Messages in this thread | | | Date | Wed, 17 Jan 2018 08:45:03 -0600 | From | Josh Poimboeuf <> | Subject | Re: [PATCH 03/16] x86/entry/32: Leave the kernel via the trampoline stack |
| |
On Wed, Jan 17, 2018 at 03:14:18PM +0100, Joerg Roedel wrote: > 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@gmail.com> 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.
If you put it at the end of the stack page, I _think_ all you'd have to do is just adjust TOP_OF_KERNEL_STACK_PADDING.
-- Josh
| |