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 ?
>
> nattu.
1) The user stack could be invalid. An invalid stack in the kernel will
cause the processor to double fault (see the recent double fault thread).
2) Security. You could set up the stack pointer from userspace so that
the kernel would overwrite memory that userspace can't access.
3) Security #2. You don't want to give userspace access to certain data
written to the stack in kernel mode.
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This archive was generated by hypermail 2b29 : Sun Feb 23 2003 - 22:00:34 EST