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SubjectRe: A question on kernel stack
nataraja kumar wrote:
>
> hi,
> my apologies if i am wrong. please let me know
> why does kernel use kernel stack when process jumps
> from user mode to kernel mode. why can't user stack
> be used ?

1) The user stack is in user space, which can only be
accessed by this process (or any sharing the same
vm). Trying to access the stack of another process
would fail.
2) The stack pointer is used to find the task_struct
of the current process. You'd need another location
for the task_struct, and a way to find it.
3) Various security issues as others have already
mentioned.

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