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// SPDX-License-Identifier: GPL-2.0
#include <linux/stat.h>
#include <linux/sysctl.h>
#include "../fs/xfs/xfs_sysctl.h"
#include <linux/sunrpc/debug.h>
#include <linux/string.h>
#include <linux/syscalls.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/fs.h>
#include <linux/nsproxy.h>
#include <linux/pid_namespace.h>
#include <linux/file.h>
#include <linux/ctype.h>
#include <linux/netdevice.h>
#include <linux/kernel.h>
#include <linux/uuid.h>
#include <linux/slab.h>
#include <linux/compat.h>
static ssize_t binary_sysctl(const int *name, int nlen,
void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
{
return -ENOSYS;
}
static void deprecated_sysctl_warning(const int *name, int nlen)
{
int i;
/*
* CTL_KERN/KERN_VERSION is used by older glibc and cannot
* ever go away.
*/
if (nlen >= 2 && name[0] == CTL_KERN && name[1] == KERN_VERSION)
return;
if (printk_ratelimit()) {
printk(KERN_INFO
"warning: process `%s' used the deprecated sysctl "
"system call with ", current->comm);
for (i = 0; i < nlen; i++)
printk(KERN_CONT "%d.", name[i]);
printk(KERN_CONT "\n");
}
return;
}
#define WARN_ONCE_HASH_BITS 8
#define WARN_ONCE_HASH_SIZE (1<<WARN_ONCE_HASH_BITS)
static DECLARE_BITMAP(warn_once_bitmap, WARN_ONCE_HASH_SIZE);
#define FNV32_OFFSET 2166136261U
#define FNV32_PRIME 0x01000193
/*
* Print each legacy sysctl (approximately) only once.
* To avoid making the tables non-const use a external
* hash-table instead.
* Worst case hash collision: 6, but very rarely.
* NOTE! We don't use the SMP-safe bit tests. We simply
* don't care enough.
*/
static void warn_on_bintable(const int *name, int nlen)
{
int i;
u32 hash = FNV32_OFFSET;
for (i = 0; i < nlen; i++)
hash = (hash ^ name[i]) * FNV32_PRIME;
hash %= WARN_ONCE_HASH_SIZE;
if (__test_and_set_bit(hash, warn_once_bitmap))
return;
deprecated_sysctl_warning(name, nlen);
}
static ssize_t do_sysctl(int __user *args_name, int nlen,
void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
{
int name[CTL_MAXNAME];
int i;
/* Check args->nlen. */
if (nlen < 0 || nlen > CTL_MAXNAME)
return -ENOTDIR;
/* Read in the sysctl name for simplicity */
for (i = 0; i < nlen; i++)
if (get_user(name[i], args_name + i))
return -EFAULT;
warn_on_bintable(name, nlen);
return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
}
SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
{
struct __sysctl_args tmp;
size_t oldlen = 0;
ssize_t result;
if (copy_from_user(&tmp, args, sizeof(tmp)))
return -EFAULT;
if (tmp.oldval && !tmp.oldlenp)
return -EFAULT;
if (tmp.oldlenp && get_user(oldlen, tmp.oldlenp))
return -EFAULT;
result = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, oldlen,
tmp.newval, tmp.newlen);
if (result >= 0) {
oldlen = result;
result = 0;
}
if (tmp.oldlenp && put_user(oldlen, tmp.oldlenp))
return -EFAULT;
return result;
}
#ifdef CONFIG_COMPAT
struct compat_sysctl_args {
compat_uptr_t name;
int nlen;
compat_uptr_t oldval;
compat_uptr_t oldlenp;
compat_uptr_t newval;
compat_size_t newlen;
compat_ulong_t __unused[4];
};
COMPAT_SYSCALL_DEFINE1(sysctl, struct compat_sysctl_args __user *, args)
{
struct compat_sysctl_args tmp;
compat_size_t __user *compat_oldlenp;
size_t oldlen = 0;
ssize_t result;
if (copy_from_user(&tmp, args, sizeof(tmp)))
return -EFAULT;
if (tmp.oldval && !tmp.oldlenp)
return -EFAULT;
compat_oldlenp = compat_ptr(tmp.oldlenp);
if (compat_oldlenp && get_user(oldlen, compat_oldlenp))
return -EFAULT;
result = do_sysctl(compat_ptr(tmp.name), tmp.nlen,
compat_ptr(tmp.oldval), oldlen,
compat_ptr(tmp.newval), tmp.newlen);
if (result >= 0) {
oldlen = result;
result = 0;
}
if (compat_oldlenp && put_user(oldlen, compat_oldlenp))
return -EFAULT;
return result;
}
#endif /* CONFIG_COMPAT */
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