函数逻辑报告

函数名称：Some copy_from_user() implementations do not return the exact number of* bytes remaining to copy on a fault. But copy_mount_options() requires that.* Note that this function differs from copy_from_user() in that it will oops

函数原型：static long exact_copy_from_user(void *to, const void __user *from, unsigned long n)

返回类型：long

参数：