Re: A question on kernel stack

From: Kasper Dupont (kasperd@daimi.au.dk)
Date: Sun Feb 23 2003 - 09:33:21 EST

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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.

-- 
Kasper Dupont -- der bruger for meget tid på usenet.
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Next message: Abraham van der Merwe: "BUG REPORT: bug in eepro100.c driver"
Previous message: Stephan von Krawczynski: "Re: 2.4.21-pre4: PDC ide driver problems with shared interrupts"
In reply to: nataraja kumar: "A question on kernel stack"
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