operating system - Why does syscall need to switch into kernel mode? -


I am studying the final for my operating system and wondering if someone can tell me that the OS has to be kernel mode Why is there a need to change in Syscalls

To run the operating, a syscall is used specifically for security reasons. For example, if you want to allocate memory, then the operating system is privileged to do it (because it knows the pages tables and access to the memory of others is permitted), but as a user program The memory of other processes should not be allowed to peek or waste. If you have a way of sandboxing, you send a sscroll to allocate memory to the operating system, and it happens at the kernel level.

EDIT: Now I think it is surprisingly useful on this


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