strnlen_user
extern __must_check long strnlen_user(const char __user *str, long n);
extern __must_check long strnlen_user(const char __user *str, long n);
extern __must_check long strnlen_user(const char __user *str, long n);
extern long strnlen_user(const char __user *str, long n);
extern __must_check long strnlen_user(const char __user *str, long n);
__must_check long strnlen_user(const char __user *sstr, long len);
extern __must_check long strnlen_user(const char __user *s, long n);
extern __must_check long strnlen_user(const char __user *str, long n);
extern __must_check long strnlen_user(const char __user *src, long n);
extern __must_check long strnlen_user(const char __user *str, long n);
extern long __must_check strnlen_user(const char __user *str, long n);
long __must_check strnlen_user(const char __user *src, long count);
extern __must_check long strnlen_user(const char __user *str, long n);
__must_check long strnlen_user(const char __user *str, long n);
__must_check long strnlen_user(const char __user *str, long n);
EXPORT_SYMBOL(strnlen_user);
extern __must_check long strnlen_user(const char __user *str, long n);
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
len = strnlen_user(p, MAX_ARG_STRLEN);
len = strnlen_user(p, MAX_ARG_STRLEN);
len = strnlen_user(p, MAX_ARG_STRLEN);
len = strnlen_user(p, MAX_ARG_STRLEN);
len = strnlen_user(str, MAX_ARG_STRLEN);
__must_check long strnlen_user(const char __user *src, long n);
len_full = strnlen_user(p, MAX_ARG_STRLEN) - 1;
len = strnlen_user(vaddr, MAX_STRING_SIZE);
EXPORT_SYMBOL(strnlen_user);
ret = strnlen_user(unsafe_addr, count);
length = strnlen_user(s, n);