Split usermem package to help remove syserror dependency in go_marshal.
New hostarch package contains code not dependent on syserror.
PiperOrigin-RevId: 365651233
Implement basic lazy save and restore for FPSIMD registers, which only
restore FPSIMD state on el0_fpsimd_acc and save FPSIMD state in switch().
Signed-off-by: Robin Luk <lubin.lu@antgroup.com>
In order to improve the performance and stability, I reorg 2 modules slightly.
arch: no red zone on Arm64.
ring0: use stp instead of movd, and set RSV_REG_APP=R19.
Signed-off-by: Robin Luk <lubin.lu@antgroup.com>
This allows the package to serve as a general purpose ring0 support package, as
opposed to being bound to specific sentry platforms.
Updates #5039
PiperOrigin-RevId: 355220044
Zach Koopmans
Robin Luk
Adin Scannell