Re: [PATCH 00/10] x86/xsaves: Fix XSAVES known issues

From: Ingo Molnar
Date: Wed Feb 24 2016 - 03:43:44 EST



* Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> wrote:

> XSAVES is a kernel-mode instruction. It offers a compacted format and
> memory-write optimization. These patches fix known issues in the first
> implementation. They are intended for discussion and getting feedback
> before actually getting applied.
>
> Patch 1, 2, and 4 are for converting between kernel-mode xstate area and
> signal frames.
>
> Patch 8 is for converting between kernel-mode xstate area and ptrace
> frames.
>
> Patch 3 and 7 fix optimization issues introduced by XSAVES to the buffer
> init_fpstate.
>
> Patch 5 and 6 are related to xstate component offsets.
>
> Patch 9 fixes xstate area print out.
>
> Patch 10 re-enables XSAVES.
>
> Yu-cheng Yu (10):
> x86/xsaves: Define and use user_xstate_size for xstate size in signal
> context
> x86/xsaves: Rename xstate_size to kernel_xstate_size to explicitly
> distinguish xstate size in kernel from user space
> x86/xsaves: Keep init_fpstate.xsave.header.xfeatures as zero for init
> optimization
> x86/xsaves: Introduce a new check that allows correct xstates copy
> from kernel to user directly
> x86/xsaves: Align xstate components according to CPUID
> x86/xsaves: Supervisor state component offset
> x86/xsaves: Fix init_fpstate.header.xcomp_bv
> x86/xsaves: Fix PTRACE frames for XSAVES
> x86/xsaves: Fix XSTATE component offset print out
> x86/xsaves: Re-enable XSAVES
>
> arch/x86/include/asm/fpu/types.h | 2 +
> arch/x86/include/asm/fpu/xstate.h | 8 +-
> arch/x86/include/asm/processor.h | 3 +-
> arch/x86/kernel/fpu/core.c | 6 +-
> arch/x86/kernel/fpu/init.c | 32 +---
> arch/x86/kernel/fpu/regset.c | 56 ++++--
> arch/x86/kernel/fpu/signal.c | 69 ++++++-
> arch/x86/kernel/fpu/xstate.c | 388 +++++++++++++++++++++++++++++---------
> 8 files changed, 425 insertions(+), 139 deletions(-)

Small housekeeping request: could you please make sure your series is properly
threaded for email clients? This submission was sent as singular patches, without
any References header.

I don't even know how you coaxed git-send-email into doing that - did you use
--no-thread?

The recommended flags are --thread --no-chain-reply-to.

Thanks!

Ingo