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.
Version 3 adds a WARN_ONCE() in patch 9 to make it clear XSAVES supervisor
states are not yet supported.
Version 2 fixes a mistake in handling supervisor states of ptrace function
copyin_to_xsaves() and some coding style/naming issues in the first version.
It also limits XSAVES only to 64-bit kernel in patch 9.
Patch 1, 2, and 4 are for converting between kernel-mode xstate area and
signal frames.
Patch 3 fixes optimization issues introduced by XSAVES to the buffer
init_fpstate.
Patch 5 and 6 are related to xstate component offsets.
Patch 7 is for converting between kernel-mode xstate area and ptrace
frames.
Patch 8 fixes xstate area print out.
Patch 9 re-enables XSAVES.
Yu-cheng Yu (9):
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 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 | 35 ++--
arch/x86/kernel/fpu/regset.c | 56 ++++--
arch/x86/kernel/fpu/signal.c | 69 ++++++-
arch/x86/kernel/fpu/xstate.c | 400 +++++++++++++++++++++++++++++---------
8 files changed, 443 insertions(+), 136 deletions(-)
--
1.9.1
