Re: [PATCH 03/16] x86/entry/32: Leave the kernel via the trampoline stack

[Joerg Roedel]

On Wed, Jan 17, 2018 at 06:00:07AM -0800, Brian Gerst wrote:
> On Wed, Jan 17, 2018 at 5:57 AM, Brian Gerst <brgerst@xxxxxxxxx> wrote:
> But then again, you could take a fault on the trampoline stack if you
> get a bad segment.  Perhaps just pushing the new stack pointer onto
> the process stack before user segment loads will be the right move.

User segment loads pop from the stack, so having anything on-top also
doesn't work.

Maybe I can leave some space at the bottom of the task-stack at entry
time and store the pointer there on exit, if that doesn't confuse the
stack unwinder too much.


	Joerg