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;
133 #ifdef CONFIG_PERF_EVENTS
134 static int six_hundred_forty_kb = 640 * 1024;
137 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
138 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
140 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
141 static int maxolduid = 65535;
142 static int minolduid;
144 static int ngroups_max = NGROUPS_MAX;
145 static const int cap_last_cap = CAP_LAST_CAP;
147 /*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */
148 #ifdef CONFIG_DETECT_HUNG_TASK
149 static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
152 #ifdef CONFIG_INOTIFY_USER
153 #include <linux/inotify.h>
159 extern int pwrsw_enabled;
162 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
163 extern int unaligned_enabled;
167 extern int unaligned_dump_stack;
170 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
171 extern int no_unaligned_warning;
174 #ifdef CONFIG_PROC_SYSCTL
176 #define SYSCTL_WRITES_LEGACY -1
177 #define SYSCTL_WRITES_WARN 0
178 #define SYSCTL_WRITES_STRICT 1
180 static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
182 static int proc_do_cad_pid(struct ctl_table *table, int write,
183 void __user *buffer, size_t *lenp, loff_t *ppos);
184 static int proc_taint(struct ctl_table *table, int write,
185 void __user *buffer, size_t *lenp, loff_t *ppos);
189 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
190 void __user *buffer, size_t *lenp, loff_t *ppos);
193 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
194 void __user *buffer, size_t *lenp, loff_t *ppos);
195 #ifdef CONFIG_COREDUMP
196 static int proc_dostring_coredump(struct ctl_table *table, int write,
197 void __user *buffer, size_t *lenp, loff_t *ppos);
200 #ifdef CONFIG_MAGIC_SYSRQ
201 /* Note: sysrq code uses it's own private copy */
202 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
204 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
205 void __user *buffer, size_t *lenp,
210 error = proc_dointvec(table, write, buffer, lenp, ppos);
215 sysrq_toggle_support(__sysrq_enabled);
222 static struct ctl_table kern_table[];
223 static struct ctl_table vm_table[];
224 static struct ctl_table fs_table[];
225 static struct ctl_table debug_table[];
226 static struct ctl_table dev_table[];
227 extern struct ctl_table random_table[];
229 extern struct ctl_table epoll_table[];
232 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
233 int sysctl_legacy_va_layout;
236 /* The default sysctl tables: */
238 static struct ctl_table sysctl_base_table[] = {
240 .procname = "kernel",
257 .child = debug_table,
267 #ifdef CONFIG_SCHED_DEBUG
268 static int min_sched_granularity_ns = 100000; /* 100 usecs */
269 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
270 static int min_wakeup_granularity_ns; /* 0 usecs */
271 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
273 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
274 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
275 #endif /* CONFIG_SMP */
276 #endif /* CONFIG_SCHED_DEBUG */
278 #ifdef CONFIG_COMPACTION
279 static int min_extfrag_threshold;
280 static int max_extfrag_threshold = 1000;
283 static struct ctl_table kern_table[] = {
285 .procname = "sched_child_runs_first",
286 .data = &sysctl_sched_child_runs_first,
287 .maxlen = sizeof(unsigned int),
289 .proc_handler = proc_dointvec,
291 #ifdef CONFIG_SCHED_DEBUG
293 .procname = "sched_min_granularity_ns",
294 .data = &sysctl_sched_min_granularity,
295 .maxlen = sizeof(unsigned int),
297 .proc_handler = sched_proc_update_handler,
298 .extra1 = &min_sched_granularity_ns,
299 .extra2 = &max_sched_granularity_ns,
302 .procname = "sched_latency_ns",
303 .data = &sysctl_sched_latency,
304 .maxlen = sizeof(unsigned int),
306 .proc_handler = sched_proc_update_handler,
307 .extra1 = &min_sched_granularity_ns,
308 .extra2 = &max_sched_granularity_ns,
311 .procname = "sched_wakeup_granularity_ns",
312 .data = &sysctl_sched_wakeup_granularity,
313 .maxlen = sizeof(unsigned int),
315 .proc_handler = sched_proc_update_handler,
316 .extra1 = &min_wakeup_granularity_ns,
317 .extra2 = &max_wakeup_granularity_ns,
321 .procname = "sched_tunable_scaling",
322 .data = &sysctl_sched_tunable_scaling,
323 .maxlen = sizeof(enum sched_tunable_scaling),
325 .proc_handler = sched_proc_update_handler,
326 .extra1 = &min_sched_tunable_scaling,
327 .extra2 = &max_sched_tunable_scaling,
330 .procname = "sched_migration_cost_ns",
331 .data = &sysctl_sched_migration_cost,
332 .maxlen = sizeof(unsigned int),
334 .proc_handler = proc_dointvec,
337 .procname = "sched_nr_migrate",
338 .data = &sysctl_sched_nr_migrate,
339 .maxlen = sizeof(unsigned int),
341 .proc_handler = proc_dointvec,
344 .procname = "sched_time_avg_ms",
345 .data = &sysctl_sched_time_avg,
346 .maxlen = sizeof(unsigned int),
348 .proc_handler = proc_dointvec,
351 .procname = "sched_shares_window_ns",
352 .data = &sysctl_sched_shares_window,
353 .maxlen = sizeof(unsigned int),
355 .proc_handler = proc_dointvec,
357 #ifdef CONFIG_SCHEDSTATS
359 .procname = "sched_schedstats",
361 .maxlen = sizeof(unsigned int),
363 .proc_handler = sysctl_schedstats,
367 #endif /* CONFIG_SCHEDSTATS */
368 #endif /* CONFIG_SMP */
369 #ifdef CONFIG_NUMA_BALANCING
371 .procname = "numa_balancing_scan_delay_ms",
372 .data = &sysctl_numa_balancing_scan_delay,
373 .maxlen = sizeof(unsigned int),
375 .proc_handler = proc_dointvec,
378 .procname = "numa_balancing_scan_period_min_ms",
379 .data = &sysctl_numa_balancing_scan_period_min,
380 .maxlen = sizeof(unsigned int),
382 .proc_handler = proc_dointvec,
385 .procname = "numa_balancing_scan_period_max_ms",
386 .data = &sysctl_numa_balancing_scan_period_max,
387 .maxlen = sizeof(unsigned int),
389 .proc_handler = proc_dointvec,
392 .procname = "numa_balancing_scan_size_mb",
393 .data = &sysctl_numa_balancing_scan_size,
394 .maxlen = sizeof(unsigned int),
396 .proc_handler = proc_dointvec_minmax,
400 .procname = "numa_balancing",
401 .data = NULL, /* filled in by handler */
402 .maxlen = sizeof(unsigned int),
404 .proc_handler = sysctl_numa_balancing,
408 #endif /* CONFIG_NUMA_BALANCING */
409 #endif /* CONFIG_SCHED_DEBUG */
411 .procname = "sched_rt_period_us",
412 .data = &sysctl_sched_rt_period,
413 .maxlen = sizeof(unsigned int),
415 .proc_handler = sched_rt_handler,
418 .procname = "sched_rt_runtime_us",
419 .data = &sysctl_sched_rt_runtime,
420 .maxlen = sizeof(int),
422 .proc_handler = sched_rt_handler,
425 .procname = "sched_rr_timeslice_ms",
426 .data = &sched_rr_timeslice,
427 .maxlen = sizeof(int),
429 .proc_handler = sched_rr_handler,
431 #ifdef CONFIG_SCHED_AUTOGROUP
433 .procname = "sched_autogroup_enabled",
434 .data = &sysctl_sched_autogroup_enabled,
435 .maxlen = sizeof(unsigned int),
437 .proc_handler = proc_dointvec_minmax,
442 #ifdef CONFIG_CFS_BANDWIDTH
444 .procname = "sched_cfs_bandwidth_slice_us",
445 .data = &sysctl_sched_cfs_bandwidth_slice,
446 .maxlen = sizeof(unsigned int),
448 .proc_handler = proc_dointvec_minmax,
452 #ifdef CONFIG_PROVE_LOCKING
454 .procname = "prove_locking",
455 .data = &prove_locking,
456 .maxlen = sizeof(int),
458 .proc_handler = proc_dointvec,
461 #ifdef CONFIG_LOCK_STAT
463 .procname = "lock_stat",
465 .maxlen = sizeof(int),
467 .proc_handler = proc_dointvec,
472 .data = &panic_timeout,
473 .maxlen = sizeof(int),
475 .proc_handler = proc_dointvec,
477 #ifdef CONFIG_COREDUMP
479 .procname = "core_uses_pid",
480 .data = &core_uses_pid,
481 .maxlen = sizeof(int),
483 .proc_handler = proc_dointvec,
486 .procname = "core_pattern",
487 .data = core_pattern,
488 .maxlen = CORENAME_MAX_SIZE,
490 .proc_handler = proc_dostring_coredump,
493 .procname = "core_pipe_limit",
494 .data = &core_pipe_limit,
495 .maxlen = sizeof(unsigned int),
497 .proc_handler = proc_dointvec,
500 #ifdef CONFIG_PROC_SYSCTL
502 .procname = "tainted",
503 .maxlen = sizeof(long),
505 .proc_handler = proc_taint,
508 .procname = "sysctl_writes_strict",
509 .data = &sysctl_writes_strict,
510 .maxlen = sizeof(int),
512 .proc_handler = proc_dointvec_minmax,
517 #ifdef CONFIG_LATENCYTOP
519 .procname = "latencytop",
520 .data = &latencytop_enabled,
521 .maxlen = sizeof(int),
523 .proc_handler = sysctl_latencytop,
526 #ifdef CONFIG_BLK_DEV_INITRD
528 .procname = "real-root-dev",
529 .data = &real_root_dev,
530 .maxlen = sizeof(int),
532 .proc_handler = proc_dointvec,
536 .procname = "print-fatal-signals",
537 .data = &print_fatal_signals,
538 .maxlen = sizeof(int),
540 .proc_handler = proc_dointvec,
544 .procname = "reboot-cmd",
545 .data = reboot_command,
548 .proc_handler = proc_dostring,
551 .procname = "stop-a",
552 .data = &stop_a_enabled,
553 .maxlen = sizeof (int),
555 .proc_handler = proc_dointvec,
558 .procname = "scons-poweroff",
559 .data = &scons_pwroff,
560 .maxlen = sizeof (int),
562 .proc_handler = proc_dointvec,
565 #ifdef CONFIG_SPARC64
567 .procname = "tsb-ratio",
568 .data = &sysctl_tsb_ratio,
569 .maxlen = sizeof (int),
571 .proc_handler = proc_dointvec,
576 .procname = "soft-power",
577 .data = &pwrsw_enabled,
578 .maxlen = sizeof (int),
580 .proc_handler = proc_dointvec,
583 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
585 .procname = "unaligned-trap",
586 .data = &unaligned_enabled,
587 .maxlen = sizeof (int),
589 .proc_handler = proc_dointvec,
593 .procname = "ctrl-alt-del",
595 .maxlen = sizeof(int),
597 .proc_handler = proc_dointvec,
599 #ifdef CONFIG_FUNCTION_TRACER
601 .procname = "ftrace_enabled",
602 .data = &ftrace_enabled,
603 .maxlen = sizeof(int),
605 .proc_handler = ftrace_enable_sysctl,
608 #ifdef CONFIG_STACK_TRACER
610 .procname = "stack_tracer_enabled",
611 .data = &stack_tracer_enabled,
612 .maxlen = sizeof(int),
614 .proc_handler = stack_trace_sysctl,
617 #ifdef CONFIG_TRACING
619 .procname = "ftrace_dump_on_oops",
620 .data = &ftrace_dump_on_oops,
621 .maxlen = sizeof(int),
623 .proc_handler = proc_dointvec,
626 .procname = "traceoff_on_warning",
627 .data = &__disable_trace_on_warning,
628 .maxlen = sizeof(__disable_trace_on_warning),
630 .proc_handler = proc_dointvec,
633 .procname = "tracepoint_printk",
634 .data = &tracepoint_printk,
635 .maxlen = sizeof(tracepoint_printk),
637 .proc_handler = proc_dointvec,
640 #ifdef CONFIG_KEXEC_CORE
642 .procname = "kexec_load_disabled",
643 .data = &kexec_load_disabled,
644 .maxlen = sizeof(int),
646 /* only handle a transition from default "0" to "1" */
647 .proc_handler = proc_dointvec_minmax,
652 #ifdef CONFIG_MODULES
654 .procname = "modprobe",
655 .data = &modprobe_path,
656 .maxlen = KMOD_PATH_LEN,
658 .proc_handler = proc_dostring,
661 .procname = "modules_disabled",
662 .data = &modules_disabled,
663 .maxlen = sizeof(int),
665 /* only handle a transition from default "0" to "1" */
666 .proc_handler = proc_dointvec_minmax,
671 #ifdef CONFIG_UEVENT_HELPER
673 .procname = "hotplug",
674 .data = &uevent_helper,
675 .maxlen = UEVENT_HELPER_PATH_LEN,
677 .proc_handler = proc_dostring,
680 #ifdef CONFIG_CHR_DEV_SG
682 .procname = "sg-big-buff",
683 .data = &sg_big_buff,
684 .maxlen = sizeof (int),
686 .proc_handler = proc_dointvec,
689 #ifdef CONFIG_BSD_PROCESS_ACCT
693 .maxlen = 3*sizeof(int),
695 .proc_handler = proc_dointvec,
698 #ifdef CONFIG_MAGIC_SYSRQ
701 .data = &__sysrq_enabled,
702 .maxlen = sizeof (int),
704 .proc_handler = sysrq_sysctl_handler,
707 #ifdef CONFIG_PROC_SYSCTL
709 .procname = "cad_pid",
711 .maxlen = sizeof (int),
713 .proc_handler = proc_do_cad_pid,
717 .procname = "threads-max",
719 .maxlen = sizeof(int),
721 .proc_handler = sysctl_max_threads,
724 .procname = "random",
726 .child = random_table,
729 .procname = "usermodehelper",
731 .child = usermodehelper_table,
734 .procname = "overflowuid",
735 .data = &overflowuid,
736 .maxlen = sizeof(int),
738 .proc_handler = proc_dointvec_minmax,
739 .extra1 = &minolduid,
740 .extra2 = &maxolduid,
743 .procname = "overflowgid",
744 .data = &overflowgid,
745 .maxlen = sizeof(int),
747 .proc_handler = proc_dointvec_minmax,
748 .extra1 = &minolduid,
749 .extra2 = &maxolduid,
752 #ifdef CONFIG_MATHEMU
754 .procname = "ieee_emulation_warnings",
755 .data = &sysctl_ieee_emulation_warnings,
756 .maxlen = sizeof(int),
758 .proc_handler = proc_dointvec,
762 .procname = "userprocess_debug",
763 .data = &show_unhandled_signals,
764 .maxlen = sizeof(int),
766 .proc_handler = proc_dointvec,
770 .procname = "pid_max",
772 .maxlen = sizeof (int),
774 .proc_handler = proc_dointvec_minmax,
775 .extra1 = &pid_max_min,
776 .extra2 = &pid_max_max,
779 .procname = "panic_on_oops",
780 .data = &panic_on_oops,
781 .maxlen = sizeof(int),
783 .proc_handler = proc_dointvec,
785 #if defined CONFIG_PRINTK
787 .procname = "printk",
788 .data = &console_loglevel,
789 .maxlen = 4*sizeof(int),
791 .proc_handler = proc_dointvec,
794 .procname = "printk_ratelimit",
795 .data = &printk_ratelimit_state.interval,
796 .maxlen = sizeof(int),
798 .proc_handler = proc_dointvec_jiffies,
801 .procname = "printk_ratelimit_burst",
802 .data = &printk_ratelimit_state.burst,
803 .maxlen = sizeof(int),
805 .proc_handler = proc_dointvec,
808 .procname = "printk_delay",
809 .data = &printk_delay_msec,
810 .maxlen = sizeof(int),
812 .proc_handler = proc_dointvec_minmax,
814 .extra2 = &ten_thousand,
817 .procname = "dmesg_restrict",
818 .data = &dmesg_restrict,
819 .maxlen = sizeof(int),
821 .proc_handler = proc_dointvec_minmax_sysadmin,
826 .procname = "kptr_restrict",
827 .data = &kptr_restrict,
828 .maxlen = sizeof(int),
830 .proc_handler = proc_dointvec_minmax_sysadmin,
836 .procname = "ngroups_max",
837 .data = &ngroups_max,
838 .maxlen = sizeof (int),
840 .proc_handler = proc_dointvec,
843 .procname = "cap_last_cap",
844 .data = (void *)&cap_last_cap,
845 .maxlen = sizeof(int),
847 .proc_handler = proc_dointvec,
849 #if defined(CONFIG_LOCKUP_DETECTOR)
851 .procname = "watchdog",
852 .data = &watchdog_user_enabled,
853 .maxlen = sizeof (int),
855 .proc_handler = proc_watchdog,
860 .procname = "watchdog_thresh",
861 .data = &watchdog_thresh,
862 .maxlen = sizeof(int),
864 .proc_handler = proc_watchdog_thresh,
869 .procname = "nmi_watchdog",
870 .data = &nmi_watchdog_enabled,
871 .maxlen = sizeof (int),
873 .proc_handler = proc_nmi_watchdog,
875 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
882 .procname = "soft_watchdog",
883 .data = &soft_watchdog_enabled,
884 .maxlen = sizeof (int),
886 .proc_handler = proc_soft_watchdog,
891 .procname = "watchdog_cpumask",
892 .data = &watchdog_cpumask_bits,
895 .proc_handler = proc_watchdog_cpumask,
898 .procname = "softlockup_panic",
899 .data = &softlockup_panic,
900 .maxlen = sizeof(int),
902 .proc_handler = proc_dointvec_minmax,
906 #ifdef CONFIG_HARDLOCKUP_DETECTOR
908 .procname = "hardlockup_panic",
909 .data = &hardlockup_panic,
910 .maxlen = sizeof(int),
912 .proc_handler = proc_dointvec_minmax,
919 .procname = "softlockup_all_cpu_backtrace",
920 .data = &sysctl_softlockup_all_cpu_backtrace,
921 .maxlen = sizeof(int),
923 .proc_handler = proc_dointvec_minmax,
928 .procname = "hardlockup_all_cpu_backtrace",
929 .data = &sysctl_hardlockup_all_cpu_backtrace,
930 .maxlen = sizeof(int),
932 .proc_handler = proc_dointvec_minmax,
936 #endif /* CONFIG_SMP */
938 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
940 .procname = "unknown_nmi_panic",
941 .data = &unknown_nmi_panic,
942 .maxlen = sizeof (int),
944 .proc_handler = proc_dointvec,
947 #if defined(CONFIG_X86)
949 .procname = "panic_on_unrecovered_nmi",
950 .data = &panic_on_unrecovered_nmi,
951 .maxlen = sizeof(int),
953 .proc_handler = proc_dointvec,
956 .procname = "panic_on_io_nmi",
957 .data = &panic_on_io_nmi,
958 .maxlen = sizeof(int),
960 .proc_handler = proc_dointvec,
962 #ifdef CONFIG_DEBUG_STACKOVERFLOW
964 .procname = "panic_on_stackoverflow",
965 .data = &sysctl_panic_on_stackoverflow,
966 .maxlen = sizeof(int),
968 .proc_handler = proc_dointvec,
972 .procname = "bootloader_type",
973 .data = &bootloader_type,
974 .maxlen = sizeof (int),
976 .proc_handler = proc_dointvec,
979 .procname = "bootloader_version",
980 .data = &bootloader_version,
981 .maxlen = sizeof (int),
983 .proc_handler = proc_dointvec,
986 .procname = "kstack_depth_to_print",
987 .data = &kstack_depth_to_print,
988 .maxlen = sizeof(int),
990 .proc_handler = proc_dointvec,
993 .procname = "io_delay_type",
994 .data = &io_delay_type,
995 .maxlen = sizeof(int),
997 .proc_handler = proc_dointvec,
1000 #if defined(CONFIG_MMU)
1002 .procname = "randomize_va_space",
1003 .data = &randomize_va_space,
1004 .maxlen = sizeof(int),
1006 .proc_handler = proc_dointvec,
1009 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1011 .procname = "spin_retry",
1012 .data = &spin_retry,
1013 .maxlen = sizeof (int),
1015 .proc_handler = proc_dointvec,
1018 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1020 .procname = "acpi_video_flags",
1021 .data = &acpi_realmode_flags,
1022 .maxlen = sizeof (unsigned long),
1024 .proc_handler = proc_doulongvec_minmax,
1027 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1029 .procname = "ignore-unaligned-usertrap",
1030 .data = &no_unaligned_warning,
1031 .maxlen = sizeof (int),
1033 .proc_handler = proc_dointvec,
1038 .procname = "unaligned-dump-stack",
1039 .data = &unaligned_dump_stack,
1040 .maxlen = sizeof (int),
1042 .proc_handler = proc_dointvec,
1045 #ifdef CONFIG_DETECT_HUNG_TASK
1047 .procname = "hung_task_panic",
1048 .data = &sysctl_hung_task_panic,
1049 .maxlen = sizeof(int),
1051 .proc_handler = proc_dointvec_minmax,
1056 .procname = "hung_task_check_count",
1057 .data = &sysctl_hung_task_check_count,
1058 .maxlen = sizeof(int),
1060 .proc_handler = proc_dointvec_minmax,
1064 .procname = "hung_task_timeout_secs",
1065 .data = &sysctl_hung_task_timeout_secs,
1066 .maxlen = sizeof(unsigned long),
1068 .proc_handler = proc_dohung_task_timeout_secs,
1069 .extra2 = &hung_task_timeout_max,
1072 .procname = "hung_task_warnings",
1073 .data = &sysctl_hung_task_warnings,
1074 .maxlen = sizeof(int),
1076 .proc_handler = proc_dointvec_minmax,
1080 #ifdef CONFIG_COMPAT
1082 .procname = "compat-log",
1083 .data = &compat_log,
1084 .maxlen = sizeof (int),
1086 .proc_handler = proc_dointvec,
1089 #ifdef CONFIG_RT_MUTEXES
1091 .procname = "max_lock_depth",
1092 .data = &max_lock_depth,
1093 .maxlen = sizeof(int),
1095 .proc_handler = proc_dointvec,
1099 .procname = "poweroff_cmd",
1100 .data = &poweroff_cmd,
1101 .maxlen = POWEROFF_CMD_PATH_LEN,
1103 .proc_handler = proc_dostring,
1109 .child = key_sysctls,
1112 #ifdef CONFIG_PERF_EVENTS
1114 * User-space scripts rely on the existence of this file
1115 * as a feature check for perf_events being enabled.
1117 * So it's an ABI, do not remove!
1120 .procname = "perf_event_paranoid",
1121 .data = &sysctl_perf_event_paranoid,
1122 .maxlen = sizeof(sysctl_perf_event_paranoid),
1124 .proc_handler = proc_dointvec,
1127 .procname = "perf_event_mlock_kb",
1128 .data = &sysctl_perf_event_mlock,
1129 .maxlen = sizeof(sysctl_perf_event_mlock),
1131 .proc_handler = proc_dointvec,
1134 .procname = "perf_event_max_sample_rate",
1135 .data = &sysctl_perf_event_sample_rate,
1136 .maxlen = sizeof(sysctl_perf_event_sample_rate),
1138 .proc_handler = perf_proc_update_handler,
1142 .procname = "perf_cpu_time_max_percent",
1143 .data = &sysctl_perf_cpu_time_max_percent,
1144 .maxlen = sizeof(sysctl_perf_cpu_time_max_percent),
1146 .proc_handler = perf_cpu_time_max_percent_handler,
1148 .extra2 = &one_hundred,
1151 .procname = "perf_event_max_stack",
1152 .data = NULL, /* filled in by handler */
1153 .maxlen = sizeof(sysctl_perf_event_max_stack),
1155 .proc_handler = perf_event_max_stack_handler,
1157 .extra2 = &six_hundred_forty_kb,
1160 #ifdef CONFIG_KMEMCHECK
1162 .procname = "kmemcheck",
1163 .data = &kmemcheck_enabled,
1164 .maxlen = sizeof(int),
1166 .proc_handler = proc_dointvec,
1170 .procname = "panic_on_warn",
1171 .data = &panic_on_warn,
1172 .maxlen = sizeof(int),
1174 .proc_handler = proc_dointvec_minmax,
1178 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1180 .procname = "timer_migration",
1181 .data = &sysctl_timer_migration,
1182 .maxlen = sizeof(unsigned int),
1184 .proc_handler = timer_migration_handler,
1187 #ifdef CONFIG_BPF_SYSCALL
1189 .procname = "unprivileged_bpf_disabled",
1190 .data = &sysctl_unprivileged_bpf_disabled,
1191 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
1193 /* only handle a transition from default "0" to "1" */
1194 .proc_handler = proc_dointvec_minmax,
1202 static struct ctl_table vm_table[] = {
1204 .procname = "overcommit_memory",
1205 .data = &sysctl_overcommit_memory,
1206 .maxlen = sizeof(sysctl_overcommit_memory),
1208 .proc_handler = proc_dointvec_minmax,
1213 .procname = "panic_on_oom",
1214 .data = &sysctl_panic_on_oom,
1215 .maxlen = sizeof(sysctl_panic_on_oom),
1217 .proc_handler = proc_dointvec_minmax,
1222 .procname = "oom_kill_allocating_task",
1223 .data = &sysctl_oom_kill_allocating_task,
1224 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1226 .proc_handler = proc_dointvec,
1229 .procname = "oom_dump_tasks",
1230 .data = &sysctl_oom_dump_tasks,
1231 .maxlen = sizeof(sysctl_oom_dump_tasks),
1233 .proc_handler = proc_dointvec,
1236 .procname = "overcommit_ratio",
1237 .data = &sysctl_overcommit_ratio,
1238 .maxlen = sizeof(sysctl_overcommit_ratio),
1240 .proc_handler = overcommit_ratio_handler,
1243 .procname = "overcommit_kbytes",
1244 .data = &sysctl_overcommit_kbytes,
1245 .maxlen = sizeof(sysctl_overcommit_kbytes),
1247 .proc_handler = overcommit_kbytes_handler,
1250 .procname = "page-cluster",
1251 .data = &page_cluster,
1252 .maxlen = sizeof(int),
1254 .proc_handler = proc_dointvec_minmax,
1258 .procname = "dirty_background_ratio",
1259 .data = &dirty_background_ratio,
1260 .maxlen = sizeof(dirty_background_ratio),
1262 .proc_handler = dirty_background_ratio_handler,
1264 .extra2 = &one_hundred,
1267 .procname = "dirty_background_bytes",
1268 .data = &dirty_background_bytes,
1269 .maxlen = sizeof(dirty_background_bytes),
1271 .proc_handler = dirty_background_bytes_handler,
1275 .procname = "dirty_ratio",
1276 .data = &vm_dirty_ratio,
1277 .maxlen = sizeof(vm_dirty_ratio),
1279 .proc_handler = dirty_ratio_handler,
1281 .extra2 = &one_hundred,
1284 .procname = "dirty_bytes",
1285 .data = &vm_dirty_bytes,
1286 .maxlen = sizeof(vm_dirty_bytes),
1288 .proc_handler = dirty_bytes_handler,
1289 .extra1 = &dirty_bytes_min,
1292 .procname = "dirty_writeback_centisecs",
1293 .data = &dirty_writeback_interval,
1294 .maxlen = sizeof(dirty_writeback_interval),
1296 .proc_handler = dirty_writeback_centisecs_handler,
1299 .procname = "dirty_expire_centisecs",
1300 .data = &dirty_expire_interval,
1301 .maxlen = sizeof(dirty_expire_interval),
1303 .proc_handler = proc_dointvec_minmax,
1307 .procname = "dirtytime_expire_seconds",
1308 .data = &dirtytime_expire_interval,
1309 .maxlen = sizeof(dirty_expire_interval),
1311 .proc_handler = dirtytime_interval_handler,
1315 .procname = "nr_pdflush_threads",
1316 .mode = 0444 /* read-only */,
1317 .proc_handler = pdflush_proc_obsolete,
1320 .procname = "swappiness",
1321 .data = &vm_swappiness,
1322 .maxlen = sizeof(vm_swappiness),
1324 .proc_handler = proc_dointvec_minmax,
1326 .extra2 = &one_hundred,
1328 #ifdef CONFIG_HUGETLB_PAGE
1330 .procname = "nr_hugepages",
1332 .maxlen = sizeof(unsigned long),
1334 .proc_handler = hugetlb_sysctl_handler,
1338 .procname = "nr_hugepages_mempolicy",
1340 .maxlen = sizeof(unsigned long),
1342 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1346 .procname = "hugetlb_shm_group",
1347 .data = &sysctl_hugetlb_shm_group,
1348 .maxlen = sizeof(gid_t),
1350 .proc_handler = proc_dointvec,
1353 .procname = "hugepages_treat_as_movable",
1354 .data = &hugepages_treat_as_movable,
1355 .maxlen = sizeof(int),
1357 .proc_handler = proc_dointvec,
1360 .procname = "nr_overcommit_hugepages",
1362 .maxlen = sizeof(unsigned long),
1364 .proc_handler = hugetlb_overcommit_handler,
1368 .procname = "lowmem_reserve_ratio",
1369 .data = &sysctl_lowmem_reserve_ratio,
1370 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1372 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1375 .procname = "drop_caches",
1376 .data = &sysctl_drop_caches,
1377 .maxlen = sizeof(int),
1379 .proc_handler = drop_caches_sysctl_handler,
1383 #ifdef CONFIG_COMPACTION
1385 .procname = "compact_memory",
1386 .data = &sysctl_compact_memory,
1387 .maxlen = sizeof(int),
1389 .proc_handler = sysctl_compaction_handler,
1392 .procname = "extfrag_threshold",
1393 .data = &sysctl_extfrag_threshold,
1394 .maxlen = sizeof(int),
1396 .proc_handler = sysctl_extfrag_handler,
1397 .extra1 = &min_extfrag_threshold,
1398 .extra2 = &max_extfrag_threshold,
1401 .procname = "compact_unevictable_allowed",
1402 .data = &sysctl_compact_unevictable_allowed,
1403 .maxlen = sizeof(int),
1405 .proc_handler = proc_dointvec,
1410 #endif /* CONFIG_COMPACTION */
1412 .procname = "min_free_kbytes",
1413 .data = &min_free_kbytes,
1414 .maxlen = sizeof(min_free_kbytes),
1416 .proc_handler = min_free_kbytes_sysctl_handler,
1420 .procname = "watermark_scale_factor",
1421 .data = &watermark_scale_factor,
1422 .maxlen = sizeof(watermark_scale_factor),
1424 .proc_handler = watermark_scale_factor_sysctl_handler,
1426 .extra2 = &one_thousand,
1429 .procname = "percpu_pagelist_fraction",
1430 .data = &percpu_pagelist_fraction,
1431 .maxlen = sizeof(percpu_pagelist_fraction),
1433 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1438 .procname = "max_map_count",
1439 .data = &sysctl_max_map_count,
1440 .maxlen = sizeof(sysctl_max_map_count),
1442 .proc_handler = proc_dointvec_minmax,
1447 .procname = "nr_trim_pages",
1448 .data = &sysctl_nr_trim_pages,
1449 .maxlen = sizeof(sysctl_nr_trim_pages),
1451 .proc_handler = proc_dointvec_minmax,
1456 .procname = "laptop_mode",
1457 .data = &laptop_mode,
1458 .maxlen = sizeof(laptop_mode),
1460 .proc_handler = proc_dointvec_jiffies,
1463 .procname = "block_dump",
1464 .data = &block_dump,
1465 .maxlen = sizeof(block_dump),
1467 .proc_handler = proc_dointvec,
1471 .procname = "vfs_cache_pressure",
1472 .data = &sysctl_vfs_cache_pressure,
1473 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1475 .proc_handler = proc_dointvec,
1478 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1480 .procname = "legacy_va_layout",
1481 .data = &sysctl_legacy_va_layout,
1482 .maxlen = sizeof(sysctl_legacy_va_layout),
1484 .proc_handler = proc_dointvec,
1490 .procname = "zone_reclaim_mode",
1491 .data = &zone_reclaim_mode,
1492 .maxlen = sizeof(zone_reclaim_mode),
1494 .proc_handler = proc_dointvec,
1498 .procname = "min_unmapped_ratio",
1499 .data = &sysctl_min_unmapped_ratio,
1500 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1502 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1504 .extra2 = &one_hundred,
1507 .procname = "min_slab_ratio",
1508 .data = &sysctl_min_slab_ratio,
1509 .maxlen = sizeof(sysctl_min_slab_ratio),
1511 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1513 .extra2 = &one_hundred,
1518 .procname = "stat_interval",
1519 .data = &sysctl_stat_interval,
1520 .maxlen = sizeof(sysctl_stat_interval),
1522 .proc_handler = proc_dointvec_jiffies,
1525 .procname = "stat_refresh",
1529 .proc_handler = vmstat_refresh,
1534 .procname = "mmap_min_addr",
1535 .data = &dac_mmap_min_addr,
1536 .maxlen = sizeof(unsigned long),
1538 .proc_handler = mmap_min_addr_handler,
1543 .procname = "numa_zonelist_order",
1544 .data = &numa_zonelist_order,
1545 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1547 .proc_handler = numa_zonelist_order_handler,
1550 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1551 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1553 .procname = "vdso_enabled",
1554 #ifdef CONFIG_X86_32
1555 .data = &vdso32_enabled,
1556 .maxlen = sizeof(vdso32_enabled),
1558 .data = &vdso_enabled,
1559 .maxlen = sizeof(vdso_enabled),
1562 .proc_handler = proc_dointvec,
1566 #ifdef CONFIG_HIGHMEM
1568 .procname = "highmem_is_dirtyable",
1569 .data = &vm_highmem_is_dirtyable,
1570 .maxlen = sizeof(vm_highmem_is_dirtyable),
1572 .proc_handler = proc_dointvec_minmax,
1577 #ifdef CONFIG_MEMORY_FAILURE
1579 .procname = "memory_failure_early_kill",
1580 .data = &sysctl_memory_failure_early_kill,
1581 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1583 .proc_handler = proc_dointvec_minmax,
1588 .procname = "memory_failure_recovery",
1589 .data = &sysctl_memory_failure_recovery,
1590 .maxlen = sizeof(sysctl_memory_failure_recovery),
1592 .proc_handler = proc_dointvec_minmax,
1598 .procname = "user_reserve_kbytes",
1599 .data = &sysctl_user_reserve_kbytes,
1600 .maxlen = sizeof(sysctl_user_reserve_kbytes),
1602 .proc_handler = proc_doulongvec_minmax,
1605 .procname = "admin_reserve_kbytes",
1606 .data = &sysctl_admin_reserve_kbytes,
1607 .maxlen = sizeof(sysctl_admin_reserve_kbytes),
1609 .proc_handler = proc_doulongvec_minmax,
1611 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1613 .procname = "mmap_rnd_bits",
1614 .data = &mmap_rnd_bits,
1615 .maxlen = sizeof(mmap_rnd_bits),
1617 .proc_handler = proc_dointvec_minmax,
1618 .extra1 = (void *)&mmap_rnd_bits_min,
1619 .extra2 = (void *)&mmap_rnd_bits_max,
1622 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1624 .procname = "mmap_rnd_compat_bits",
1625 .data = &mmap_rnd_compat_bits,
1626 .maxlen = sizeof(mmap_rnd_compat_bits),
1628 .proc_handler = proc_dointvec_minmax,
1629 .extra1 = (void *)&mmap_rnd_compat_bits_min,
1630 .extra2 = (void *)&mmap_rnd_compat_bits_max,
1636 static struct ctl_table fs_table[] = {
1638 .procname = "inode-nr",
1639 .data = &inodes_stat,
1640 .maxlen = 2*sizeof(long),
1642 .proc_handler = proc_nr_inodes,
1645 .procname = "inode-state",
1646 .data = &inodes_stat,
1647 .maxlen = 7*sizeof(long),
1649 .proc_handler = proc_nr_inodes,
1652 .procname = "file-nr",
1653 .data = &files_stat,
1654 .maxlen = sizeof(files_stat),
1656 .proc_handler = proc_nr_files,
1659 .procname = "file-max",
1660 .data = &files_stat.max_files,
1661 .maxlen = sizeof(files_stat.max_files),
1663 .proc_handler = proc_doulongvec_minmax,
1666 .procname = "nr_open",
1667 .data = &sysctl_nr_open,
1668 .maxlen = sizeof(int),
1670 .proc_handler = proc_dointvec_minmax,
1671 .extra1 = &sysctl_nr_open_min,
1672 .extra2 = &sysctl_nr_open_max,
1675 .procname = "dentry-state",
1676 .data = &dentry_stat,
1677 .maxlen = 6*sizeof(long),
1679 .proc_handler = proc_nr_dentry,
1682 .procname = "overflowuid",
1683 .data = &fs_overflowuid,
1684 .maxlen = sizeof(int),
1686 .proc_handler = proc_dointvec_minmax,
1687 .extra1 = &minolduid,
1688 .extra2 = &maxolduid,
1691 .procname = "overflowgid",
1692 .data = &fs_overflowgid,
1693 .maxlen = sizeof(int),
1695 .proc_handler = proc_dointvec_minmax,
1696 .extra1 = &minolduid,
1697 .extra2 = &maxolduid,
1699 #ifdef CONFIG_FILE_LOCKING
1701 .procname = "leases-enable",
1702 .data = &leases_enable,
1703 .maxlen = sizeof(int),
1705 .proc_handler = proc_dointvec,
1708 #ifdef CONFIG_DNOTIFY
1710 .procname = "dir-notify-enable",
1711 .data = &dir_notify_enable,
1712 .maxlen = sizeof(int),
1714 .proc_handler = proc_dointvec,
1718 #ifdef CONFIG_FILE_LOCKING
1720 .procname = "lease-break-time",
1721 .data = &lease_break_time,
1722 .maxlen = sizeof(int),
1724 .proc_handler = proc_dointvec,
1729 .procname = "aio-nr",
1731 .maxlen = sizeof(aio_nr),
1733 .proc_handler = proc_doulongvec_minmax,
1736 .procname = "aio-max-nr",
1737 .data = &aio_max_nr,
1738 .maxlen = sizeof(aio_max_nr),
1740 .proc_handler = proc_doulongvec_minmax,
1742 #endif /* CONFIG_AIO */
1743 #ifdef CONFIG_INOTIFY_USER
1745 .procname = "inotify",
1747 .child = inotify_table,
1752 .procname = "epoll",
1754 .child = epoll_table,
1759 .procname = "protected_symlinks",
1760 .data = &sysctl_protected_symlinks,
1761 .maxlen = sizeof(int),
1763 .proc_handler = proc_dointvec_minmax,
1768 .procname = "protected_hardlinks",
1769 .data = &sysctl_protected_hardlinks,
1770 .maxlen = sizeof(int),
1772 .proc_handler = proc_dointvec_minmax,
1777 .procname = "suid_dumpable",
1778 .data = &suid_dumpable,
1779 .maxlen = sizeof(int),
1781 .proc_handler = proc_dointvec_minmax_coredump,
1785 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1787 .procname = "binfmt_misc",
1789 .child = sysctl_mount_point,
1793 .procname = "pipe-max-size",
1794 .data = &pipe_max_size,
1795 .maxlen = sizeof(int),
1797 .proc_handler = &pipe_proc_fn,
1798 .extra1 = &pipe_min_size,
1801 .procname = "pipe-user-pages-hard",
1802 .data = &pipe_user_pages_hard,
1803 .maxlen = sizeof(pipe_user_pages_hard),
1805 .proc_handler = proc_doulongvec_minmax,
1808 .procname = "pipe-user-pages-soft",
1809 .data = &pipe_user_pages_soft,
1810 .maxlen = sizeof(pipe_user_pages_soft),
1812 .proc_handler = proc_doulongvec_minmax,
1817 static struct ctl_table debug_table[] = {
1818 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1820 .procname = "exception-trace",
1821 .data = &show_unhandled_signals,
1822 .maxlen = sizeof(int),
1824 .proc_handler = proc_dointvec
1827 #if defined(CONFIG_OPTPROBES)
1829 .procname = "kprobes-optimization",
1830 .data = &sysctl_kprobes_optimization,
1831 .maxlen = sizeof(int),
1833 .proc_handler = proc_kprobes_optimization_handler,
1841 static struct ctl_table dev_table[] = {
1845 int __init sysctl_init(void)
1847 struct ctl_table_header *hdr;
1849 hdr = register_sysctl_table(sysctl_base_table);
1850 kmemleak_not_leak(hdr);
1854 #endif /* CONFIG_SYSCTL */
1860 #ifdef CONFIG_PROC_SYSCTL
1862 static int _proc_do_string(char *data, int maxlen, int write,
1863 char __user *buffer,
1864 size_t *lenp, loff_t *ppos)
1870 if (!data || !maxlen || !*lenp) {
1876 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1877 /* Only continue writes not past the end of buffer. */
1879 if (len > maxlen - 1)
1886 /* Start writing from beginning of buffer. */
1892 while ((p - buffer) < *lenp && len < maxlen - 1) {
1893 if (get_user(c, p++))
1895 if (c == 0 || c == '\n')
1916 if (copy_to_user(buffer, data, len))
1919 if (put_user('\n', buffer + len))
1929 static void warn_sysctl_write(struct ctl_table *table)
1931 pr_warn_once("%s wrote to %s when file position was not 0!\n"
1932 "This will not be supported in the future. To silence this\n"
1933 "warning, set kernel.sysctl_writes_strict = -1\n",
1934 current->comm, table->procname);
1938 * proc_dostring - read a string sysctl
1939 * @table: the sysctl table
1940 * @write: %TRUE if this is a write to the sysctl file
1941 * @buffer: the user buffer
1942 * @lenp: the size of the user buffer
1943 * @ppos: file position
1945 * Reads/writes a string from/to the user buffer. If the kernel
1946 * buffer provided is not large enough to hold the string, the
1947 * string is truncated. The copied string is %NULL-terminated.
1948 * If the string is being read by the user process, it is copied
1949 * and a newline '\n' is added. It is truncated if the buffer is
1952 * Returns 0 on success.
1954 int proc_dostring(struct ctl_table *table, int write,
1955 void __user *buffer, size_t *lenp, loff_t *ppos)
1957 if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1958 warn_sysctl_write(table);
1960 return _proc_do_string((char *)(table->data), table->maxlen, write,
1961 (char __user *)buffer, lenp, ppos);
1964 static size_t proc_skip_spaces(char **buf)
1967 char *tmp = skip_spaces(*buf);
1973 static void proc_skip_char(char **buf, size_t *size, const char v)
1983 #define TMPBUFLEN 22
1985 * proc_get_long - reads an ASCII formatted integer from a user buffer
1987 * @buf: a kernel buffer
1988 * @size: size of the kernel buffer
1989 * @val: this is where the number will be stored
1990 * @neg: set to %TRUE if number is negative
1991 * @perm_tr: a vector which contains the allowed trailers
1992 * @perm_tr_len: size of the perm_tr vector
1993 * @tr: pointer to store the trailer character
1995 * In case of success %0 is returned and @buf and @size are updated with
1996 * the amount of bytes read. If @tr is non-NULL and a trailing
1997 * character exists (size is non-zero after returning from this
1998 * function), @tr is updated with the trailing character.
2000 static int proc_get_long(char **buf, size_t *size,
2001 unsigned long *val, bool *neg,
2002 const char *perm_tr, unsigned perm_tr_len, char *tr)
2005 char *p, tmp[TMPBUFLEN];
2011 if (len > TMPBUFLEN - 1)
2012 len = TMPBUFLEN - 1;
2014 memcpy(tmp, *buf, len);
2018 if (*p == '-' && *size > 1) {
2026 *val = simple_strtoul(p, &p, 0);
2030 /* We don't know if the next char is whitespace thus we may accept
2031 * invalid integers (e.g. 1234...a) or two integers instead of one
2032 * (e.g. 123...1). So lets not allow such large numbers. */
2033 if (len == TMPBUFLEN - 1)
2036 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2039 if (tr && (len < *size))
2049 * proc_put_long - converts an integer to a decimal ASCII formatted string
2051 * @buf: the user buffer
2052 * @size: the size of the user buffer
2053 * @val: the integer to be converted
2054 * @neg: sign of the number, %TRUE for negative
2056 * In case of success %0 is returned and @buf and @size are updated with
2057 * the amount of bytes written.
2059 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2063 char tmp[TMPBUFLEN], *p = tmp;
2065 sprintf(p, "%s%lu", neg ? "-" : "", val);
2069 if (copy_to_user(*buf, tmp, len))
2077 static int proc_put_char(void __user **buf, size_t *size, char c)
2080 char __user **buffer = (char __user **)buf;
2081 if (put_user(c, *buffer))
2083 (*size)--, (*buffer)++;
2089 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2091 int write, void *data)
2095 if (*lvalp > (unsigned long) INT_MAX + 1)
2099 if (*lvalp > (unsigned long) INT_MAX)
2107 *lvalp = -(unsigned long)val;
2110 *lvalp = (unsigned long)val;
2116 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2118 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2119 int write, void __user *buffer,
2120 size_t *lenp, loff_t *ppos,
2121 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2122 int write, void *data),
2125 int *i, vleft, first = 1, err = 0;
2127 char *kbuf = NULL, *p;
2129 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2134 i = (int *) tbl_data;
2135 vleft = table->maxlen / sizeof(*i);
2139 conv = do_proc_dointvec_conv;
2143 switch (sysctl_writes_strict) {
2144 case SYSCTL_WRITES_STRICT:
2146 case SYSCTL_WRITES_WARN:
2147 warn_sysctl_write(table);
2154 if (left > PAGE_SIZE - 1)
2155 left = PAGE_SIZE - 1;
2156 p = kbuf = memdup_user_nul(buffer, left);
2158 return PTR_ERR(kbuf);
2161 for (; left && vleft--; i++, first=0) {
2166 left -= proc_skip_spaces(&p);
2170 err = proc_get_long(&p, &left, &lval, &neg,
2172 sizeof(proc_wspace_sep), NULL);
2175 if (conv(&neg, &lval, i, 1, data)) {
2180 if (conv(&neg, &lval, i, 0, data)) {
2185 err = proc_put_char(&buffer, &left, '\t');
2188 err = proc_put_long(&buffer, &left, lval, neg);
2194 if (!write && !first && left && !err)
2195 err = proc_put_char(&buffer, &left, '\n');
2196 if (write && !err && left)
2197 left -= proc_skip_spaces(&p);
2201 return err ? : -EINVAL;
2209 static int do_proc_dointvec(struct ctl_table *table, int write,
2210 void __user *buffer, size_t *lenp, loff_t *ppos,
2211 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2212 int write, void *data),
2215 return __do_proc_dointvec(table->data, table, write,
2216 buffer, lenp, ppos, conv, data);
2220 * proc_dointvec - read a vector of integers
2221 * @table: the sysctl table
2222 * @write: %TRUE if this is a write to the sysctl file
2223 * @buffer: the user buffer
2224 * @lenp: the size of the user buffer
2225 * @ppos: file position
2227 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2228 * values from/to the user buffer, treated as an ASCII string.
2230 * Returns 0 on success.
2232 int proc_dointvec(struct ctl_table *table, int write,
2233 void __user *buffer, size_t *lenp, loff_t *ppos)
2235 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2240 * Taint values can only be increased
2241 * This means we can safely use a temporary.
2243 static int proc_taint(struct ctl_table *table, int write,
2244 void __user *buffer, size_t *lenp, loff_t *ppos)
2247 unsigned long tmptaint = get_taint();
2250 if (write && !capable(CAP_SYS_ADMIN))
2255 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2261 * Poor man's atomic or. Not worth adding a primitive
2262 * to everyone's atomic.h for this
2265 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2266 if ((tmptaint >> i) & 1)
2267 add_taint(i, LOCKDEP_STILL_OK);
2274 #ifdef CONFIG_PRINTK
2275 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2276 void __user *buffer, size_t *lenp, loff_t *ppos)
2278 if (write && !capable(CAP_SYS_ADMIN))
2281 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2285 struct do_proc_dointvec_minmax_conv_param {
2290 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2292 int write, void *data)
2294 struct do_proc_dointvec_minmax_conv_param *param = data;
2296 int val = *negp ? -*lvalp : *lvalp;
2297 if ((param->min && *param->min > val) ||
2298 (param->max && *param->max < val))
2305 *lvalp = -(unsigned long)val;
2308 *lvalp = (unsigned long)val;
2315 * proc_dointvec_minmax - read a vector of integers with min/max values
2316 * @table: the sysctl table
2317 * @write: %TRUE if this is a write to the sysctl file
2318 * @buffer: the user buffer
2319 * @lenp: the size of the user buffer
2320 * @ppos: file position
2322 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2323 * values from/to the user buffer, treated as an ASCII string.
2325 * This routine will ensure the values are within the range specified by
2326 * table->extra1 (min) and table->extra2 (max).
2328 * Returns 0 on success.
2330 int proc_dointvec_minmax(struct ctl_table *table, int write,
2331 void __user *buffer, size_t *lenp, loff_t *ppos)
2333 struct do_proc_dointvec_minmax_conv_param param = {
2334 .min = (int *) table->extra1,
2335 .max = (int *) table->extra2,
2337 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2338 do_proc_dointvec_minmax_conv, ¶m);
2341 static void validate_coredump_safety(void)
2343 #ifdef CONFIG_COREDUMP
2344 if (suid_dumpable == SUID_DUMP_ROOT &&
2345 core_pattern[0] != '/' && core_pattern[0] != '|') {
2346 printk(KERN_WARNING "Unsafe core_pattern used with "\
2347 "suid_dumpable=2. Pipe handler or fully qualified "\
2348 "core dump path required.\n");
2353 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2354 void __user *buffer, size_t *lenp, loff_t *ppos)
2356 int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2358 validate_coredump_safety();
2362 #ifdef CONFIG_COREDUMP
2363 static int proc_dostring_coredump(struct ctl_table *table, int write,
2364 void __user *buffer, size_t *lenp, loff_t *ppos)
2366 int error = proc_dostring(table, write, buffer, lenp, ppos);
2368 validate_coredump_safety();
2373 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2374 void __user *buffer,
2375 size_t *lenp, loff_t *ppos,
2376 unsigned long convmul,
2377 unsigned long convdiv)
2379 unsigned long *i, *min, *max;
2380 int vleft, first = 1, err = 0;
2382 char *kbuf = NULL, *p;
2384 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2389 i = (unsigned long *) data;
2390 min = (unsigned long *) table->extra1;
2391 max = (unsigned long *) table->extra2;
2392 vleft = table->maxlen / sizeof(unsigned long);
2397 switch (sysctl_writes_strict) {
2398 case SYSCTL_WRITES_STRICT:
2400 case SYSCTL_WRITES_WARN:
2401 warn_sysctl_write(table);
2408 if (left > PAGE_SIZE - 1)
2409 left = PAGE_SIZE - 1;
2410 p = kbuf = memdup_user_nul(buffer, left);
2412 return PTR_ERR(kbuf);
2415 for (; left && vleft--; i++, first = 0) {
2421 left -= proc_skip_spaces(&p);
2423 err = proc_get_long(&p, &left, &val, &neg,
2425 sizeof(proc_wspace_sep), NULL);
2430 if ((min && val < *min) || (max && val > *max))
2434 val = convdiv * (*i) / convmul;
2436 err = proc_put_char(&buffer, &left, '\t');
2440 err = proc_put_long(&buffer, &left, val, false);
2446 if (!write && !first && left && !err)
2447 err = proc_put_char(&buffer, &left, '\n');
2449 left -= proc_skip_spaces(&p);
2453 return err ? : -EINVAL;
2461 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2462 void __user *buffer,
2463 size_t *lenp, loff_t *ppos,
2464 unsigned long convmul,
2465 unsigned long convdiv)
2467 return __do_proc_doulongvec_minmax(table->data, table, write,
2468 buffer, lenp, ppos, convmul, convdiv);
2472 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2473 * @table: the sysctl table
2474 * @write: %TRUE if this is a write to the sysctl file
2475 * @buffer: the user buffer
2476 * @lenp: the size of the user buffer
2477 * @ppos: file position
2479 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2480 * values from/to the user buffer, treated as an ASCII string.
2482 * This routine will ensure the values are within the range specified by
2483 * table->extra1 (min) and table->extra2 (max).
2485 * Returns 0 on success.
2487 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2488 void __user *buffer, size_t *lenp, loff_t *ppos)
2490 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2494 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2495 * @table: the sysctl table
2496 * @write: %TRUE if this is a write to the sysctl file
2497 * @buffer: the user buffer
2498 * @lenp: the size of the user buffer
2499 * @ppos: file position
2501 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2502 * values from/to the user buffer, treated as an ASCII string. The values
2503 * are treated as milliseconds, and converted to jiffies when they are stored.
2505 * This routine will ensure the values are within the range specified by
2506 * table->extra1 (min) and table->extra2 (max).
2508 * Returns 0 on success.
2510 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2511 void __user *buffer,
2512 size_t *lenp, loff_t *ppos)
2514 return do_proc_doulongvec_minmax(table, write, buffer,
2515 lenp, ppos, HZ, 1000l);
2519 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2521 int write, void *data)
2524 if (*lvalp > LONG_MAX / HZ)
2526 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2532 lval = -(unsigned long)val;
2535 lval = (unsigned long)val;
2542 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2544 int write, void *data)
2547 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2549 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2555 lval = -(unsigned long)val;
2558 lval = (unsigned long)val;
2560 *lvalp = jiffies_to_clock_t(lval);
2565 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2567 int write, void *data)
2570 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2580 lval = -(unsigned long)val;
2583 lval = (unsigned long)val;
2585 *lvalp = jiffies_to_msecs(lval);
2591 * proc_dointvec_jiffies - read a vector of integers as seconds
2592 * @table: the sysctl table
2593 * @write: %TRUE if this is a write to the sysctl file
2594 * @buffer: the user buffer
2595 * @lenp: the size of the user buffer
2596 * @ppos: file position
2598 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2599 * values from/to the user buffer, treated as an ASCII string.
2600 * The values read are assumed to be in seconds, and are converted into
2603 * Returns 0 on success.
2605 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2606 void __user *buffer, size_t *lenp, loff_t *ppos)
2608 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2609 do_proc_dointvec_jiffies_conv,NULL);
2613 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2614 * @table: the sysctl table
2615 * @write: %TRUE if this is a write to the sysctl file
2616 * @buffer: the user buffer
2617 * @lenp: the size of the user buffer
2618 * @ppos: pointer to the file position
2620 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2621 * values from/to the user buffer, treated as an ASCII string.
2622 * The values read are assumed to be in 1/USER_HZ seconds, and
2623 * are converted into jiffies.
2625 * Returns 0 on success.
2627 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2628 void __user *buffer, size_t *lenp, loff_t *ppos)
2630 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2631 do_proc_dointvec_userhz_jiffies_conv,NULL);
2635 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2636 * @table: the sysctl table
2637 * @write: %TRUE if this is a write to the sysctl file
2638 * @buffer: the user buffer
2639 * @lenp: the size of the user buffer
2640 * @ppos: file position
2641 * @ppos: the current position in the file
2643 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2644 * values from/to the user buffer, treated as an ASCII string.
2645 * The values read are assumed to be in 1/1000 seconds, and
2646 * are converted into jiffies.
2648 * Returns 0 on success.
2650 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2651 void __user *buffer, size_t *lenp, loff_t *ppos)
2653 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2654 do_proc_dointvec_ms_jiffies_conv, NULL);
2657 static int proc_do_cad_pid(struct ctl_table *table, int write,
2658 void __user *buffer, size_t *lenp, loff_t *ppos)
2660 struct pid *new_pid;
2664 tmp = pid_vnr(cad_pid);
2666 r = __do_proc_dointvec(&tmp, table, write, buffer,
2667 lenp, ppos, NULL, NULL);
2671 new_pid = find_get_pid(tmp);
2675 put_pid(xchg(&cad_pid, new_pid));
2680 * proc_do_large_bitmap - read/write from/to a large bitmap
2681 * @table: the sysctl table
2682 * @write: %TRUE if this is a write to the sysctl file
2683 * @buffer: the user buffer
2684 * @lenp: the size of the user buffer
2685 * @ppos: file position
2687 * The bitmap is stored at table->data and the bitmap length (in bits)
2690 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2691 * large bitmaps may be represented in a compact manner. Writing into
2692 * the file will clear the bitmap then update it with the given input.
2694 * Returns 0 on success.
2696 int proc_do_large_bitmap(struct ctl_table *table, int write,
2697 void __user *buffer, size_t *lenp, loff_t *ppos)
2701 size_t left = *lenp;
2702 unsigned long bitmap_len = table->maxlen;
2703 unsigned long *bitmap = *(unsigned long **) table->data;
2704 unsigned long *tmp_bitmap = NULL;
2705 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2707 if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2715 if (left > PAGE_SIZE - 1)
2716 left = PAGE_SIZE - 1;
2718 p = kbuf = memdup_user_nul(buffer, left);
2720 return PTR_ERR(kbuf);
2722 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2728 proc_skip_char(&p, &left, '\n');
2729 while (!err && left) {
2730 unsigned long val_a, val_b;
2733 err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2737 if (val_a >= bitmap_len || neg) {
2749 err = proc_get_long(&p, &left, &val_b,
2750 &neg, tr_b, sizeof(tr_b),
2754 if (val_b >= bitmap_len || neg ||
2765 bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2767 proc_skip_char(&p, &left, '\n');
2771 unsigned long bit_a, bit_b = 0;
2774 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2775 if (bit_a >= bitmap_len)
2777 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2781 err = proc_put_char(&buffer, &left, ',');
2785 err = proc_put_long(&buffer, &left, bit_a, false);
2788 if (bit_a != bit_b) {
2789 err = proc_put_char(&buffer, &left, '-');
2792 err = proc_put_long(&buffer, &left, bit_b, false);
2800 err = proc_put_char(&buffer, &left, '\n');
2806 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2808 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2820 #else /* CONFIG_PROC_SYSCTL */
2822 int proc_dostring(struct ctl_table *table, int write,
2823 void __user *buffer, size_t *lenp, loff_t *ppos)
2828 int proc_dointvec(struct ctl_table *table, int write,
2829 void __user *buffer, size_t *lenp, loff_t *ppos)
2834 int proc_dointvec_minmax(struct ctl_table *table, int write,
2835 void __user *buffer, size_t *lenp, loff_t *ppos)
2840 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2841 void __user *buffer, size_t *lenp, loff_t *ppos)
2846 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2847 void __user *buffer, size_t *lenp, loff_t *ppos)
2852 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2853 void __user *buffer, size_t *lenp, loff_t *ppos)
2858 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2859 void __user *buffer, size_t *lenp, loff_t *ppos)
2864 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2865 void __user *buffer,
2866 size_t *lenp, loff_t *ppos)
2872 #endif /* CONFIG_PROC_SYSCTL */
2875 * No sense putting this after each symbol definition, twice,
2876 * exception granted :-)
2878 EXPORT_SYMBOL(proc_dointvec);
2879 EXPORT_SYMBOL(proc_dointvec_jiffies);
2880 EXPORT_SYMBOL(proc_dointvec_minmax);
2881 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2882 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2883 EXPORT_SYMBOL(proc_dostring);
2884 EXPORT_SYMBOL(proc_doulongvec_minmax);
2885 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);