On Mon, May 25, 2020 at 9:35 PM Lai Jiangshan <la...@linux.alibaba.com> wrote:
>
> 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.This series looks correct, but I don't think it's 5.8 material. I also want to try moving all this code to C, so it's possible this little series will become obsolete. > > 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 >
