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

From: Yu-cheng Yu
Date: Mon Feb 22 2016 - 13:58:49 EST


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(-)

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1.9.1