Suppose you're building a map application. You have millions of restaurants, gas stations, and landmarks, each with a latitude and longitude. A user taps the screen and asks: "What's near me?"
Understanding the trigger model #。业内人士推荐新收录的资料作为进阶阅读
— Pull current branch: A dedicated command for git pull origin <current-branch。PDF资料对此有专业解读
What is striking about this implementation is that it does not involve CR0.WP. The implementation elegantly sidesteps this by exploiting the fact that it is under no obligation to access memory via the pointer it receives from userspace. Since the kernel is in complete control of virtual memory, it can simply remap the physical frame into its own virtual address space, with arbitrary permissions, and operate on it as it wishes.