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linux/kernel/sysctl.c

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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>
#include <linux/security.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/net.h>
#include <linux/sysrq.h>
#include <linux/highuid.h>
#include <linux/writeback.h>
#include <linux/hugetlb.h>
#include <linux/initrd.h>
#include <linux/times.h>
#include <linux/limits.h>
#include <linux/dcache.h>
#include <linux/syscalls.h>
#include <linux/nfs_fs.h>
#include <linux/acpi.h>
#include <linux/reboot.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#ifdef CONFIG_X86
#include <asm/nmi.h>
#include <asm/stacktrace.h>
#include <asm/io.h>
#endif
static int deprecated_sysctl_warning(struct __sysctl_args *args);
#if defined(CONFIG_SYSCTL)
/* External variables not in a header file. */
extern int C_A_D;
extern int print_fatal_signals;
extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern int sysctl_panic_on_oom;
extern int sysctl_oom_kill_allocating_task;
extern int sysctl_oom_dump_tasks;
extern int max_threads;
extern int core_uses_pid;
extern int suid_dumpable;
extern char core_pattern[];
extern int pid_max;
extern int min_free_kbytes;
extern int pid_max_min, pid_max_max;
extern int sysctl_drop_caches;
extern int percpu_pagelist_fraction;
extern int compat_log;
extern int maps_protect;
extern int sysctl_stat_interval;
extern int latencytop_enabled;
/* Constants used for minimum and maximum */
#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM)
static int one = 1;
#endif
#ifdef CONFIG_DETECT_SOFTLOCKUP
static int sixty = 60;
#endif
#ifdef CONFIG_MMU
static int two = 2;
#endif
static int zero;
static int one_hundred = 100;
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
static int minolduid;
static int min_percpu_pagelist_fract = 8;
static int ngroups_max = NGROUPS_MAX;
#ifdef CONFIG_KMOD
extern char modprobe_path[];
#endif
#ifdef CONFIG_CHR_DEV_SG
extern int sg_big_buff;
#endif
#ifdef __sparc__
extern char reboot_command [];
extern int stop_a_enabled;
extern int scons_pwroff;
#endif
#ifdef __hppa__
extern int pwrsw_enabled;
extern int unaligned_enabled;
#endif
#ifdef CONFIG_S390
#ifdef CONFIG_MATHEMU
extern int sysctl_ieee_emulation_warnings;
#endif
extern int sysctl_userprocess_debug;
extern int spin_retry;
#endif
extern int sysctl_hz_timer;
#ifdef CONFIG_BSD_PROCESS_ACCT
extern int acct_parm[];
#endif
#ifdef CONFIG_IA64
extern int no_unaligned_warning;
#endif
#ifdef CONFIG_RT_MUTEXES
extern int max_lock_depth;
#endif
#ifdef CONFIG_SYSCTL_SYSCALL
static int parse_table(int __user *, int, void __user *, size_t __user *,
void __user *, size_t, struct ctl_table *);
#endif
#ifdef CONFIG_PROC_SYSCTL
static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
#endif
static struct ctl_table root_table[];
static struct ctl_table_root sysctl_table_root;
static struct ctl_table_header root_table_header = {
.ctl_table = root_table,
.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.header_list),
.root = &sysctl_table_root,
};
static struct ctl_table_root sysctl_table_root = {
.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
.header_list = LIST_HEAD_INIT(root_table_header.ctl_entry),
};
static struct ctl_table kern_table[];
static struct ctl_table vm_table[];
static struct ctl_table fs_table[];
static struct ctl_table debug_table[];
static struct ctl_table dev_table[];
extern struct ctl_table random_table[];
#ifdef CONFIG_INOTIFY_USER
extern struct ctl_table inotify_table[];
#endif
#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
int sysctl_legacy_va_layout;
#endif
extern int prove_locking;
extern int lock_stat;
/* The default sysctl tables: */
static struct ctl_table root_table[] = {
{
.ctl_name = CTL_KERN,
.procname = "kernel",
.mode = 0555,
.child = kern_table,
},
{
.ctl_name = CTL_VM,
.procname = "vm",
.mode = 0555,
.child = vm_table,
},
{
.ctl_name = CTL_FS,
.procname = "fs",
.mode = 0555,
.child = fs_table,
},
{
.ctl_name = CTL_DEBUG,
.procname = "debug",
.mode = 0555,
.child = debug_table,
},
{
.ctl_name = CTL_DEV,
.procname = "dev",
.mode = 0555,
.child = dev_table,
},
/*
* NOTE: do not add new entries to this table unless you have read
* Documentation/sysctl/ctl_unnumbered.txt
*/
{ .ctl_name = 0 }
};
#ifdef CONFIG_SCHED_DEBUG
static int min_sched_granularity_ns = 100000; /* 100 usecs */
static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
static int min_wakeup_granularity_ns; /* 0 usecs */
static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
#endif
static struct ctl_table kern_table[] = {
#ifdef CONFIG_SCHED_DEBUG
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_min_granularity_ns",
.data = &sysctl_sched_min_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &sched_nr_latency_handler,
.strategy = &sysctl_intvec,
.extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_latency_ns",
.data = &sysctl_sched_latency,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &sched_nr_latency_handler,
.strategy = &sysctl_intvec,
.extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_wakeup_granularity_ns",
.data = &sysctl_sched_wakeup_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &min_wakeup_granularity_ns,
.extra2 = &max_wakeup_granularity_ns,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_batch_wakeup_granularity_ns",
.data = &sysctl_sched_batch_wakeup_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &min_wakeup_granularity_ns,
.extra2 = &max_wakeup_granularity_ns,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_child_runs_first",
.data = &sysctl_sched_child_runs_first,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_features",
.data = &sysctl_sched_features,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_migration_cost",
.data = &sysctl_sched_migration_cost,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_nr_migrate",
.data = &sysctl_sched_nr_migrate,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_SMP)
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_min_bal_int_shares",
.data = &sysctl_sched_min_bal_int_shares,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_max_bal_int_shares",
.data = &sysctl_sched_max_bal_int_shares,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#endif
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_rt_period_us",
.data = &sysctl_sched_rt_period,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_rt_runtime_us",
.data = &sysctl_sched_rt_runtime,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_compat_yield",
.data = &sysctl_sched_compat_yield,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#ifdef CONFIG_PROVE_LOCKING
{
.ctl_name = CTL_UNNUMBERED,
.procname = "prove_locking",
.data = &prove_locking,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#ifdef CONFIG_LOCK_STAT
{
.ctl_name = CTL_UNNUMBERED,
.procname = "lock_stat",
.data = &lock_stat,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
{
.ctl_name = KERN_PANIC,
.procname = "panic",
.data = &panic_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = KERN_CORE_USES_PID,
.procname = "core_uses_pid",
.data = &core_uses_pid,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = KERN_CORE_PATTERN,
.procname = "core_pattern",
.data = core_pattern,
.maxlen = CORENAME_MAX_SIZE,
.mode = 0644,
.proc_handler = &proc_dostring,
.strategy = &sysctl_string,
},
#ifdef CONFIG_PROC_SYSCTL
{
.procname = "tainted",
.data = &tainted,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_taint,
},
#endif
#ifdef CONFIG_LATENCYTOP
{
.procname = "latencytop",
.data = &latencytop_enabled,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#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
{
.ctl_name = CTL_UNNUMBERED,
.procname = "print-fatal-signals",
.data = &print_fatal_signals,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#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,
},
#ifdef CONFIG_KMOD
{
.ctl_name = KERN_MODPROBE,
.procname = "modprobe",
.data = &modprobe_path,
.maxlen = KMOD_PATH_LEN,
.mode = 0644,
.proc_handler = &proc_dostring,
.strategy = &sysctl_string,
},
#endif
#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
{
.ctl_name = KERN_HOTPLUG,
.procname = "hotplug",
.data = &uevent_helper,
.maxlen = UEVENT_HELPER_PATH_LEN,
.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",
.data = &__sysrq_enabled,
.maxlen = sizeof (int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#ifdef CONFIG_PROC_SYSCTL
{
.procname = "cad_pid",
.data = NULL,
.maxlen = sizeof (int),
.mode = 0600,
.proc_handler = &proc_do_cad_pid,
},
#endif
{
.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,
},
#ifdef CONFIG_S390
#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
#ifdef CONFIG_NO_IDLE_HZ
{
.ctl_name = KERN_HZ_TIMER,
.procname = "hz_timer",
.data = &sysctl_hz_timer,
.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,
},
#if defined CONFIG_PRINTK
{
.ctl_name = KERN_PRINTK,
.procname = "printk",
.data = &console_loglevel,
.maxlen = 4*sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = KERN_PRINTK_RATELIMIT,
.procname = "printk_ratelimit",
.data = &printk_ratelimit_jiffies,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_jiffies,
.strategy = &sysctl_jiffies,
},
{
.ctl_name = KERN_PRINTK_RATELIMIT_BURST,
.procname = "printk_ratelimit_burst",
.data = &printk_ratelimit_burst,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
{
.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,
.proc_handler = &proc_dointvec,
},
{
.procname = "nmi_watchdog",
.data = &nmi_watchdog_enabled,
.maxlen = sizeof (int),
.mode = 0644,
.proc_handler = &proc_nmi_enabled,
},
#endif
#if defined(CONFIG_X86)
{
.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,
},
{
.ctl_name = KERN_BOOTLOADER_TYPE,
.procname = "bootloader_type",
.data = &bootloader_type,
.maxlen = sizeof (int),
.mode = 0444,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "kstack_depth_to_print",
.data = &kstack_depth_to_print,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "io_delay_type",
.data = &io_delay_type,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#if defined(CONFIG_MMU)
{
.ctl_name = KERN_RANDOMIZE,
.procname = "randomize_va_space",
.data = &randomize_va_space,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#if defined(CONFIG_S390) && defined(CONFIG_SMP)
{
.ctl_name = KERN_SPIN_RETRY,
.procname = "spin_retry",
.data = &spin_retry,
.maxlen = sizeof (int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
{
.procname = "acpi_video_flags",
.data = &acpi_realmode_flags,
.maxlen = sizeof (unsigned long),
.mode = 0644,
.proc_handler = &proc_doulongvec_minmax,
},
#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,
},
#endif
#ifdef CONFIG_DETECT_SOFTLOCKUP
{
.ctl_name = CTL_UNNUMBERED,
.procname = "softlockup_thresh",
.data = &softlockup_thresh,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = &proc_doulongvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &one,
.extra2 = &sixty,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "hung_task_check_count",
.data = &sysctl_hung_task_check_count,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = &proc_doulongvec_minmax,
.strategy = &sysctl_intvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "hung_task_timeout_secs",
.data = &sysctl_hung_task_timeout_secs,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = &proc_doulongvec_minmax,
.strategy = &sysctl_intvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "hung_task_warnings",
.data = &sysctl_hung_task_warnings,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = &proc_doulongvec_minmax,
.strategy = &sysctl_intvec,
},
#endif
#ifdef CONFIG_COMPAT
{
.ctl_name = KERN_COMPAT_LOG,
.procname = "compat-log",
.data = &compat_log,
.maxlen = sizeof (int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
#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
#ifdef CONFIG_PROC_FS
{
.ctl_name = CTL_UNNUMBERED,
.procname = "maps_protect",
.data = &maps_protect,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
{
.ctl_name = CTL_UNNUMBERED,
.procname = "poweroff_cmd",
.data = &poweroff_cmd,
.maxlen = POWEROFF_CMD_PATH_LEN,
.mode = 0644,
.proc_handler = &proc_dostring,
.strategy = &sysctl_string,
},
/*
* NOTE: do not add new entries to this table unless you have read
* Documentation/sysctl/ctl_unnumbered.txt
*/
{ .ctl_name = 0 }
};
static struct ctl_table vm_table[] = {
{
.ctl_name = VM_OVERCOMMIT_MEMORY,
.procname = "overcommit_memory",
.data = &sysctl_overcommit_memory,
.maxlen = sizeof(sysctl_overcommit_memory),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.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,
},
{
.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,
},
{
.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,
},
{
.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,
.proc_handler = &dirty_ratio_handler,
.strategy = &sysctl_intvec,
.extra1 = &zero,
.extra2 = &one_hundred,
},
{
.procname = "dirty_writeback_centisecs",
.data = &dirty_writeback_interval,
.maxlen = sizeof(dirty_writeback_interval),
.mode = 0644,
.proc_handler = &dirty_writeback_centisecs_handler,
},
{
.procname = "dirty_expire_centisecs",
.data = &dirty_expire_interval,
.maxlen = sizeof(dirty_expire_interval),
.mode = 0644,
.proc_handler = &proc_dointvec_userhz_jiffies,
},
{
.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",
.data = &max_huge_pages,
.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,
},
{
.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,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "nr_overcommit_hugepages",
.data = &sysctl_overcommit_huge_pages,
.maxlen = sizeof(sysctl_overcommit_huge_pages),
.mode = 0644,
.proc_handler = &hugetlb_overcommit_handler,
},
#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,
},
{
.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,
},
{
.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,
},
{
.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,
},
#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,
.proc_handler = &proc_dointvec_jiffies,
.strategy = &sysctl_jiffies,
},
{
.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
#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,
.strategy = &sysctl_intvec,
.extra1 = &zero,
},
{
.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,
},
{
.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,
},
#endif
#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
#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,
},
#endif
#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
#if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
(defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
{
.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,
},
#endif
#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
/*
* NOTE: do not add new entries to this table unless you have read
* Documentation/sysctl/ctl_unnumbered.txt
*/
{ .ctl_name = 0 }
};
#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
static struct ctl_table binfmt_misc_table[] = {
{ .ctl_name = 0 }
};
#endif
static struct ctl_table fs_table[] = {
{
.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,
.proc_handler = &proc_nr_files,
},
{
.ctl_name = FS_MAXFILE,
.procname = "file-max",
.data = &files_stat.max_files,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "nr_open",
.data = &sysctl_nr_open,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.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,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &zero,
.extra2 = &two,
},
{
.procname = "aio-nr",
.data = &aio_nr,
.maxlen = sizeof(aio_nr),
.mode = 0444,
.proc_handler = &proc_doulongvec_minmax,
},
{
.procname = "aio-max-nr",
.data = &aio_max_nr,
.maxlen = sizeof(aio_max_nr),
.mode = 0644,
.proc_handler = &proc_doulongvec_minmax,
},
#ifdef CONFIG_INOTIFY_USER
{
.ctl_name = FS_INOTIFY,
.procname = "inotify",
.mode = 0555,
.child = inotify_table,
},
#endif
#endif
{
.ctl_name = KERN_SETUID_DUMPABLE,
.procname = "suid_dumpable",
.data = &suid_dumpable,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
{
.ctl_name = CTL_UNNUMBERED,
.procname = "binfmt_misc",
.mode = 0555,
.child = binfmt_misc_table,
},
#endif
/*
* NOTE: do not add new entries to this table unless you have read
* Documentation/sysctl/ctl_unnumbered.txt
*/
{ .ctl_name = 0 }
};
static struct ctl_table debug_table[] = {
#if defined(CONFIG_X86) || defined(CONFIG_PPC)
{
.ctl_name = CTL_UNNUMBERED,
.procname = "exception-trace",
.data = &show_unhandled_signals,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
#endif
{ .ctl_name = 0 }
};
static struct ctl_table dev_table[] = {
{ .ctl_name = 0 }
};
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);
}
void sysctl_head_finish(struct ctl_table_header *head)
{
if (!head)
return;
spin_lock(&sysctl_lock);
unuse_table(head);
spin_unlock(&sysctl_lock);
}
static struct list_head *
lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
{
struct list_head *header_list;
header_list = &root->header_list;
if (root->lookup)
header_list = root->lookup(root, namespaces);
return header_list;
}
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;
struct ctl_table_header *head;
struct list_head *tmp;
spin_lock(&sysctl_lock);
if (prev) {
head = prev;
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:
root = head->root;
tmp = tmp->next;
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;
}
out:
spin_unlock(&sysctl_lock);
return NULL;
}
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);
}
#ifdef CONFIG_SYSCTL_SYSCALL
int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
struct ctl_table_header *head;
int error = -ENOTDIR;
if (nlen <= 0 || nlen >= CTL_MAXNAME)
return -ENOTDIR;
if (oldval) {
int old_len;
if (!oldlenp || get_user(old_len, oldlenp))
return -EFAULT;
}
for (head = sysctl_head_next(NULL); head;
head = sysctl_head_next(head)) {
error = parse_table(name, nlen, oldval, oldlenp,
newval, newlen, head->ctl_table);
if (error != -ENOTDIR) {
sysctl_head_finish(head);
break;
}
}
return error;
}
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;
error = deprecated_sysctl_warning(&tmp);
if (error)
goto out;
lock_kernel();
error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
tmp.newval, tmp.newlen);
unlock_kernel();
out:
return error;
}
#endif /* CONFIG_SYSCTL_SYSCALL */
/*
* sysctl_perm does NOT grant the superuser all rights automatically, because
* 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;
}
int sysctl_perm(struct ctl_table *table, int op)
{
int error;
error = security_sysctl(table, op);
if (error)
return error;
return test_perm(table->mode, op);
}
#ifdef CONFIG_SYSCTL_SYSCALL
static int parse_table(int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen,
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) {
if (sysctl_perm(table, 001))
return -EPERM;
name++;
nlen--;
table = table->child;
goto repeat;
}
error = do_sysctl_strategy(table, name, nlen,
oldval, oldlenp,
newval, newlen);
return error;
}
}
return -ENOTDIR;
}
/* Perform the actual read/write of a sysctl table entry. */
int do_sysctl_strategy (struct ctl_table *table,
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;
if (sysctl_perm(table, op))
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;
}
#endif /* CONFIG_SYSCTL_SYSCALL */
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)
{
int err;
sysctl_set_parent(NULL, root_table);
err = sysctl_check_table(current->nsproxy, root_table);
return 0;
}
core_initcall(sysctl_init);
/**
* __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
* @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.
*
* The members of the &struct ctl_table structure are used as follows:
*
* 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.
*/
struct ctl_table_header *__register_sysctl_paths(
struct ctl_table_root *root,
struct nsproxy *namespaces,
const struct ctl_path *path, struct ctl_table *table)
{
struct list_head *header_list;
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)
return NULL;
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;
header->ctl_table_arg = table;
INIT_LIST_HEAD(&header->ctl_entry);
header->used = 0;
header->unregistering = NULL;
header->root = root;
sysctl_set_parent(NULL, header->ctl_table);
if (sysctl_check_table(namespaces, header->ctl_table)) {
kfree(header);
return NULL;
}
spin_lock(&sysctl_lock);
header_list = lookup_header_list(root, namespaces);
list_add_tail(&header->ctl_entry, header_list);
spin_unlock(&sysctl_lock);
return header;
}
/**
* 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);
}
/**
* 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);
}
/**
* 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)
{
might_sleep();
if (header == NULL)
return;
spin_lock(&sysctl_lock);
start_unregistering(header);
spin_unlock(&sysctl_lock);
kfree(header);
}
#else /* !CONFIG_SYSCTL */
struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
{
return NULL;
}
struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
struct ctl_table *table)
{
return NULL;
}
void unregister_sysctl_table(struct ctl_table_header * table)
{
}
#endif /* CONFIG_SYSCTL */
/*
* /proc/sys support
*/
#ifdef CONFIG_PROC_SYSCTL
static int _proc_do_string(void* data, int maxlen, int write,
struct file *filp, void __user *buffer,
size_t *lenp, loff_t *ppos)
{
size_t len;
char __user *p;
char c;
if (!data || !maxlen || !*lenp) {
*lenp = 0;
return 0;
}
if (write) {
len = 0;
p = buffer;
while (len < *lenp) {
if (get_user(c, p++))
return -EFAULT;
if (c == 0 || c == '\n')
break;
len++;
}
if (len >= maxlen)
len = maxlen-1;
if(copy_from_user(data, buffer, len))
return -EFAULT;
((char *) data)[len] = 0;
*ppos += *lenp;
} else {
len = strlen(data);
if (len > maxlen)
len = maxlen;
if (*ppos > len) {
*lenp = 0;
return 0;
}
data += *ppos;
len -= *ppos;
if (len > *lenp)
len = *lenp;
if (len)
if(copy_to_user(buffer, data, len))
return -EFAULT;
if (len < *lenp) {
if(put_user('\n', ((char __user *) buffer) + len))
return -EFAULT;
len++;
}
*lenp = len;
*ppos += len;
}
return 0;
}
/**
* 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.
*/
int proc_dostring(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return _proc_do_string(table->data, table->maxlen, write, filp,
buffer, lenp, ppos);
}
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;
}
static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
int write, struct file *filp, void __user *buffer,
size_t *lenp, loff_t *ppos,
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;
if (!tbl_data || !table->maxlen || !*lenp ||
(*ppos && !write)) {
*lenp = 0;
return 0;
}
i = (int *) tbl_data;
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;
p++;
}
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
}
static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
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);
}
/**
* 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.
*/
int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
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
#define OP_OR 2
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;
case OP_OR: *valp |= val; break;
}
} else {
int val = *valp;
if (val < 0) {
*negp = -1;
*lvalp = (unsigned long)-val;
} else {
*negp = 0;
*lvalp = (unsigned long)val;
}
}
return 0;
}
/*
* Taint values can only be increased
*/
static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
int op;
if (write && !capable(CAP_SYS_ADMIN))
return -EPERM;
op = OP_OR;
return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
do_proc_dointvec_bset_conv,&op);
}
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.
*/
int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
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);
}
static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
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;
if (!data || !table->maxlen || !*lenp ||
(*ppos && !write)) {
*lenp = 0;
return 0;
}
i = (unsigned long *) data;
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;
p++;
}
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
}
static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
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);
}
/**
* 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.
*/
int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
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.
*/
int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
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) {
if (*lvalp > LONG_MAX / HZ)
return 1;
*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) {
if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
return 1;
*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.
*/
int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
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
* @ppos: pointer to the 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 1/USER_HZ seconds, and
* are converted into jiffies.
*
* Returns 0 on success.
*/
int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
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
* @ppos: file position
* @ppos: the current position in the file
*
* 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.
*/
int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
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);
}
static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct pid *new_pid;
pid_t tmp;
int r;
tmp = pid_vnr(cad_pid);
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;
}
#else /* CONFIG_PROC_FS */
int proc_dostring(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
struct file *filp,
void __user *buffer,
size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
#endif /* CONFIG_PROC_FS */
#ifdef CONFIG_SYSCTL_SYSCALL
/*
* General sysctl support routines
*/
/* 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;
}
/* The generic string strategy routine: */
int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
if (!table->data || !table->maxlen)
return -ENOTDIR;
if (oldval && oldlenp) {
size_t bufsize;
if (get_user(bufsize, oldlenp))
return -EFAULT;
if (bufsize) {
size_t len = strlen(table->data), copied;
/* This shouldn't trigger for a well-formed sysctl */
if (len > table->maxlen)
len = table->maxlen;
/* 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)))
return -EFAULT;
if (put_user(len, oldlenp))
return -EFAULT;
}
}
if (newval && newlen) {
size_t len = newlen;
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;
}
return 1;
}
/*
* 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.
*/
int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
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 */
int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
if (oldval && oldlenp) {
size_t olen;
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))
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 */
int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
if (oldval && oldlenp) {
size_t olen;
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))
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;
}
#else /* CONFIG_SYSCTL_SYSCALL */
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;
error = deprecated_sysctl_warning(&tmp);
/* If no error reading the parameters then just -ENOSYS ... */
if (!error)
error = -ENOSYS;
return error;
}
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;
}
int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
return -ENOSYS;
}
int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
return -ENOSYS;
}
int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
return -ENOSYS;
}
int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
return -ENOSYS;
}
#endif /* CONFIG_SYSCTL_SYSCALL */
static int deprecated_sysctl_warning(struct __sysctl_args *args)
{
static int msg_count;
int name[CTL_MAXNAME];
int i;
/* Check args->nlen. */
if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
return -ENOTDIR;
/* 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;
}
/*
* 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);
EXPORT_SYMBOL(register_sysctl_paths);
EXPORT_SYMBOL(sysctl_intvec);
EXPORT_SYMBOL(sysctl_jiffies);
EXPORT_SYMBOL(sysctl_ms_jiffies);
EXPORT_SYMBOL(sysctl_string);
EXPORT_SYMBOL(sysctl_data);
EXPORT_SYMBOL(unregister_sysctl_table);
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