artful pti branch review

[Daniel Drake]

Hi,

Thanks for sharing the 4.13 work-in-progress on the pti branch.

I have compared the list of commits
(https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/artful/log/?h=pti
at Ubuntu-4.13.0-24.28) to the commits that I made while taking my own
attempt at this task.

Based on the commits that I chose and you didn't, I think you might
want to consider also adding these patches from the v4.14.x stable
series:

commit c91f3fc2411d9f007fbbaf9b10f772805e01cafe
Author: Andy Lutomirski <luto at kernel.org>
Date:   Tue Nov 21 20:43:56 2017 -0800

    x86/entry/64: Fix entry_SYSCALL_64_after_hwframe() IRQ tracing

commit 211ad3fdf63383772d492add846da4b0b2266531
Author: Thomas Gleixner <tglx at linutronix.de>
Date:   Wed Jan 3 15:57:59 2018 +0100

    x86/pti: Make sure the user/kernel PTEs match


And since you are turning on PCID I think you should consider these
fixes made during the 4.14 development cycle:

commit 924c6b900cfdf376b07bccfd80e62b21914f8a5a
Author: Andy Lutomirski <luto at kernel.org>
Date:   Sun Oct 8 21:53:05 2017 -0700

    x86/mm/64: Fix reboot interaction with CR4.PCIDE

commit cba4671af7550e008f7a7835f06df0763825bf3e
Author: Andy Lutomirski <luto at kernel.org>
Date:   Thu Jun 29 08:53:19 2017 -0700

    x86/mm: Disable PCID on 32-bit kernels

commit 72c0098d92cedb11c7e0151e84918840a4e96b31
Author: Andy Lutomirski <luto at kernel.org>
Date:   Wed Sep 6 19:54:53 2017 -0700

    x86/mm: Reinitialize TLB state on hotplug and resume

commit 4ba55e65f471d011d3ba2ac2022180ea0877d68e
Author: Andy Lutomirski <luto at kernel.org>
Date:   Sun Sep 17 09:03:51 2017 -0700

    x86/mm/32: Load a sane CR3 before cpu_init() on secondary CPUs


Please let me know if there's any other way to help push forward this
branch so that it is released promptly.

Daniel