param->max && *param->max < val))
2286 *lvalp = -(unsigned long)val;
2289 *lvalp = (unsigned long)val;
2296 * proc_dointvec_minmax - read a vector of integers with min/max values
2297 * @table: the sysctl table
2298 * @write: %TRUE if this is a write to the sysctl file
2299 * @buffer: the user buffer
2300 * @lenp: the size of the user buffer
2301 * @ppos: file position
2303 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2304 * values from/to the user buffer, treated as an ASCII string.
2306 * This routine will ensure the values are within the range specified by
2307 * table->extra1 (min) and table->extra2 (max).
2309 * Returns 0 on success.
2311 int proc_dointvec_minmax(struct ctl_table *table, int write,
2312 void __user *buffer, size_t *lenp, loff_t *ppos)
2314 struct do_proc_dointvec_minmax_conv_param param = {
2315 .min = (int *) table->extra1,
2316 .max = (int *) table->extra2,
2318 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2319 do_proc_dointvec_minmax_conv, ¶m);
2322 static void validate_coredump_safety(void)
2324 #ifdef CONFIG_COREDUMP
2325 if (suid_dumpable == SUID_DUMP_ROOT &&
2326 core_pattern[0] != '/' && core_pattern[0] != '|') {
2327 printk(KERN_WARNING "Unsafe core_pattern used with "\
2328 "suid_dumpable=2. Pipe handler or fully qualified "\
2329 "core dump path required.\n");
2334 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2335 void __user *buffer, size_t *lenp, loff_t *ppos)
2337 int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2339 validate_coredump_safety();
2343 #ifdef CONFIG_COREDUMP
2344 static int proc_dostring_coredump(struct ctl_table *table, int write,
2345 void __user *buffer, size_t *lenp, loff_t *ppos)
2347 int error = proc_dostring(table, write, buffer, lenp, ppos);
2349 validate_coredump_safety();
2354 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2355 void __user *buffer,
2356 size_t *lenp, loff_t *ppos,
2357 unsigned long convmul,
2358 unsigned long convdiv)
2360 unsigned long *i, *min, *max;
2361 int vleft, first = 1, err = 0;
2363 char *kbuf = NULL, *p;
2365 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2370 i = (unsigned long *) data;
2371 min = (unsigned long *) table->extra1;
2372 max = (unsigned long *) table->extra2;
2373 vleft = table->maxlen / sizeof(unsigned long);
2378 switch (sysctl_writes_strict) {
2379 case SYSCTL_WRITES_STRICT:
2381 case SYSCTL_WRITES_WARN:
2382 warn_sysctl_write(table);
2389 if (left > PAGE_SIZE - 1)
2390 left = PAGE_SIZE - 1;
2391 p = kbuf = memdup_user_nul(buffer, left);
2393 return PTR_ERR(kbuf);
2396 for (; left && vleft--; i++, first = 0) {
2402 left -= proc_skip_spaces(&p);
2404 err = proc_get_long(&p, &left, &val, &neg,
2406 sizeof(proc_wspace_sep), NULL);
2411 if ((min && val < *min) || (max && val > *max))
2415 val = convdiv * (*i) / convmul;
2417 err = proc_put_char(&buffer, &left, '\t');
2421 err = proc_put_long(&buffer, &left, val, false);
2427 if (!write && !first && left && !err)
2428 err = proc_put_char(&buffer, &left, '\n');
2430 left -= proc_skip_spaces(&p);
2434 return err ? : -EINVAL;
2442 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2443 void __user *buffer,
2444 size_t *lenp, loff_t *ppos,
2445 unsigned long convmul,
2446 unsigned long convdiv)
2448 return __do_proc_doulongvec_minmax(table->data, table, write,
2449 buffer, lenp, ppos, convmul, convdiv);
2453 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2454 * @table: the sysctl table
2455 * @write: %TRUE if this is a write to the sysctl file
2456 * @buffer: the user buffer
2457 * @lenp: the size of the user buffer
2458 * @ppos: file position
2460 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2461 * values from/to the user buffer, treated as an ASCII string.
2463 * This routine will ensure the values are within the range specified by
2464 * table->extra1 (min) and table->extra2 (max).
2466 * Returns 0 on success.
2468 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2469 void __user *buffer, size_t *lenp, loff_t *ppos)
2471 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2475 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2476 * @table: the sysctl table
2477 * @write: %TRUE if this is a write to the sysctl file
2478 * @buffer: the user buffer
2479 * @lenp: the size of the user buffer
2480 * @ppos: file position
2482 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2483 * values from/to the user buffer, treated as an ASCII string. The values
2484 * are treated as milliseconds, and converted to jiffies when they are stored.
2486 * This routine will ensure the values are within the range specified by
2487 * table->extra1 (min) and table->extra2 (max).
2489 * Returns 0 on success.
2491 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2492 void __user *buffer,
2493 size_t *lenp, loff_t *ppos)
2495 return do_proc_doulongvec_minmax(table, write, buffer,
2496 lenp, ppos, HZ, 1000l);
2500 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2502 int write, void *data)
2505 if (*lvalp > LONG_MAX / HZ)
2507 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2513 lval = -(unsigned long)val;
2516 lval = (unsigned long)val;
2523 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2525 int write, void *data)
2528 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2530 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2536 lval = -(unsigned long)val;
2539 lval = (unsigned long)val;
2541 *lvalp = jiffies_to_clock_t(lval);
2546 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2548 int write, void *data)
2551 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2561 lval = -(unsigned long)val;
2564 lval = (unsigned long)val;
2566 *lvalp = jiffies_to_msecs(lval);
2572 * proc_dointvec_jiffies - read a vector of integers as seconds
2573 * @table: the sysctl table
2574 * @write: %TRUE if this is a write to the sysctl file
2575 * @buffer: the user buffer
2576 * @lenp: the size of the user buffer
2577 * @ppos: file position
2579 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2580 * values from/to the user buffer, treated as an ASCII string.
2581 * The values read are assumed to be in seconds, and are converted into
2584 * Returns 0 on success.
2586 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2587 void __user *buffer, size_t *lenp, loff_t *ppos)
2589 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2590 do_proc_dointvec_jiffies_conv,NULL);
2594 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2595 * @table: the sysctl table
2596 * @write: %TRUE if this is a write to the sysctl file
2597 * @buffer: the user buffer
2598 * @lenp: the size of the user buffer
2599 * @ppos: pointer to the file position
2601 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2602 * values from/to the user buffer, treated as an ASCII string.
2603 * The values read are assumed to be in 1/USER_HZ seconds, and
2604 * are converted into jiffies.
2606 * Returns 0 on success.
2608 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2609 void __user *buffer, size_t *lenp, loff_t *ppos)
2611 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2612 do_proc_dointvec_userhz_jiffies_conv,NULL);
2616 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2617 * @table: the sysctl table
2618 * @write: %TRUE if this is a write to the sysctl file
2619 * @buffer: the user buffer
2620 * @lenp: the size of the user buffer
2621 * @ppos: file position
2622 * @ppos: the current position in the file
2624 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2625 * values from/to the user buffer, treated as an ASCII string.
2626 * The values read are assumed to be in 1/1000 seconds, and
2627 * are converted into jiffies.
2629 * Returns 0 on success.
2631 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2632 void __user *buffer, size_t *lenp, loff_t *ppos)
2634 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2635 do_proc_dointvec_ms_jiffies_conv, NULL);
2638 static int proc_do_cad_pid(struct ctl_table *table, int write,
2639 void __user *buffer, size_t *lenp, loff_t *ppos)
2641 struct pid *new_pid;
2645 tmp = pid_vnr(cad_pid);
2647 r = __do_proc_dointvec(&tmp, table, write, buffer,
2648 lenp, ppos, NULL, NULL);
2652 new_pid = find_get_pid(tmp);
2656 put_pid(xchg(&cad_pid, new_pid));
2661 * proc_do_large_bitmap - read/write from/to a large bitmap
2662 * @table: the sysctl table
2663 * @write: %TRUE if this is a write to the sysctl file
2664 * @buffer: the user buffer
2665 * @lenp: the size of the user buffer
2666 * @ppos: file position
2668 * The bitmap is stored at table->data and the bitmap length (in bits)
2671 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2672 * large bitmaps may be represented in a compact manner. Writing into
2673 * the file will clear the bitmap then update it with the given input.
2675 * Returns 0 on success.
2677 int proc_do_large_bitmap(struct ctl_table *table, int write,
2678 void __user *buffer, size_t *lenp, loff_t *ppos)
2682 size_t left = *lenp;
2683 unsigned long bitmap_len = table->maxlen;
2684 unsigned long *bitmap = *(unsigned long **) table->data;
2685 unsigned long *tmp_bitmap = NULL;
2686 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2688 if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2696 if (left > PAGE_SIZE - 1)
2697 left = PAGE_SIZE - 1;
2699 p = kbuf = memdup_user_nul(buffer, left);
2701 return PTR_ERR(kbuf);
2703 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2709 proc_skip_char(&p, &left, '\n');
2710 while (!err && left) {
2711 unsigned long val_a, val_b;
2714 err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2718 if (val_a >= bitmap_len || neg) {
2730 err = proc_get_long(&p, &left, &val_b,
2731 &neg, tr_b, sizeof(tr_b),
2735 if (val_b >= bitmap_len || neg ||
2746 bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2748 proc_skip_char(&p, &left, '\n');
2752 unsigned long bit_a, bit_b = 0;
2755 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2756 if (bit_a >= bitmap_len)
2758 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2762 err = proc_put_char(&buffer, &left, ',');
2766 err = proc_put_long(&buffer, &left, bit_a, false);
2769 if (bit_a != bit_b) {
2770 err = proc_put_char(&buffer, &left, '-');
2773 err = proc_put_long(&buffer, &left, bit_b, false);
2781 err = proc_put_char(&buffer, &left, '\n');
2787 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2789 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2801 #else /* CONFIG_PROC_SYSCTL */
2803 int proc_dostring(struct ctl_table *table, int write,
2804 void __user *buffer, size_t *lenp, loff_t *ppos)
2809 int proc_dointvec(struct ctl_table *table, int write,
2810 void __user *buffer, size_t *lenp, loff_t *ppos)
2815 int proc_dointvec_minmax(struct ctl_table *table, int write,
2816 void __user *buffer, size_t *lenp, loff_t *ppos)
2821 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2822 void __user *buffer, size_t *lenp, loff_t *ppos)
2827 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2828 void __user *buffer, size_t *lenp, loff_t *ppos)
2833 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2834 void __user *buffer, size_t *lenp, loff_t *ppos)
2839 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2840 void __user *buffer, size_t *lenp, loff_t *ppos)
2845 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2846 void __user *buffer,
2847 size_t *lenp, loff_t *ppos)
2853 #endif /* CONFIG_PROC_SYSCTL */
2856 * No sense putting this after each symbol definition, twice,
2857 * exception granted :-)
2859 EXPORT_SYMBOL(proc_dointvec);
2860 EXPORT_SYMBOL(proc_dointvec_jiffies);
2861 EXPORT_SYMBOL(proc_dointvec_minmax);
2862 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2863 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2864 EXPORT_SYMBOL(proc_dostring);
2865 EXPORT_SYMBOL(proc_doulongvec_minmax);
2866 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);