-#ifdef CONFIG_SYSCTL_SYSCALL
-/* Perform the actual read/write of a sysctl table entry. */
-static int do_sysctl_strategy(struct ctl_table_root *root,
- struct ctl_table *table,
- void __user *oldval, size_t __user *oldlenp,
- void __user *newval, size_t newlen)
-{
- int op = 0, rc;
-
- if (oldval)
- op |= MAY_READ;
- if (newval)
- op |= MAY_WRITE;
- if (sysctl_perm(root, table, op))
- return -EPERM;
-
- if (table->strategy) {
- rc = table->strategy(table, 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, 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,
- struct ctl_table_root *root,
- 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(root, table, MAY_EXEC))
- return -EPERM;
- name++;
- nlen--;
- table = table->child;
- goto repeat;
- }
- error = do_sysctl_strategy(root, table,
- oldval, oldlenp,
- newval, newlen);
- return error;
- }
- }
- return -ENOTDIR;
-}
-
-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->root, head->ctl_table);
- if (error != -ENOTDIR) {
- sysctl_head_finish(head);
- break;
- }
- }
- return error;
-}
-
-SYSCALL_DEFINE1(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 */
-