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// SPDX-License-Identifier: GPL-2.0-only
/*
* sysctl.c: General linux system control interface
*/
#include <linux/sysctl.h>
#include <linux/printk.h>
#include <linux/capability.h>
#include <linux/ratelimit.h>
#include "internal.h"
static const int ten_thousand = 10000;
static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
if (write && !capable(CAP_SYS_ADMIN))
return -EPERM;
return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
}
static struct ctl_table printk_sysctls[] = {
{
.procname = "printk",
.data = &console_loglevel,
.maxlen = 4*sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "printk_ratelimit",
.data = &printk_ratelimit_state.interval,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "printk_ratelimit_burst",
.data = &printk_ratelimit_state.burst,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "printk_delay",
.data = &printk_delay_msec,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = (void *)&ten_thousand,
},
{
.procname = "printk_devkmsg",
.data = devkmsg_log_str,
.maxlen = DEVKMSG_STR_MAX_SIZE,
.mode = 0644,
.proc_handler = devkmsg_sysctl_set_loglvl,
},
{
.procname = "dmesg_restrict",
.data = &dmesg_restrict,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax_sysadmin,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
{
.procname = "kptr_restrict",
.data = &kptr_restrict,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax_sysadmin,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_TWO,
},
{}
};
void __init printk_sysctl_init(void)
{
register_sysctl_init("kernel", printk_sysctls);
}
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