When I searched percpu data touched by entry code for #DB
protection[1], it seems to me RESTORE_CR3() does too much work,
this patchset simplifies it.
Patch 1 enhances 21e944591102("x86/mm: Optimize RESTORE_CR3") for
kernel CR3.
Patch 2 *reverts* 21e944591102("x86/mm: Optimize RESTORE_CR3") for
User CR3.
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: x...@kernel.org
Link:
https://lore.kernel.org/lkml/20200525145102.122557-1-la...@linux.alibaba.com
Lai Jiangshan (2):
x86/entry: Don't write to CR3 when restoring to kernel CR3
x86/entry: always flush user CR3 in RESTORE_CR3
arch/x86/entry/calling.h | 36 ++++++++----------------------------
arch/x86/entry/entry_64.S | 6 +++---
2 files changed, 11 insertions(+), 31 deletions(-)
--
2.20.1
