Re: [patch] x86/realmode: Make stack lock work in trampoline_compat()

From: Yunhong Jiang
Date: Thu Jun 08 2023 - 19:36:20 EST


On Tue, May 30, 2023 at 12:46:22PM +0200, Thomas Gleixner wrote:
> The stack locking and stack assignment macro LOAD_REALMODE_ESP fails to
> work when invoked from the 64bit trampoline entry point:
>
> trampoline_start64
> trampoline_compat
> LOAD_REALMODE_ESP <- lock
One possibly dumb question and hope get some hints. The LOAD_REALMODE_ESP is
defined under .code16 directive and will be used by 32-bit mode caller also. Is
it ok because the instructions there will be same for both 16-bit and 32-bit? I
checked
https://ftp.gnu.org/old-gnu/Manuals/gas-2.9.1/html_chapter/as_16.html#SEC205 and
don't find much information there.