sysctl.c 68.5 KB
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/*
 * 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>
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#include <linux/security.h>
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#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/smp_lock.h>
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#include <linux/fs.h>
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#include <linux/init.h>
#include <linux/kernel.h>
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#include <linux/kobject.h>
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#include <linux/net.h>
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#include <linux/sysrq.h>
#include <linux/highuid.h>
#include <linux/writeback.h>
#include <linux/hugetlb.h>
#include <linux/initrd.h>
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#include <linux/key.h>
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#include <linux/times.h>
#include <linux/limits.h>
#include <linux/dcache.h>
#include <linux/syscalls.h>
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#include <linux/vmstat.h>
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#include <linux/nfs_fs.h>
#include <linux/acpi.h>
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#include <linux/reboot.h>
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#include <linux/ftrace.h>
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#include <asm/uaccess.h>
#include <asm/processor.h>

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#ifdef CONFIG_X86
#include <asm/nmi.h>
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#include <asm/stacktrace.h>
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#include <asm/io.h>
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#endif

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static int deprecated_sysctl_warning(struct __sysctl_args *args);

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#if defined(CONFIG_SYSCTL)

/* External variables not in a header file. */
extern int C_A_D;
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extern int print_fatal_signals;
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extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
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extern int sysctl_panic_on_oom;
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extern int sysctl_oom_kill_allocating_task;
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extern int sysctl_oom_dump_tasks;
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extern int max_threads;
extern int core_uses_pid;
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extern int suid_dumpable;
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extern char core_pattern[];
extern int pid_max;
extern int min_free_kbytes;
extern int pid_max_min, pid_max_max;
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extern int sysctl_drop_caches;
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extern int percpu_pagelist_fraction;
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extern int compat_log;
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extern int maps_protect;
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extern int latencytop_enabled;
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extern int sysctl_nr_open_min, sysctl_nr_open_max;
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#ifdef CONFIG_RCU_TORTURE_TEST
extern int rcutorture_runnable;
#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
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/* Constants used for minimum and  maximum */
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#if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP)
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static int one = 1;
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#endif

#ifdef CONFIG_DETECT_SOFTLOCKUP
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static int sixty = 60;
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static int neg_one = -1;
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#endif

#ifdef CONFIG_MMU
static int two = 2;
#endif

static int zero;
static int one_hundred = 100;

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/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
static int minolduid;
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static int min_percpu_pagelist_fract = 8;
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static int ngroups_max = NGROUPS_MAX;

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#ifdef CONFIG_MODULES
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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

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#ifdef CONFIG_S390
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#ifdef CONFIG_MATHEMU
extern int sysctl_ieee_emulation_warnings;
#endif
extern int sysctl_userprocess_debug;
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extern int spin_retry;
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#endif

#ifdef CONFIG_BSD_PROCESS_ACCT
extern int acct_parm[];
#endif

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#ifdef CONFIG_IA64
extern int no_unaligned_warning;
#endif

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#ifdef CONFIG_RT_MUTEXES
extern int max_lock_depth;
#endif

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#ifdef CONFIG_PROC_SYSCTL
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static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
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		  void __user *buffer, size_t *lenp, loff_t *ppos);
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static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
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			       void __user *buffer, size_t *lenp, loff_t *ppos);
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#endif
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static struct ctl_table root_table[];
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static struct ctl_table_root sysctl_table_root;
static struct ctl_table_header root_table_header = {
	.ctl_table = root_table,
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	.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
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	.root = &sysctl_table_root,
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	.set = &sysctl_table_root.default_set,
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};
static struct ctl_table_root sysctl_table_root = {
	.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
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	.default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
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};
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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[];
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#ifdef CONFIG_INOTIFY_USER
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extern struct ctl_table inotify_table[];
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#endif
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#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
int sysctl_legacy_va_layout;
#endif

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extern int prove_locking;
extern int lock_stat;
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/* The default sysctl tables: */

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static struct ctl_table root_table[] = {
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	{
		.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,
	},
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/*
 * NOTE: do not add new entries to this table unless you have read
 * Documentation/sysctl/ctl_unnumbered.txt
 */
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	{ .ctl_name = 0 }
};

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#ifdef CONFIG_SCHED_DEBUG
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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 */
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#endif

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static struct ctl_table kern_table[] = {
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#ifdef CONFIG_SCHED_DEBUG
	{
		.ctl_name	= CTL_UNNUMBERED,
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		.procname	= "sched_min_granularity_ns",
		.data		= &sysctl_sched_min_granularity,
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		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
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		.proc_handler	= &sched_nr_latency_handler,
		.strategy	= &sysctl_intvec,
		.extra1		= &min_sched_granularity_ns,
		.extra2		= &max_sched_granularity_ns,
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	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "sched_latency_ns",
		.data		= &sysctl_sched_latency,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
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		.proc_handler	= &sched_nr_latency_handler,
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		.strategy	= &sysctl_intvec,
		.extra1		= &min_sched_granularity_ns,
		.extra2		= &max_sched_granularity_ns,
	},
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	{
		.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,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "sched_shares_ratelimit",
		.data		= &sysctl_sched_shares_ratelimit,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.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,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "sched_features",
		.data		= &sysctl_sched_features,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "sched_migration_cost",
		.data		= &sysctl_sched_migration_cost,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "sched_nr_migrate",
		.data		= &sysctl_sched_nr_migrate,
		.maxlen		= sizeof(unsigned int),
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		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#endif
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "sched_rt_period_us",
		.data		= &sysctl_sched_rt_period,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
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		.proc_handler	= &sched_rt_handler,
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	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "sched_rt_runtime_us",
		.data		= &sysctl_sched_rt_runtime,
		.maxlen		= sizeof(int),
		.mode		= 0644,
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		.proc_handler	= &sched_rt_handler,
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	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "sched_compat_yield",
		.data		= &sysctl_sched_compat_yield,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#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,
	},
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#endif
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	{
		.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,
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		.maxlen		= CORENAME_MAX_SIZE,
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		.mode		= 0644,
		.proc_handler	= &proc_dostring,
		.strategy	= &sysctl_string,
	},
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#ifdef CONFIG_PROC_SYSCTL
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	{
		.procname	= "tainted",
		.data		= &tainted,
		.maxlen		= sizeof(int),
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		.mode		= 0644,
		.proc_handler	= &proc_dointvec_taint,
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	},
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#endif
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#ifdef CONFIG_LATENCYTOP
	{
		.procname	= "latencytop",
		.data		= &latencytop_enabled,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
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#ifdef CONFIG_BLK_DEV_INITRD
	{
		.ctl_name	= KERN_REALROOTDEV,
		.procname	= "real-root-dev",
		.data		= &real_root_dev,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "print-fatal-signals",
		.data		= &print_fatal_signals,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#ifdef __sparc__
	{
		.ctl_name	= KERN_SPARC_REBOOT,
		.procname	= "reboot-cmd",
		.data		= reboot_command,
		.maxlen		= 256,
		.mode		= 0644,
		.proc_handler	= &proc_dostring,
		.strategy	= &sysctl_string,
	},
	{
		.ctl_name	= KERN_SPARC_STOP_A,
		.procname	= "stop-a",
		.data		= &stop_a_enabled,
		.maxlen		= sizeof (int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= KERN_SPARC_SCONS_PWROFF,
		.procname	= "scons-poweroff",
		.data		= &scons_pwroff,
		.maxlen		= sizeof (int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
#ifdef __hppa__
	{
		.ctl_name	= KERN_HPPA_PWRSW,
		.procname	= "soft-power",
		.data		= &pwrsw_enabled,
		.maxlen		= sizeof (int),
	 	.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= KERN_HPPA_UNALIGNED,
		.procname	= "unaligned-trap",
		.data		= &unaligned_enabled,
		.maxlen		= sizeof (int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
	{
		.ctl_name	= KERN_CTLALTDEL,
		.procname	= "ctrl-alt-del",
		.data		= &C_A_D,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#ifdef CONFIG_FTRACE
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "ftrace_enabled",
		.data		= &ftrace_enabled,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &ftrace_enable_sysctl,
	},
#endif
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#ifdef CONFIG_MODULES
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	{
		.ctl_name	= KERN_MODPROBE,
		.procname	= "modprobe",
		.data		= &modprobe_path,
		.maxlen		= KMOD_PATH_LEN,
		.mode		= 0644,
		.proc_handler	= &proc_dostring,
		.strategy	= &sysctl_string,
	},
#endif
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#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
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	{
		.ctl_name	= KERN_HOTPLUG,
		.procname	= "hotplug",
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		.data		= &uevent_helper,
		.maxlen		= UEVENT_HELPER_PATH_LEN,
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		.mode		= 0644,
		.proc_handler	= &proc_dostring,
		.strategy	= &sysctl_string,
	},
#endif
#ifdef CONFIG_CHR_DEV_SG
	{
		.ctl_name	= KERN_SG_BIG_BUFF,
		.procname	= "sg-big-buff",
		.data		= &sg_big_buff,
		.maxlen		= sizeof (int),
		.mode		= 0444,
		.proc_handler	= &proc_dointvec,
	},
#endif
#ifdef CONFIG_BSD_PROCESS_ACCT
	{
		.ctl_name	= KERN_ACCT,
		.procname	= "acct",
		.data		= &acct_parm,
		.maxlen		= 3*sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
#ifdef CONFIG_MAGIC_SYSRQ
	{
		.ctl_name	= KERN_SYSRQ,
		.procname	= "sysrq",
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		.data		= &__sysrq_enabled,
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		.maxlen		= sizeof (int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
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#ifdef CONFIG_PROC_SYSCTL
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	{
		.procname	= "cad_pid",
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		.data		= NULL,
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		.maxlen		= sizeof (int),
		.mode		= 0600,
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		.proc_handler	= &proc_do_cad_pid,
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	},
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#endif
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	{
		.ctl_name	= KERN_MAX_THREADS,
		.procname	= "threads-max",
		.data		= &max_threads,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= KERN_RANDOM,
		.procname	= "random",
		.mode		= 0555,
		.child		= random_table,
	},
	{
		.ctl_name	= KERN_OVERFLOWUID,
		.procname	= "overflowuid",
		.data		= &overflowuid,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= &sysctl_intvec,
		.extra1		= &minolduid,
		.extra2		= &maxolduid,
	},
	{
		.ctl_name	= KERN_OVERFLOWGID,
		.procname	= "overflowgid",
		.data		= &overflowgid,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= &sysctl_intvec,
		.extra1		= &minolduid,
		.extra2		= &maxolduid,
	},
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#ifdef CONFIG_S390
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#ifdef CONFIG_MATHEMU
	{
		.ctl_name	= KERN_IEEE_EMULATION_WARNINGS,
		.procname	= "ieee_emulation_warnings",
		.data		= &sysctl_ieee_emulation_warnings,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
	{
		.ctl_name	= KERN_S390_USER_DEBUG_LOGGING,
		.procname	= "userprocess_debug",
		.data		= &sysctl_userprocess_debug,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
	{
		.ctl_name	= KERN_PIDMAX,
		.procname	= "pid_max",
		.data		= &pid_max,
		.maxlen		= sizeof (int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= sysctl_intvec,
		.extra1		= &pid_max_min,
		.extra2		= &pid_max_max,
	},
	{
		.ctl_name	= KERN_PANIC_ON_OOPS,
		.procname	= "panic_on_oops",
		.data		= &panic_on_oops,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#if defined CONFIG_PRINTK
	{
		.ctl_name	= KERN_PRINTK,
		.procname	= "printk",
		.data		= &console_loglevel,
		.maxlen		= 4*sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= KERN_PRINTK_RATELIMIT,
		.procname	= "printk_ratelimit",
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		.data		= &printk_ratelimit_state.interval,
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		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
		.strategy	= &sysctl_jiffies,
	},
	{
		.ctl_name	= KERN_PRINTK_RATELIMIT_BURST,
		.procname	= "printk_ratelimit_burst",
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		.data		= &printk_ratelimit_state.burst,
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		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#endif
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	{
		.ctl_name	= KERN_NGROUPS_MAX,
		.procname	= "ngroups_max",
		.data		= &ngroups_max,
		.maxlen		= sizeof (int),
		.mode		= 0444,
		.proc_handler	= &proc_dointvec,
	},
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
	{
		.ctl_name       = KERN_UNKNOWN_NMI_PANIC,
		.procname       = "unknown_nmi_panic",
		.data           = &unknown_nmi_panic,
		.maxlen         = sizeof (int),
		.mode           = 0644,
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		.proc_handler   = &proc_dointvec,
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	},
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	{
		.procname       = "nmi_watchdog",
		.data           = &nmi_watchdog_enabled,
		.maxlen         = sizeof (int),
		.mode           = 0644,
		.proc_handler   = &proc_nmi_enabled,
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	},
#endif
#if defined(CONFIG_X86)
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	{
		.ctl_name	= KERN_PANIC_ON_NMI,
		.procname	= "panic_on_unrecovered_nmi",
		.data		= &panic_on_unrecovered_nmi,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= KERN_BOOTLOADER_TYPE,
		.procname	= "bootloader_type",
		.data		= &bootloader_type,
		.maxlen		= sizeof (int),
		.mode		= 0444,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "kstack_depth_to_print",
		.data		= &kstack_depth_to_print,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "io_delay_type",
		.data		= &io_delay_type,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#endif
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#if defined(CONFIG_MMU)
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	{
		.ctl_name	= KERN_RANDOMIZE,
		.procname	= "randomize_va_space",
		.data		= &randomize_va_space,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#endif
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#if defined(CONFIG_S390) && defined(CONFIG_SMP)
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	{
		.ctl_name	= KERN_SPIN_RETRY,
		.procname	= "spin_retry",
		.data		= &spin_retry,
		.maxlen		= sizeof (int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#endif
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#if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
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	{
		.procname	= "acpi_video_flags",
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		.data		= &acpi_realmode_flags,
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		.maxlen		= sizeof (unsigned long),
		.mode		= 0644,
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		.proc_handler	= &proc_doulongvec_minmax,
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	},
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#endif
#ifdef CONFIG_IA64
	{
		.ctl_name	= KERN_IA64_UNALIGNED,
		.procname	= "ignore-unaligned-usertrap",
		.data		= &no_unaligned_warning,
		.maxlen		= sizeof (int),
	 	.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#endif
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#ifdef CONFIG_DETECT_SOFTLOCKUP
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "softlockup_panic",
		.data		= &softlockup_panic,
		.maxlen		= sizeof(int),
		.mode		= 0644,
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		.proc_handler	= &proc_dointvec_minmax,
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		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
		.extra2		= &one,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "softlockup_thresh",
		.data		= &softlockup_thresh,
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		.maxlen		= sizeof(int),
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		.mode		= 0644,
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		.proc_handler	= &proc_dointvec_minmax,
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		.strategy	= &sysctl_intvec,
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		.extra1		= &neg_one,
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		.extra2		= &sixty,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "hung_task_check_count",
		.data		= &sysctl_hung_task_check_count,
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		.maxlen		= sizeof(unsigned long),
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		.mode		= 0644,
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		.proc_handler	= &proc_doulongvec_minmax,
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		.strategy	= &sysctl_intvec,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "hung_task_timeout_secs",
		.data		= &sysctl_hung_task_timeout_secs,
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		.maxlen		= sizeof(unsigned long),
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		.mode		= 0644,
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		.proc_handler	= &proc_doulongvec_minmax,
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		.strategy	= &sysctl_intvec,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "hung_task_warnings",
		.data		= &sysctl_hung_task_warnings,
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		.maxlen		= sizeof(unsigned long),
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		.mode		= 0644,
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		.proc_handler	= &proc_doulongvec_minmax,
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		.strategy	= &sysctl_intvec,
	},
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#endif
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#ifdef CONFIG_COMPAT
	{
		.ctl_name	= KERN_COMPAT_LOG,
		.procname	= "compat-log",
		.data		= &compat_log,
		.maxlen		= sizeof (int),
	 	.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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#endif
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#ifdef CONFIG_RT_MUTEXES
	{
		.ctl_name	= KERN_MAX_LOCK_DEPTH,
		.procname	= "max_lock_depth",
		.data		= &max_lock_depth,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
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#ifdef CONFIG_PROC_FS
	{
		.ctl_name       = CTL_UNNUMBERED,
		.procname       = "maps_protect",
		.data           = &maps_protect,
		.maxlen         = sizeof(int),
		.mode           = 0644,
		.proc_handler   = &proc_dointvec,
	},
#endif
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "poweroff_cmd",
		.data		= &poweroff_cmd,
		.maxlen		= POWEROFF_CMD_PATH_LEN,
		.mode		= 0644,
		.proc_handler	= &proc_dostring,
		.strategy	= &sysctl_string,
	},
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#ifdef CONFIG_KEYS
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "keys",
		.mode		= 0555,
		.child		= key_sysctls,
	},
#endif
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#ifdef CONFIG_RCU_TORTURE_TEST
	{
		.ctl_name       = CTL_UNNUMBERED,
		.procname       = "rcutorture_runnable",
		.data           = &rcutorture_runnable,
		.maxlen         = sizeof(int),
		.mode           = 0644,
		.proc_handler   = &proc_dointvec,
	},
#endif
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/*
 * NOTE: do not add new entries to this table unless you have read
 * Documentation/sysctl/ctl_unnumbered.txt
 */
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	{ .ctl_name = 0 }
};

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static struct ctl_table vm_table[] = {
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	{
		.ctl_name	= VM_OVERCOMMIT_MEMORY,
		.procname	= "overcommit_memory",
		.data		= &sysctl_overcommit_memory,
		.maxlen		= sizeof(sysctl_overcommit_memory),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= VM_PANIC_ON_OOM,
		.procname	= "panic_on_oom",
		.data		= &sysctl_panic_on_oom,
		.maxlen		= sizeof(sysctl_panic_on_oom),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "oom_kill_allocating_task",
		.data		= &sysctl_oom_kill_allocating_task,
		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "oom_dump_tasks",
		.data		= &sysctl_oom_dump_tasks,
		.maxlen		= sizeof(sysctl_oom_dump_tasks),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
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	{
		.ctl_name	= VM_OVERCOMMIT_RATIO,
		.procname	= "overcommit_ratio",
		.data		= &sysctl_overcommit_ratio,
		.maxlen		= sizeof(sysctl_overcommit_ratio),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= VM_PAGE_CLUSTER,
		.procname	= "page-cluster", 
		.data		= &page_cluster,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= VM_DIRTY_BACKGROUND,
		.procname	= "dirty_background_ratio",
		.data		= &dirty_background_ratio,
		.maxlen		= sizeof(dirty_background_ratio),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
		.extra2		= &one_hundred,
	},
	{
		.ctl_name	= VM_DIRTY_RATIO,
		.procname	= "dirty_ratio",
		.data		= &vm_dirty_ratio,
		.maxlen		= sizeof(vm_dirty_ratio),
		.mode		= 0644,
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		.proc_handler	= &dirty_ratio_handler,
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		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
		.extra2		= &one_hundred,
	},
	{
		.procname	= "dirty_writeback_centisecs",
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		.data		= &dirty_writeback_interval,
		.maxlen		= sizeof(dirty_writeback_interval),
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		.mode		= 0644,
		.proc_handler	= &dirty_writeback_centisecs_handler,
	},
	{
		.procname	= "dirty_expire_centisecs",
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		.data		= &dirty_expire_interval,
		.maxlen		= sizeof(dirty_expire_interval),
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		.mode		= 0644,
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		.proc_handler	= &proc_dointvec_userhz_jiffies,
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	},
	{
		.ctl_name	= VM_NR_PDFLUSH_THREADS,
		.procname	= "nr_pdflush_threads",
		.data		= &nr_pdflush_threads,
		.maxlen		= sizeof nr_pdflush_threads,
		.mode		= 0444 /* read-only*/,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= VM_SWAPPINESS,
		.procname	= "swappiness",
		.data		= &vm_swappiness,
		.maxlen		= sizeof(vm_swappiness),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
		.extra2		= &one_hundred,
	},
#ifdef CONFIG_HUGETLB_PAGE
	 {
		.procname	= "nr_hugepages",
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		.data		= NULL,
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		.maxlen		= sizeof(unsigned long),
		.mode		= 0644,
		.proc_handler	= &hugetlb_sysctl_handler,
		.extra1		= (void *)&hugetlb_zero,
		.extra2		= (void *)&hugetlb_infinity,
	 },
	 {
		.ctl_name	= VM_HUGETLB_GROUP,
		.procname	= "hugetlb_shm_group",
		.data		= &sysctl_hugetlb_shm_group,
		.maxlen		= sizeof(gid_t),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	 },
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	 {
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "hugepages_treat_as_movable",
		.data		= &hugepages_treat_as_movable,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &hugetlb_treat_movable_handler,
	},
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	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nr_overcommit_hugepages",
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		.data		= NULL,
		.maxlen		= sizeof(unsigned long),
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		.mode		= 0644,
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		.proc_handler	= &hugetlb_overcommit_handler,
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		.extra1		= (void *)&hugetlb_zero,
		.extra2		= (void *)&hugetlb_infinity,
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	},
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#endif
	{
		.ctl_name	= VM_LOWMEM_RESERVE_RATIO,
		.procname	= "lowmem_reserve_ratio",
		.data		= &sysctl_lowmem_reserve_ratio,
		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
		.mode		= 0644,
		.proc_handler	= &lowmem_reserve_ratio_sysctl_handler,
		.strategy	= &sysctl_intvec,
	},
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	{
		.ctl_name	= VM_DROP_PAGECACHE,
		.procname	= "drop_caches",
		.data		= &sysctl_drop_caches,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= drop_caches_sysctl_handler,
		.strategy	= &sysctl_intvec,
	},
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	{
		.ctl_name	= VM_MIN_FREE_KBYTES,
		.procname	= "min_free_kbytes",
		.data		= &min_free_kbytes,
		.maxlen		= sizeof(min_free_kbytes),
		.mode		= 0644,
		.proc_handler	= &min_free_kbytes_sysctl_handler,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
	},
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	{
		.ctl_name	= VM_PERCPU_PAGELIST_FRACTION,
		.procname	= "percpu_pagelist_fraction",
		.data		= &percpu_pagelist_fraction,
		.maxlen		= sizeof(percpu_pagelist_fraction),
		.mode		= 0644,
		.proc_handler	= &percpu_pagelist_fraction_sysctl_handler,
		.strategy	= &sysctl_intvec,
		.extra1		= &min_percpu_pagelist_fract,
	},
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#ifdef CONFIG_MMU
	{
		.ctl_name	= VM_MAX_MAP_COUNT,
		.procname	= "max_map_count",
		.data		= &sysctl_max_map_count,
		.maxlen		= sizeof(sysctl_max_map_count),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec
	},
#endif
	{
		.ctl_name	= VM_LAPTOP_MODE,
		.procname	= "laptop_mode",
		.data		= &laptop_mode,
		.maxlen		= sizeof(laptop_mode),
		.mode		= 0644,
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		.proc_handler	= &proc_dointvec_jiffies,
		.strategy	= &sysctl_jiffies,
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	},
	{
		.ctl_name	= VM_BLOCK_DUMP,
		.procname	= "block_dump",
		.data		= &block_dump,
		.maxlen		= sizeof(block_dump),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
	},
	{
		.ctl_name	= VM_VFS_CACHE_PRESSURE,
		.procname	= "vfs_cache_pressure",
		.data		= &sysctl_vfs_cache_pressure,
		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
	},
#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
	{
		.ctl_name	= VM_LEGACY_VA_LAYOUT,
		.procname	= "legacy_va_layout",
		.data		= &sysctl_legacy_va_layout,
		.maxlen		= sizeof(sysctl_legacy_va_layout),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
	},
#endif
1086 1087 1088 1089 1090 1091 1092 1093
#ifdef CONFIG_NUMA
	{
		.ctl_name	= VM_ZONE_RECLAIM_MODE,
		.procname	= "zone_reclaim_mode",
		.data		= &zone_reclaim_mode,
		.maxlen		= sizeof(zone_reclaim_mode),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
1094 1095
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
1096
	},
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107
	{
		.ctl_name	= VM_MIN_UNMAPPED,
		.procname	= "min_unmapped_ratio",
		.data		= &sysctl_min_unmapped_ratio,
		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
		.mode		= 0644,
		.proc_handler	= &sysctl_min_unmapped_ratio_sysctl_handler,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
		.extra2		= &one_hundred,
	},
1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118
	{
		.ctl_name	= VM_MIN_SLAB,
		.procname	= "min_slab_ratio",
		.data		= &sysctl_min_slab_ratio,
		.maxlen		= sizeof(sysctl_min_slab_ratio),
		.mode		= 0644,
		.proc_handler	= &sysctl_min_slab_ratio_sysctl_handler,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
		.extra2		= &one_hundred,
	},
1119
#endif
1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
#ifdef CONFIG_SMP
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "stat_interval",
		.data		= &sysctl_stat_interval,
		.maxlen		= sizeof(sysctl_stat_interval),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
		.strategy	= &sysctl_jiffies,
	},
#endif
1131 1132 1133 1134 1135 1136 1137 1138 1139
#ifdef CONFIG_SECURITY
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "mmap_min_addr",
		.data		= &mmap_min_addr,
		.maxlen         = sizeof(unsigned long),
		.mode		= 0644,
		.proc_handler	= &proc_doulongvec_minmax,
	},
1140
#endif
1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151
#ifdef CONFIG_NUMA
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "numa_zonelist_order",
		.data		= &numa_zonelist_order,
		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
		.mode		= 0644,
		.proc_handler	= &numa_zonelist_order_handler,
		.strategy	= &sysctl_string,
	},
#endif
1152
#if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1153
   (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1154 1155 1156 1157 1158 1159 1160 1161 1162 1163
	{
		.ctl_name	= VM_VDSO_ENABLED,
		.procname	= "vdso_enabled",
		.data		= &vdso_enabled,
		.maxlen		= sizeof(vdso_enabled),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
	},
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#endif
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
#ifdef CONFIG_HIGHMEM
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "highmem_is_dirtyable",
		.data		= &vm_highmem_is_dirtyable,
		.maxlen		= sizeof(vm_highmem_is_dirtyable),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
		.extra2		= &one,
	},
#endif
1178 1179 1180 1181
/*
 * NOTE: do not add new entries to this table unless you have read
 * Documentation/sysctl/ctl_unnumbered.txt
 */
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	{ .ctl_name = 0 }
};

1185
#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1186
static struct ctl_table binfmt_misc_table[] = {
1187 1188 1189 1190
	{ .ctl_name = 0 }
};
#endif

1191
static struct ctl_table fs_table[] = {
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	{
		.ctl_name	= FS_NRINODE,
		.procname	= "inode-nr",
		.data		= &inodes_stat,
		.maxlen		= 2*sizeof(int),
		.mode		= 0444,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= FS_STATINODE,
		.procname	= "inode-state",
		.data		= &inodes_stat,
		.maxlen		= 7*sizeof(int),
		.mode		= 0444,
		.proc_handler	= &proc_dointvec,
	},
	{
		.procname	= "file-nr",
		.data		= &files_stat,
		.maxlen		= 3*sizeof(int),
		.mode		= 0444,
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		.proc_handler	= &proc_nr_files,
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	},
	{
		.ctl_name	= FS_MAXFILE,
		.procname	= "file-max",
		.data		= &files_stat.max_files,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
1223 1224 1225 1226 1227 1228
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nr_open",
		.data		= &sysctl_nr_open,
		.maxlen		= sizeof(int),
		.mode		= 0644,
1229 1230 1231
		.proc_handler	= &proc_dointvec_minmax,
		.extra1		= &sysctl_nr_open_min,
		.extra2		= &sysctl_nr_open_max,
1232
	},
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	{
		.ctl_name	= FS_DENTRY,
		.procname	= "dentry-state",
		.data		= &dentry_stat,
		.maxlen		= 6*sizeof(int),
		.mode		= 0444,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= FS_OVERFLOWUID,
		.procname	= "overflowuid",
		.data		= &fs_overflowuid,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= &sysctl_intvec,
		.extra1		= &minolduid,
		.extra2		= &maxolduid,
	},
	{
		.ctl_name	= FS_OVERFLOWGID,
		.procname	= "overflowgid",
		.data		= &fs_overflowgid,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= &sysctl_intvec,
		.extra1		= &minolduid,
		.extra2		= &maxolduid,
	},
	{
		.ctl_name	= FS_LEASES,
		.procname	= "leases-enable",
		.data		= &leases_enable,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#ifdef CONFIG_DNOTIFY
	{
		.ctl_name	= FS_DIR_NOTIFY,
		.procname	= "dir-notify-enable",
		.data		= &dir_notify_enable,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
#endif
#ifdef CONFIG_MMU
	{
		.ctl_name	= FS_LEASE_TIME,
		.procname	= "lease-break-time",
		.data		= &lease_break_time,
		.maxlen		= sizeof(int),
		.mode		= 0644,
1288 1289 1290 1291
		.proc_handler	= &proc_dointvec_minmax,
		.strategy	= &sysctl_intvec,
		.extra1		= &zero,
		.extra2		= &two,
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	},
	{
		.procname	= "aio-nr",
		.data		= &aio_nr,
		.maxlen		= sizeof(aio_nr),
		.mode		= 0444,
1298
		.proc_handler	= &proc_doulongvec_minmax,
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	},
	{
		.procname	= "aio-max-nr",
		.data		= &aio_max_nr,
		.maxlen		= sizeof(aio_max_nr),
		.mode		= 0644,
1305
		.proc_handler	= &proc_doulongvec_minmax,
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	},
1307
#ifdef CONFIG_INOTIFY_USER
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	{
		.ctl_name	= FS_INOTIFY,
		.procname	= "inotify",
		.mode		= 0555,
		.child		= inotify_table,
	},
#endif	
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#endif
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	{
		.ctl_name	= KERN_SETUID_DUMPABLE,
		.procname	= "suid_dumpable",
		.data		= &suid_dumpable,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
1324 1325 1326 1327 1328 1329 1330 1331
#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "binfmt_misc",
		.mode		= 0555,
		.child		= binfmt_misc_table,
	},
#endif
1332 1333 1334 1335
/*
 * NOTE: do not add new entries to this table unless you have read
 * Documentation/sysctl/ctl_unnumbered.txt
 */
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	{ .ctl_name = 0 }
};

1339
static struct ctl_table debug_table[] = {
1340
#if defined(CONFIG_X86) || defined(CONFIG_PPC)
1341 1342 1343 1344 1345 1346 1347 1348 1349
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "exception-trace",
		.data		= &show_unhandled_signals,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec
	},
#endif
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	{ .ctl_name = 0 }
};

1353
static struct ctl_table dev_table[] = {
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	{ .ctl_name = 0 }
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};
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1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397
static DEFINE_SPINLOCK(sysctl_lock);

/* called under sysctl_lock */
static int use_table(struct ctl_table_header *p)
{
	if (unlikely(p->unregistering))
		return 0;
	p->used++;
	return 1;
}

/* called under sysctl_lock */
static void unuse_table(struct ctl_table_header *p)
{
	if (!--p->used)
		if (unlikely(p->unregistering))
			complete(p->unregistering);
}

/* called under sysctl_lock, will reacquire if has to wait */
static void start_unregistering(struct ctl_table_header *p)
{
	/*
	 * if p->used is 0, nobody will ever touch that entry again;
	 * we'll eliminate all paths to it before dropping sysctl_lock
	 */
	if (unlikely(p->used)) {
		struct completion wait;
		init_completion(&wait);
		p->unregistering = &wait;
		spin_unlock(&sysctl_lock);
		wait_for_completion(&wait);
		spin_lock(&sysctl_lock);
	}
	/*
	 * do not remove from the list until nobody holds it; walking the
	 * list in do_sysctl() relies on that.
	 */
	list_del_init(&p->ctl_entry);
}

1398 1399 1400 1401 1402 1403 1404 1405 1406
void sysctl_head_finish(struct ctl_table_header *head)
{
	if (!head)
		return;
	spin_lock(&sysctl_lock);
	unuse_table(head);
	spin_unlock(&sysctl_lock);
}

1407 1408 1409 1410 1411 1412 1413 1414 1415
static struct ctl_table_set *
lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
{
	struct ctl_table_set *set = &root->default_set;
	if (root->lookup)
		set = root->lookup(root, namespaces);
	return set;
}

1416 1417
static struct list_head *
lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1418
{
1419 1420
	struct ctl_table_set *set = lookup_header_set(root, namespaces);
	return &set->list;
1421 1422 1423 1424 1425 1426 1427
}

struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
					    struct ctl_table_header *prev)
{
	struct ctl_table_root *root;
	struct list_head *header_list;
1428 1429
	struct ctl_table_header *head;
	struct list_head *tmp;
1430

1431 1432
	spin_lock(&sysctl_lock);
	if (prev) {
1433
		head = prev;
1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446
		tmp = &prev->ctl_entry;
		unuse_table(prev);
		goto next;
	}
	tmp = &root_table_header.ctl_entry;
	for (;;) {
		head = list_entry(tmp, struct ctl_table_header, ctl_entry);

		if (!use_table(head))
			goto next;
		spin_unlock(&sysctl_lock);
		return head;
	next:
1447
		root = head->root;
1448
		tmp = tmp->next;
1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460
		header_list = lookup_header_list(root, namespaces);
		if (tmp != header_list)
			continue;

		do {
			root = list_entry(root->root_list.next,
					struct ctl_table_root, root_list);
			if (root == &sysctl_table_root)
				goto out;
			header_list = lookup_header_list(root, namespaces);
		} while (list_empty(header_list));
		tmp = header_list->next;
1461
	}
1462
out:
1463 1464 1465 1466
	spin_unlock(&sysctl_lock);
	return NULL;
}

1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478
struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
{
	return __sysctl_head_next(current->nsproxy, prev);
}

void register_sysctl_root(struct ctl_table_root *root)
{
	spin_lock(&sysctl_lock);
	list_add_tail(&root->root_list, &sysctl_table_root.root_list);
	spin_unlock(&sysctl_lock);
}

1479
#ifdef CONFIG_SYSCTL_SYSCALL
1480
/* Perform the actual read/write of a sysctl table entry. */
1481 1482
static int do_sysctl_strategy(struct ctl_table_root *root,
			struct ctl_table *table,
1483 1484 1485 1486 1487 1488 1489 1490 1491 1492
			int __user *name, int nlen,
			void __user *oldval, size_t __user *oldlenp,
			void __user *newval, size_t newlen)
{
	int op = 0, rc;

	if (oldval)
		op |= 004;
	if (newval)
		op |= 002;
1493
	if (sysctl_perm(root, table, op))
1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518
		return -EPERM;

	if (table->strategy) {
		rc = table->strategy(table, name, nlen, oldval, oldlenp,
				     newval, newlen);
		if (rc < 0)
			return rc;
		if (rc > 0)
			return 0;
	}

	/* If there is no strategy routine, or if the strategy returns
	 * zero, proceed with automatic r/w */
	if (table->data && table->maxlen) {
		rc = sysctl_data(table, name, nlen, oldval, oldlenp,
				 newval, newlen);
		if (rc < 0)
			return rc;
	}
	return 0;
}

static int parse_table(int __user *name, int nlen,
		       void __user *oldval, size_t __user *oldlenp,
		       void __user *newval, size_t newlen,
1519
		       struct ctl_table_root *root,
1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533
		       struct ctl_table *table)
{
	int n;
repeat:
	if (!nlen)
		return -ENOTDIR;
	if (get_user(n, name))
		return -EFAULT;
	for ( ; table->ctl_name || table->procname; table++) {
		if (!table->ctl_name)
			continue;
		if (n == table->ctl_name) {
			int error;
			if (table->child) {
1534
				if (sysctl_perm(root, table, 001))
1535 1536 1537 1538 1539 1540
					return -EPERM;
				name++;
				nlen--;
				table = table->child;
				goto repeat;
			}
1541
			error = do_sysctl_strategy(root, table, name, nlen,
1542 1543 1544 1545 1546 1547 1548 1549
						   oldval, oldlenp,
						   newval, newlen);
			return error;
		}
	}
	return -ENOTDIR;
}

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int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
	       void __user *newval, size_t newlen)
{
1553
	struct ctl_table_header *head;
1554
	int error = -ENOTDIR;
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	if (nlen <= 0 || nlen >= CTL_MAXNAME)
		return -ENOTDIR;
	if (oldval) {
		int old_len;
		if (!oldlenp || get_user(old_len, oldlenp))
			return -EFAULT;
	}
1563

1564 1565
	for (head = sysctl_head_next(NULL); head;
			head = sysctl_head_next(head)) {
1566
		error = parse_table(name, nlen, oldval, oldlenp, 
1567 1568
					newval, newlen,
					head->root, head->ctl_table);
1569 1570
		if (error != -ENOTDIR) {
			sysctl_head_finish(head);
1571
			break;
1572 1573
		}
	}
1574
	return error;
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}

asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
{
	struct __sysctl_args tmp;
	int error;

	if (copy_from_user(&tmp, args, sizeof(tmp)))
		return -EFAULT;

1585 1586 1587 1588
	error = deprecated_sysctl_warning(&tmp);
	if (error)
		goto out;

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	lock_kernel();
	error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
			  tmp.newval, tmp.newlen);
	unlock_kernel();
1593
out:
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	return error;
}
1596
#endif /* CONFIG_SYSCTL_SYSCALL */
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/*
1599
 * sysctl_perm does NOT grant the superuser all rights automatically, because
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 * some sysctl variables are readonly even to root.
 */

static int test_perm(int mode, int op)
{
	if (!current->euid)
		mode >>= 6;
	else if (in_egroup_p(0))
		mode >>= 3;
	if ((mode & op & 0007) == op)
		return 0;
	return -EACCES;
}

1614
int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
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{
	int error;
1617 1618
	int mode;

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	error = security_sysctl(table, op);
	if (error)
		return error;
1622 1623 1624 1625 1626 1627 1628

	if (root->permissions)
		mode = root->permissions(root, current->nsproxy, table);
	else
		mode = table->mode;

	return test_perm(mode, op);
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}

1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642
static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
{
	for (; table->ctl_name || table->procname; table++) {
		table->parent = parent;
		if (table->child)
			sysctl_set_parent(table, table->child);
	}
}

static __init int sysctl_init(void)
{
	sysctl_set_parent(NULL, root_table);
1643 1644 1645 1646 1647 1648
#ifdef CONFIG_SYSCTL_SYSCALL_CHECK
	{
		int err;
		err = sysctl_check_table(current->nsproxy, root_table);
	}
#endif
1649 1650 1651 1652 1653
	return 0;
}

core_initcall(sysctl_init);

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/**
1655 1656 1657
 * __register_sysctl_paths - register a sysctl hierarchy
 * @root: List of sysctl headers to register on
 * @namespaces: Data to compute which lists of sysctl entries are visible
1658
 * @path: The path to the directory the sysctl table is in.
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 * @table: the top-level table structure
 *
 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1662
 * array. A completely 0 filled entry terminates the table.
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 *
1664
 * The members of the &struct ctl_table structure are used as follows:
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 *
 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
 *            must be unique within that level of sysctl
 *
 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
 *            enter a sysctl file
 *
 * data - a pointer to data for use by proc_handler
 *
 * maxlen - the maximum size in bytes of the data
 *
 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
 *
 * child - a pointer to the child sysctl table if this entry is a directory, or
 *         %NULL.
 *
 * proc_handler - the text handler routine (described below)
 *
 * strategy - the strategy routine (described below)
 *
 * de - for internal use by the sysctl routines
 *
 * extra1, extra2 - extra pointers usable by the proc handler routines
 *
 * Leaf nodes in the sysctl tree will be represented by a single file
 * under /proc; non-leaf nodes will be represented by directories.
 *
 * sysctl(2) can automatically manage read and write requests through
 * the sysctl table.  The data and maxlen fields of the ctl_table
 * struct enable minimal validation of the values being written to be
 * performed, and the mode field allows minimal authentication.
 *
 * More sophisticated management can be enabled by the provision of a
 * strategy routine with the table entry.  This will be called before
 * any automatic read or write of the data is performed.
 *
 * The strategy routine may return
 *
 * < 0 - Error occurred (error is passed to user process)
 *
 * 0   - OK - proceed with automatic read or write.
 *
 * > 0 - OK - read or write has been done by the strategy routine, so
 *       return immediately.
 *
 * There must be a proc_handler routine for any terminal nodes
 * mirrored under /proc/sys (non-terminals are handled by a built-in
 * directory handler).  Several default handlers are available to
 * cover common cases -
 *
 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 
 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
 *
 * It is the handler's job to read the input buffer from user memory
 * and process it. The handler should return 0 on success.
 *
 * This routine returns %NULL on a failure to register, and a pointer
 * to the table header on success.
 */
1725 1726 1727 1728
struct ctl_table_header *__register_sysctl_paths(
	struct ctl_table_root *root,
	struct nsproxy *namespaces,
	const struct ctl_path *path, struct ctl_table *table)
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{
1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748
	struct ctl_table_header *header;
	struct ctl_table *new, **prevp;
	unsigned int n, npath;

	/* Count the path components */
	for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
		;

	/*
	 * For each path component, allocate a 2-element ctl_table array.
	 * The first array element will be filled with the sysctl entry
	 * for this, the second will be the sentinel (ctl_name == 0).
	 *
	 * We allocate everything in one go so that we don't have to
	 * worry about freeing additional memory in unregister_sysctl_table.
	 */
	header = kzalloc(sizeof(struct ctl_table_header) +
			 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
	if (!header)
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		return NULL;
1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766

	new = (struct ctl_table *) (header + 1);

	/* Now connect the dots */
	prevp = &header->ctl_table;
	for (n = 0; n < npath; ++n, ++path) {
		/* Copy the procname */
		new->procname = path->procname;
		new->ctl_name = path->ctl_name;
		new->mode     = 0555;

		*prevp = new;
		prevp = &new->child;

		new += 2;
	}
	*prevp = table;
1767
	header->ctl_table_arg = table;
1768 1769 1770 1771

	INIT_LIST_HEAD(&header->ctl_entry);
	header->used = 0;
	header->unregistering = NULL;
1772
	header->root = root;
1773
	sysctl_set_parent(NULL, header->ctl_table);
1774
#ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1775
	if (sysctl_check_table(namespaces, header->ctl_table)) {
1776
		kfree(header);
1777 1778
		return NULL;
	}
1779
#endif
1780
	spin_lock(&sysctl_lock);
1781 1782
	header->set = lookup_header_set(root, namespaces);
	list_add_tail(&header->ctl_entry, &header->set->list);
1783
	spin_unlock(&sysctl_lock);
1784 1785 1786 1787

	return header;
}

1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804
/**
 * register_sysctl_table_path - register a sysctl table hierarchy
 * @path: The path to the directory the sysctl table is in.
 * @table: the top-level table structure
 *
 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
 * array. A completely 0 filled entry terminates the table.
 *
 * See __register_sysctl_paths for more details.
 */
struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
						struct ctl_table *table)
{
	return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
					path, table);
}

1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818
/**
 * register_sysctl_table - register a sysctl table hierarchy
 * @table: the top-level table structure
 *
 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
 * array. A completely 0 filled entry terminates the table.
 *
 * See register_sysctl_paths for more details.
 */
struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
{
	static const struct ctl_path null_path[] = { {} };

	return register_sysctl_paths(null_path, table);
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}

/**
 * unregister_sysctl_table - unregister a sysctl table hierarchy
 * @header: the header returned from register_sysctl_table
 *
 * Unregisters the sysctl table and all children. proc entries may not
 * actually be removed until they are no longer used by anyone.
 */
void unregister_sysctl_table(struct ctl_table_header * header)
{
1830
	might_sleep();
1831 1832 1833 1834

	if (header == NULL)
		return;

1835 1836 1837
	spin_lock(&sysctl_lock);
	start_unregistering(header);
	spin_unlock(&sysctl_lock);
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	kfree(header);
}

1841 1842 1843 1844 1845 1846 1847 1848 1849
void setup_sysctl_set(struct ctl_table_set *p,
	struct ctl_table_set *parent,
	int (*is_seen)(struct ctl_table_set *))
{
	INIT_LIST_HEAD(&p->list);
	p->parent = parent ? parent : &sysctl_table_root.default_set;
	p->is_seen = is_seen;
}

1850
#else /* !CONFIG_SYSCTL */
1851
struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1852 1853 1854 1855
{
	return NULL;
}

1856 1857 1858 1859 1860 1861
struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
						    struct ctl_table *table)
{
	return NULL;
}

1862 1863 1864 1865
void unregister_sysctl_table(struct ctl_table_header * table)
{
}

1866 1867 1868 1869 1870 1871
void setup_sysctl_set(struct ctl_table_set *p,
	struct ctl_table_set *parent,
	int (*is_seen)(struct ctl_table_set *))
{
}

1872 1873
#endif /* CONFIG_SYSCTL */

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/*
 * /proc/sys support
 */

1878
#ifdef CONFIG_PROC_SYSCTL
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1880 1881 1882
static int _proc_do_string(void* data, int maxlen, int write,
			   struct file *filp, void __user *buffer,
			   size_t *lenp, loff_t *ppos)
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{
	size_t len;
	char __user *p;
	char c;
1887 1888

	if (!data || !maxlen || !*lenp) {
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		*lenp = 0;
		return 0;
	}
1892

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	if (write) {
		len = 0;
		p = buffer;
		while (len < *lenp) {
			if (get_user(c, p++))
				return -EFAULT;
			if (c == 0 || c == '\n')
				break;
			len++;
		}
1903 1904 1905
		if (len >= maxlen)
			len = maxlen-1;
		if(copy_from_user(data, buffer, len))
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			return -EFAULT;
1907
		((char *) data)[len] = 0;
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		*ppos += *lenp;
	} else {
1910 1911 1912
		len = strlen(data);
		if (len > maxlen)
			len = maxlen;
1913 1914 1915 1916 1917 1918 1919 1920 1921

		if (*ppos > len) {
			*lenp = 0;
			return 0;
		}

		data += *ppos;
		len  -= *ppos;

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		if (len > *lenp)
			len = *lenp;
		if (len)
1925
			if(copy_to_user(buffer, data, len))
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				return -EFAULT;
		if (len < *lenp) {
			if(put_user('\n', ((char __user *) buffer) + len))
				return -EFAULT;
			len++;
		}
		*lenp = len;
		*ppos += len;
	}
	return 0;
}

1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955
/**
 * proc_dostring - read a string sysctl
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes a string from/to the user buffer. If the kernel
 * buffer provided is not large enough to hold the string, the
 * string is truncated. The copied string is %NULL-terminated.
 * If the string is being read by the user process, it is copied
 * and a newline '\n' is added. It is truncated if the buffer is
 * not large enough.
 *
 * Returns 0 on success.
 */
1956
int proc_dostring(struct ctl_table *table, int write, struct file *filp,
1957 1958 1959 1960 1961 1962
		  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return _proc_do_string(table->data, table->maxlen, write, filp,
			       buffer, lenp, ppos);
}

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static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
				 int *valp,
				 int write, void *data)
{
	if (write) {
		*valp = *negp ? -*lvalp : *lvalp;
	} else {
		int val = *valp;
		if (val < 0) {
			*negp = -1;
			*lvalp = (unsigned long)-val;
		} else {
			*negp = 0;
			*lvalp = (unsigned long)val;
		}
	}
	return 0;
}

1983
static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
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		  int write, struct file *filp, void __user *buffer,
		  size_t *lenp, loff_t *ppos,
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		  int (*conv)(int *negp, unsigned long *lvalp, int *valp,
			      int write, void *data),
		  void *data)
{
#define TMPBUFLEN 21
	int *i, vleft, first=1, neg, val;
	unsigned long lval;
	size_t left, len;
	
	char buf[TMPBUFLEN], *p;
	char __user *s = buffer;
	
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	if (!tbl_data || !table->maxlen || !*lenp ||
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	    (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}
	
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	i = (int *) tbl_data;
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	vleft = table->maxlen / sizeof(*i);
	left = *lenp;

	if (!conv)
		conv = do_proc_dointvec_conv;

	for (; left && vleft--; i++, first=0) {
		if (write) {
			while (left) {
				char c;
				if (get_user(c, s))
					return -EFAULT;
				if (!isspace(c))
					break;
				left--;
				s++;
			}
			if (!left)
				break;
			neg = 0;
			len = left;
			if (len > sizeof(buf) - 1)
				len = sizeof(buf) - 1;
			if (copy_from_user(buf, s, len))
				return -EFAULT;
			buf[len] = 0;
			p = buf;
			if (*p == '-' && left > 1) {
				neg = 1;
2034
				p++;
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			}
			if (*p < '0' || *p > '9')
				break;

			lval = simple_strtoul(p, &p, 0);

			len = p-buf;
			if ((len < left) && *p && !isspace(*p))
				break;
			if (neg)
				val = -val;
			s += len;
			left -= len;

			if (conv(&neg, &lval, i, 1, data))
				break;
		} else {
			p = buf;
			if (!first)
				*p++ = '\t';
	
			if (conv(&neg, &lval, i, 0, data))
				break;

			sprintf(p, "%s%lu", neg ? "-" : "", lval);
			len = strlen(buf);
			if (len > left)
				len = left;
			if(copy_to_user(s, buf, len))
				return -EFAULT;
			left -= len;
			s += len;
		}
	}

	if (!write && !first && left) {
		if(put_user('\n', s))
			return -EFAULT;
		left--, s++;
	}
	if (write) {
		while (left) {
			char c;
			if (get_user(c, s++))
				return -EFAULT;
			if (!isspace(c))
				break;
			left--;
		}
	}
	if (write && first)
		return -EINVAL;
	*lenp -= left;
	*ppos += *lenp;
	return 0;
#undef TMPBUFLEN
}

2093
static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
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		  void __user *buffer, size_t *lenp, loff_t *ppos,
		  int (*conv)(int *negp, unsigned long *lvalp, int *valp,
			      int write, void *data),
		  void *data)
{
	return __do_proc_dointvec(table->data, table, write, filp,
			buffer, lenp, ppos, conv, data);
}

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/**
 * proc_dointvec - read a vector of integers
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string. 
 *
 * Returns 0 on success.
 */
2117
int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
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		     void __user *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
		    	    NULL,NULL);
}

#define OP_SET	0
#define OP_AND	1
2126
#define OP_OR	2
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static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
				      int *valp,
				      int write, void *data)
{
	int op = *(int *)data;
	if (write) {
		int val = *negp ? -*lvalp : *lvalp;
		switch(op) {
		case OP_SET:	*valp = val; break;
		case OP_AND:	*valp &= val; break;
2138
		case OP_OR:	*valp |= val; break;
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		}
	} else {
		int val = *valp;
		if (val < 0) {
			*negp = -1;
			*lvalp = (unsigned long)-val;
		} else {
			*negp = 0;
			*lvalp = (unsigned long)val;
		}
	}
	return 0;
}

2153 2154 2155
/*
 *	Taint values can only be increased
 */
2156
static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
2157 2158 2159 2160
			       void __user *buffer, size_t *lenp, loff_t *ppos)
{
	int op;

2161
	if (write && !capable(CAP_SYS_ADMIN))
2162 2163 2164 2165 2166 2167 2168
		return -EPERM;

	op = OP_OR;
	return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
				do_proc_dointvec_bset_conv,&op);
}

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struct do_proc_dointvec_minmax_conv_param {
	int *min;
	int *max;
};

static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, 
					int *valp, 
					int write, void *data)
{
	struct do_proc_dointvec_minmax_conv_param *param = data;
	if (write) {
		int val = *negp ? -*lvalp : *lvalp;
		if ((param->min && *param->min > val) ||
		    (param->max && *param->max < val))
			return -EINVAL;
		*valp = val;
	} else {
		int val = *valp;
		if (val < 0) {
			*negp = -1;
			*lvalp = (unsigned long)-val;
		} else {
			*negp = 0;
			*lvalp = (unsigned long)val;
		}
	}
	return 0;
}

/**
 * proc_dointvec_minmax - read a vector of integers with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success.
 */
2215
int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
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		  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct do_proc_dointvec_minmax_conv_param param = {
		.min = (int *) table->extra1,
		.max = (int *) table->extra2,
	};
	return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
				do_proc_dointvec_minmax_conv, &param);
}

2226
static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
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				     struct file *filp,
				     void __user *buffer,
				     size_t *lenp, loff_t *ppos,
				     unsigned long convmul,
				     unsigned long convdiv)
{
#define TMPBUFLEN 21
	unsigned long *i, *min, *max, val;
	int vleft, first=1, neg;
	size_t len, left;
	char buf[TMPBUFLEN], *p;
	char __user *s = buffer;
	
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	if (!data || !table->maxlen || !*lenp ||
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	    (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}
	
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	i = (unsigned long *) data;
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	min = (unsigned long *) table->extra1;
	max = (unsigned long *) table->extra2;
	vleft = table->maxlen / sizeof(unsigned long);
	left = *lenp;
	
	for (; left && vleft--; i++, min++, max++, first=0) {
		if (write) {
			while (left) {
				char c;
				if (get_user(c, s))
					return -EFAULT;
				if (!isspace(c))
					break;
				left--;
				s++;
			}
			if (!left)
				break;
			neg = 0;
			len = left;
			if (len > TMPBUFLEN-1)
				len = TMPBUFLEN-1;
			if (copy_from_user(buf, s, len))
				return -EFAULT;
			buf[len] = 0;
			p = buf;
			if (*p == '-' && left > 1) {
				neg = 1;
2275
				p++;
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			}
			if (*p < '0' || *p > '9')
				break;
			val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
			len = p-buf;
			if ((len < left) && *p && !isspace(*p))
				break;
			if (neg)
				val = -val;
			s += len;
			left -= len;

			if(neg)
				continue;
			if ((min && val < *min) || (max && val > *max))
				continue;
			*i = val;
		} else {
			p = buf;
			if (!first)
				*p++ = '\t';
			sprintf(p, "%lu", convdiv * (*i) / convmul);
			len = strlen(buf);
			if (len > left)
				len = left;
			if(copy_to_user(s, buf, len))
				return -EFAULT;
			left -= len;
			s += len;
		}
	}

	if (!write && !first && left) {
		if(put_user('\n', s))
			return -EFAULT;
		left--, s++;
	}
	if (write) {
		while (left) {
			char c;
			if (get_user(c, s++))
				return -EFAULT;
			if (!isspace(c))
				break;
			left--;
		}
	}
	if (write && first)
		return -EINVAL;
	*lenp -= left;
	*ppos += *lenp;
	return 0;
#undef TMPBUFLEN
}

2331
static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
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				     struct file *filp,
				     void __user *buffer,
				     size_t *lenp, loff_t *ppos,
				     unsigned long convmul,
				     unsigned long convdiv)
{
	return __do_proc_doulongvec_minmax(table->data, table, write,
			filp, buffer, lenp, ppos, convmul, convdiv);
}

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/**
 * proc_doulongvec_minmax - read a vector of long integers with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
 * values from/to the user buffer, treated as an ASCII string.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success.
 */
2359
int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
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			   void __user *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
}

/**
 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
 * values from/to the user buffer, treated as an ASCII string. The values
 * are treated as milliseconds, and converted to jiffies when they are stored.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success.
 */
2383
int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
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				      struct file *filp,
				      void __user *buffer,
				      size_t *lenp, loff_t *ppos)
{
    return do_proc_doulongvec_minmax(table, write, filp, buffer,
				     lenp, ppos, HZ, 1000l);
}


static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
					 int *valp,
					 int write, void *data)
{
	if (write) {
2398 2399
		if (*lvalp > LONG_MAX / HZ)
			return 1;
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		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
	} else {
		int val = *valp;
		unsigned long lval;
		if (val < 0) {
			*negp = -1;
			lval = (unsigned long)-val;
		} else {
			*negp = 0;
			lval = (unsigned long)val;
		}
		*lvalp = lval / HZ;
	}
	return 0;
}

static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
						int *valp,
						int write, void *data)
{
	if (write) {
2421 2422
		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
			return 1;
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		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
	} else {
		int val = *valp;
		unsigned long lval;
		if (val < 0) {
			*negp = -1;
			lval = (unsigned long)-val;
		} else {
			*negp = 0;
			lval = (unsigned long)val;
		}
		*lvalp = jiffies_to_clock_t(lval);
	}
	return 0;
}

static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
					    int *valp,
					    int write, void *data)
{
	if (write) {
		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
	} else {
		int val = *valp;
		unsigned long lval;
		if (val < 0) {
			*negp = -1;
			lval = (unsigned long)-val;
		} else {
			*negp = 0;
			lval = (unsigned long)val;
		}
		*lvalp = jiffies_to_msecs(lval);
	}
	return 0;
}

/**
 * proc_dointvec_jiffies - read a vector of integers as seconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string. 
 * The values read are assumed to be in seconds, and are converted into
 * jiffies.
 *
 * Returns 0 on success.
 */
2476
int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
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			  void __user *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
		    	    do_proc_dointvec_jiffies_conv,NULL);
}

/**
 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
2490
 * @ppos: pointer to the file position
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 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string. 
 * The values read are assumed to be in 1/USER_HZ seconds, and 
 * are converted into jiffies.
 *
 * Returns 0 on success.
 */
2499
int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
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				 void __user *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
}

/**
 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @filp: the file structure
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
2513 2514
 * @ppos: file position
 * @ppos: the current position in the file
L
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 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string. 
 * The values read are assumed to be in 1/1000 seconds, and 
 * are converted into jiffies.
 *
 * Returns 0 on success.
 */
2523
int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
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			     void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
				do_proc_dointvec_ms_jiffies_conv, NULL);
}

2530
static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2531 2532 2533 2534 2535 2536
			   void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct pid *new_pid;
	pid_t tmp;
	int r;

2537
	tmp = pid_vnr(cad_pid);
2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551

	r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
			       lenp, ppos, NULL, NULL);
	if (r || !write)
		return r;

	new_pid = find_get_pid(tmp);
	if (!new_pid)
		return -ESRCH;

	put_pid(xchg(&cad_pid, new_pid));
	return 0;
}

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#else /* CONFIG_PROC_FS */

2554
int proc_dostring(struct ctl_table *table, int write, struct file *filp,
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		  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

2560
int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
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		  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

2566
int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
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		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

2572
int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
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		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

2578
int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
L
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		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

2584
int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
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			     void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

2590
int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
L
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2591 2592 2593 2594 2595
		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return -ENOSYS;
}

2596
int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
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				      struct file *filp,
				      void __user *buffer,
				      size_t *lenp, loff_t *ppos)
{
    return -ENOSYS;
}


#endif /* CONFIG_PROC_FS */


2608
#ifdef CONFIG_SYSCTL_SYSCALL
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/*
 * General sysctl support routines 
 */

2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646
/* The generic sysctl data routine (used if no strategy routine supplied) */
int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
		void __user *oldval, size_t __user *oldlenp,
		void __user *newval, size_t newlen)
{
	size_t len;

	/* Get out of I don't have a variable */
	if (!table->data || !table->maxlen)
		return -ENOTDIR;

	if (oldval && oldlenp) {
		if (get_user(len, oldlenp))
			return -EFAULT;
		if (len) {
			if (len > table->maxlen)
				len = table->maxlen;
			if (copy_to_user(oldval, table->data, len))
				return -EFAULT;
			if (put_user(len, oldlenp))
				return -EFAULT;
		}
	}

	if (newval && newlen) {
		if (newlen > table->maxlen)
			newlen = table->maxlen;

		if (copy_from_user(table->data, newval, newlen))
			return -EFAULT;
	}
	return 1;
}

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/* The generic string strategy routine: */
2648
int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
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2649
		  void __user *oldval, size_t __user *oldlenp,
2650
		  void __user *newval, size_t newlen)
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{
	if (!table->data || !table->maxlen) 
		return -ENOTDIR;
	
	if (oldval && oldlenp) {
2656 2657
		size_t bufsize;
		if (get_user(bufsize, oldlenp))
L
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			return -EFAULT;
2659 2660 2661 2662 2663
		if (bufsize) {
			size_t len = strlen(table->data), copied;

			/* This shouldn't trigger for a well-formed sysctl */
			if (len > table->maxlen)
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2664
				len = table->maxlen;
2665 2666 2667 2668 2669 2670

			/* Copy up to a max of bufsize-1 bytes of the string */
			copied = (len >= bufsize) ? bufsize - 1 : len;

			if (copy_to_user(oldval, table->data, copied) ||
			    put_user(0, (char __user *)(oldval + copied)))
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2671
				return -EFAULT;
2672
			if (put_user(len, oldlenp))
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				return -EFAULT;
		}
	}
	if (newval && newlen) {
2677
		size_t len = newlen;
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		if (len > table->maxlen)
			len = table->maxlen;
		if(copy_from_user(table->data, newval, len))
			return -EFAULT;
		if (len == table->maxlen)
			len--;
		((char *) table->data)[len] = 0;
	}
2686
	return 1;
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}

/*
 * This function makes sure that all of the integers in the vector
 * are between the minimum and maximum values given in the arrays
 * table->extra1 and table->extra2, respectively.
 */
2694
int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
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2695
		void __user *oldval, size_t __user *oldlenp,
2696
		void __user *newval, size_t newlen)
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{

	if (newval && newlen) {
		int __user *vec = (int __user *) newval;
		int *min = (int *) table->extra1;
		int *max = (int *) table->extra2;
		size_t length;
		int i;

		if (newlen % sizeof(int) != 0)
			return -EINVAL;

		if (!table->extra1 && !table->extra2)
			return 0;

		if (newlen > table->maxlen)
			newlen = table->maxlen;
		length = newlen / sizeof(int);

		for (i = 0; i < length; i++) {
			int value;
			if (get_user(value, vec + i))
				return -EFAULT;
			if (min && value < min[i])
				return -EINVAL;
			if (max && value > max[i])
				return -EINVAL;
		}
	}
	return 0;
}

/* Strategy function to convert jiffies to seconds */ 
2730
int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
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		void __user *oldval, size_t __user *oldlenp,
2732
		void __user *newval, size_t newlen)
L
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{
2734
	if (oldval && oldlenp) {
L
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		size_t olen;
2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748

		if (get_user(olen, oldlenp))
			return -EFAULT;
		if (olen) {
			int val;

			if (olen < sizeof(int))
				return -EINVAL;

			val = *(int *)(table->data) / HZ;
			if (put_user(val, (int __user *)oldval))
				return -EFAULT;
			if (put_user(sizeof(int), oldlenp))
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				return -EFAULT;
		}
	}
	if (newval && newlen) { 
		int new;
		if (newlen != sizeof(int))
			return -EINVAL; 
		if (get_user(new, (int __user *)newval))
			return -EFAULT;
		*(int *)(table->data) = new*HZ; 
	}
	return 1;
}

/* Strategy function to convert jiffies to seconds */ 
2764
int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
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		void __user *oldval, size_t __user *oldlenp,
2766
		void __user *newval, size_t newlen)
L
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{
2768
	if (oldval && oldlenp) {
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		size_t olen;
2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782

		if (get_user(olen, oldlenp))
			return -EFAULT;
		if (olen) {
			int val;

			if (olen < sizeof(int))
				return -EINVAL;

			val = jiffies_to_msecs(*(int *)(table->data));
			if (put_user(val, (int __user *)oldval))
				return -EFAULT;
			if (put_user(sizeof(int), oldlenp))
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				return -EFAULT;
		}
	}
	if (newval && newlen) { 
		int new;
		if (newlen != sizeof(int))
			return -EINVAL; 
		if (get_user(new, (int __user *)newval))
			return -EFAULT;
		*(int *)(table->data) = msecs_to_jiffies(new);
	}
	return 1;
}

2797 2798


2799
#else /* CONFIG_SYSCTL_SYSCALL */
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asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
{
2804
	struct __sysctl_args tmp;
2805
	int error;
2806 2807 2808 2809

	if (copy_from_user(&tmp, args, sizeof(tmp)))
		return -EFAULT;

2810
	error = deprecated_sysctl_warning(&tmp);
2811

2812 2813 2814 2815 2816
	/* If no error reading the parameters then just -ENOSYS ... */
	if (!error)
		error = -ENOSYS;

	return error;
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}

2819 2820 2821 2822 2823 2824 2825
int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
		  void __user *oldval, size_t __user *oldlenp,
		  void __user *newval, size_t newlen)
{
	return -ENOSYS;
}

2826
int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
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		  void __user *oldval, size_t __user *oldlenp,
2828
		  void __user *newval, size_t newlen)
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{
	return -ENOSYS;
}

2833
int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
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		void __user *oldval, size_t __user *oldlenp,
2835
		void __user *newval, size_t newlen)
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{
	return -ENOSYS;
}

2840
int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
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		void __user *oldval, size_t __user *oldlenp,
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		void __user *newval, size_t newlen)
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{
	return -ENOSYS;
}

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int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
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		void __user *oldval, size_t __user *oldlenp,
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		void __user *newval, size_t newlen)
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{
	return -ENOSYS;
}

2854
#endif /* CONFIG_SYSCTL_SYSCALL */
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static int deprecated_sysctl_warning(struct __sysctl_args *args)
{
	static int msg_count;
	int name[CTL_MAXNAME];
	int i;

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	/* Check args->nlen. */
	if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
		return -ENOTDIR;

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	/* Read in the sysctl name for better debug message logging */
	for (i = 0; i < args->nlen; i++)
		if (get_user(name[i], args->name + i))
			return -EFAULT;

	/* Ignore accesses to kernel.version */
	if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
		return 0;

	if (msg_count < 5) {
		msg_count++;
		printk(KERN_INFO
			"warning: process `%s' used the deprecated sysctl "
			"system call with ", current->comm);
		for (i = 0; i < args->nlen; i++)
			printk("%d.", name[i]);
		printk("\n");
	}
	return 0;
}

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/*
 * No sense putting this after each symbol definition, twice,
 * exception granted :-)
 */
EXPORT_SYMBOL(proc_dointvec);
EXPORT_SYMBOL(proc_dointvec_jiffies);
EXPORT_SYMBOL(proc_dointvec_minmax);
EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
EXPORT_SYMBOL(proc_dostring);
EXPORT_SYMBOL(proc_doulongvec_minmax);
EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
EXPORT_SYMBOL(register_sysctl_table);
2900
EXPORT_SYMBOL(register_sysctl_paths);
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EXPORT_SYMBOL(sysctl_intvec);
EXPORT_SYMBOL(sysctl_jiffies);
EXPORT_SYMBOL(sysctl_ms_jiffies);
EXPORT_SYMBOL(sysctl_string);
2905
EXPORT_SYMBOL(sysctl_data);
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EXPORT_SYMBOL(unregister_sysctl_table);