Re: [PATCH v2 0/5] x86/fault: #PF improvements, mostly related to USER bit

[Peter Zijlstra <peterz@infradead.org>]

On Wed, Nov 21, 2018 at 03:11:21PM -0800, Andy Lutomirski wrote:
> This series is a whole bunch of page fault cleanups, plus a couple
> of OOPS diagnostic improvements.  The overall goals are to clean up
> handling of the faulting CPL, the USER bit in the error_code, and
> the log messages generated by #PF OOPSes.
> 
> This series can also be seen as CET preparation.  CET introduces the
> WRUSS instruction, which is the very first way for CPL 0 code to
> cause a #PF fault with the USER bit set.  Let's get the page fault
> code into shape before we start using WRUSS :)
> 
> Changes from v1:
>   - Rebase on top of tip:x86/mm, now that a bunch of v1 was applied.
>     The only material changes are that 'x86/fault: Check
>     user_mode(regs) when validating a stack extension' is gone
>     because the code it fixed has been deleted and that 'x86/fault:
>     Remove sw_error_code' lost the hunk that changed the same code.
> 
> Andy Lutomirski (5):
>   x86/fault: Remove sw_error_code
>   x86/fault: Don't try to recover from an implicit supervisor access
>   x86/oops: Show the correct CS value in show_regs()
>   x86/fault: Decode page fault OOPSes better
>   x86/vsyscall/64: Use X86_PF constants in the simulated #PF error code
> 
>  arch/x86/entry/vsyscall/vsyscall_64.c |   2 +-
>  arch/x86/kernel/process_64.c          |   5 +-
>  arch/x86/mm/fault.c                   | 144 +++++++++++++++++++-------
>  3 files changed, 108 insertions(+), 43 deletions(-)

All looks good to me,

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>