linux/arch/x86/include/asm/fpu
Yu-cheng Yu 99aa22d0d8 x86/fpu/xstate: Copy xstate registers directly to the signal frame when compacted format is in use
XSAVES is a kernel instruction and uses a compacted format. When working
with user space, the kernel should provide standard-format, non-supervisor
state data. We cannot do __copy_to_user() from a compacted-format kernel
xstate area to a signal frame.

Dave Hansen proposes this method to simplify copy xstate directly to user.

This patch is based on an earlier patch from Fenghua Yu <fenghua.yu@intel.com>

Originally-from: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c36f419d525517d04209a28dd8e1e5af9000036e.1463760376.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-18 10:10:19 +02:00
..
api.h x86/fpu: Introduce cpu_has_xfeatures(xfeatures_mask, feature_name) 2015-05-19 15:47:55 +02:00
internal.h x86/fpu: Add tracepoints to dump FPU state at key points 2016-06-08 13:33:33 +02:00
regset.h x86/fpu: Factor out fpu/regset.h from fpu/internal.h 2015-05-19 15:48:06 +02:00
signal.h x86/headers: Remove <asm/sigcontext.h> references on the kernel side 2015-09-08 10:06:05 +02:00
types.h x86/fpu, x86/mm/pkeys: Add PKRU xsave fields and data structures 2016-02-16 10:11:14 +01:00
xstate.h x86/fpu/xstate: Copy xstate registers directly to the signal frame when compacted format is in use 2016-06-18 10:10:19 +02:00