/*
* sysctl.c: General linux system control interface
*
* Begun 24 March 1995, Stephen Tweedie
* Added /proc support, Dec 1995
* Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
* Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
* Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
* Dynamic registration fixes, Stephen Tweedie.
* Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
* Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
* Horn.
* Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
* Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
* Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
* Wendling.
* The list_for_each() macro wasn't appropriate for the sysctl loop.
* Removed it and replaced it with older style, 03/23/00, Bill Wendling
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/security.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/net.h>
#include <linux/sysrq.h>
#include <linux/highuid.h>
#include <linux/writeback.h>
#include <linux/hugetlb.h>
#include <linux/initrd.h>
#include <linux/key.h>
#include <linux/times.h>
#include <linux/limits.h>
#include <linux/dcache.h>
#include <linux/syscalls.h>
#include <linux/vmstat.h>
#include <linux/nfs_fs.h>
#include <linux/acpi.h>
#include <linux/reboot.h>
#include <linux/ftrace.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#ifdef CONFIG_X86
#include <asm/nmi.h>
#include <asm/stacktrace.h>
#include <asm/io.h>
#endif
static int deprecated_sysctl_warning(struct __sysctl_args *args);
#if defined(CONFIG_SYSCTL)
/* External variables not in a header file. */
extern int C_A_D;
extern int print_fatal_signals;
extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern int sysctl_panic_on_oom;
extern int sysctl_oom_kill_allocating_task;
extern int sysctl_oom_dump_tasks;
extern int max_threads;
extern int core_uses_pid;
extern int suid_dumpable;
extern char core_pattern[];
extern int pid_max;
extern int min_free_kbytes;
extern int pid_max_min, pid_max_max;
extern int sysctl_drop_caches;
extern int percpu_pagelist_fraction;
extern int compat_log;
extern int maps_protect;
extern int latencytop_enabled;
extern int sysctl_nr_open_min, sysctl_nr_open_max;
#ifdef CONFIG_RCU_TORTURE_TEST
extern int rcutorture_runnable;
#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
/* Constants used for minimum and maximum */
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP)
static int one = 1;
#endif
#ifdef CONFIG_DETECT_SOFTLOCKUP
static int sixty = 60;
static int neg_one = -1;
#endif
#ifdef CONFIG_MMU
static int two = 2;
#endif
static int zero;
static int one_hundred = 100;
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
static int minolduid;
static int min_percpu_pagelist_fract = 8;
static int ngroups_max = NGROUPS_MAX;
#ifdef CONFIG_MODULES
extern char modprobe_path[];
#endif
#ifdef CONFIG_CHR_DEV_SG
extern int sg_big_buff;
#endif
#ifdef __sparc__
extern char reboot_command [];
extern int stop_a_enabled;
extern int scons_pwroff;
#endif
#ifdef __hppa__
extern int pwrsw_enabled;
extern int unaligned_enabled;
#endif
#ifdef CONFIG_S390
#ifdef CONFIG_MATHEMU
extern int sysctl_ieee_emulation_warnings;
#endif
extern int sysctl_userprocess_debug;
extern int spin_retry;
#endif
#ifdef CONFIG_BSD_PROCESS_ACCT
extern int acct_parm[];
#endif
#ifdef CONFIG_IA64
extern int no_unaligned_warning;
#endif
#ifdef CONFIG_RT_MUTEXES
extern int max_lock_depth;
#endif
#ifdef CONFIG_PROC_SYSCTL
static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
#endif
static struct ctl_table root_table[];
static struct ctl_table_root sysctl_table_root;
static struct ctl_table_header root_table_header = {
.ctl_table = root_table,
.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
.root = &sysctl_table_root,
.set = &sysctl_table_root.default_set,
};
static struct ctl_table_root sysctl_table_root = {
.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
.default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
};
static struct ctl_table kern_table[];
static struct ctl_table vm_table[];
static struct ctl_table fs_table[];
static struct ctl_table debug_table[];
static struct ctl_table dev_table[];
extern struct ctl_table random_table[];
#ifdef CONFIG_INOTIFY_USER
extern struct ctl_table inotify_table[];
#endif
#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
int sysctl_legacy_va_layout;
#endif
extern int prove_locking;
extern int lock_stat;
/* The default sysctl tables: */
static struct ctl_table root_table[] = {
{
.ctl_name = CTL_KERN,
.procname = "kernel",
.mode = 0555,
.child = kern_table,
},
{
.ctl_name = CTL_VM,
.procname = "vm",
.mode = 0555,
.child = vm_table,
},
{
.ctl_name = CTL_FS,
.procname = "fs",
.mode = 0555,
.child = fs_table,
},
{
.ctl_name = CTL_DEBUG,
.procname = "debug",
.mode = 0555,
.child = debug_table,
},
{
.ctl_name = CTL_DEV,
.procname = "dev",
.mode = 0555,
.child = dev_table,
},
/*
* NOTE: do not add new entries to this table unless you have read
* Documentation/sysctl/ctl_unnumbered.txt
*/
{ .ctl_name = 0 }
};
#ifdef CONFIG_SCHED_DEBUG
static int min_sched_granularity_ns = 100000; /* 100 usecs */
static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
static int min_wakeup_granularity_ns; /* 0 usecs */
static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
#endif
static struct ctl_table kern_table[] = {
#ifdef CONFIG_SCHED_DEBUG
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_min_granularity_ns",
.data = &sysctl_sched_min_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &sched_nr_latency_handler,
.strategy = &sysctl_intvec,
.extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_latency_ns",
.data = &sysctl_sched_latency,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &sched_nr_latency_handler,
.strategy = &sysctl_intvec,
.extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_wakeup_granularity_ns",
.data = &sysctl_sched_wakeup_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &min_wakeup_granularity_ns,
.extra2 = &max_wakeup_granularity_ns,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_shares_ratelimit",
.data = &sysctl_sched_shares_ratelimit,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_child_runs_first",
.data = &sysctl_sched_child_runs_first,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_features",
.data = &sysctl_sched_features,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_migration_cost",
.data = &sysctl_sched_migration_cost,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_nr_migrate",
.data = &sysctl_sched_nr_migrate,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_rt_period_us",
.data = &sysctl_sched_rt_period,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &sched_rt_handler,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_rt_runtime_us",
.data = &sysctl_sched_rt_runtime,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &sched_rt_handler,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_compat_yield",
.data = &sysctl_sched_compat_yield,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#ifdef CONFIG_PROVE_LOCKING
{
.ctl_name = CTL_UNNUMBERED,
.procname = "prove_locking",
.data = &prove_locking,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#ifdef CONFIG_LOCK_STAT
{
.ctl_name = CTL_UNNUMBERED,
.procname = "lock_stat",
.data = &lock_stat,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
{
.ctl_name = KERN_PANIC,
.procname = "panic",
.data = &panic_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = KERN_CORE_USES_PID,
.procname = "core_uses_pid",
.data = &core_uses_pid,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = KERN_CORE_PATTERN,
.procname = "core_pattern",
.data = core_pattern,
.maxlen = CORENAME_MAX_SIZE,
.mode = 0644,
.proc_handler = &proc_dostring,
.strategy = &sysctl_string,
},
#ifdef CONFIG_PROC_SYSCTL
{
.procname = "tainted",
.data = &tainted,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_taint,
},
#endif
|