linux/arch/x86/include/asm/fpu
Yu-cheng Yu 1499ce2dd4 x86/fpu/xstate: Fix supervisor xstate component offset
CPUID function 0x0d, sub function (i, i > 1) returns in ebx the offset of
xstate component i. Zero is returned for a supervisor state. A supervisor
state can only be saved by XSAVES and XSAVES uses a compacted format.
There is no fixed offset for a supervisor state. This patch checks and
makes sure a supervisor state offset is not recorded or mis-used. This has
no effect in practice as we currently use no supervisor states, but it
would be good to fix.

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: Josh Poimboeuf <jpoimboe@redhat.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/81b29e40d35d4cec9f2511a856fe769f34935a3f.1466179491.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-10 17:12:10 +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/xstate: Fix supervisor xstate component offset 2016-07-10 17:12:10 +02:00
xstate.h x86/fpu/xstate: Fix supervisor xstate component offset 2016-07-10 17:12:10 +02:00