interesting but not exactly brief.. :-)

On Fri, 31 May 2002, Jake Burkholder wrote:

> The system call stubs in libc are leaf functions; basically just a
> trap instruction followed by a return.  They do not touch the stack
> at all, or change the stack pointer.  One of the first few instructions
> on entry to the kernel is a save, which rotates the register window
> and logically saves the call-safe registers onto the user stack
> (the outs become the ins, and the kernel gets new ins and locals,
> with the old ones being saved to the user stack once a flush is
> performed or they get spilled out).

the question is "when does it switch to the kernel stack?"
(and back?)

> Here is a reference:

downloaded... 300+ pages.. hmm.

> Jake

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