From 1499ce2dd45afddea2e84f9f920890cf88384c4e Mon Sep 17 00:00:00 2001 From: Yu-cheng Yu Date: Fri, 17 Jun 2016 13:07:16 -0700 Subject: 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 Reviewed-by: Dave Hansen Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Quentin Casasnovas Cc: Ravi V. Shankar Cc: Sai Praneeth Prakhya Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/81b29e40d35d4cec9f2511a856fe769f34935a3f.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/fpu/types.h | 1 + arch/x86/include/asm/fpu/xstate.h | 3 +++ 2 files changed, 4 insertions(+) (limited to 'arch/x86/include/asm') diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 36b90bbfc69f..12dd648735b6 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -122,6 +122,7 @@ enum xfeature { #define XFEATURE_MASK_OPMASK (1 << XFEATURE_OPMASK) #define XFEATURE_MASK_ZMM_Hi256 (1 << XFEATURE_ZMM_Hi256) #define XFEATURE_MASK_Hi16_ZMM (1 << XFEATURE_Hi16_ZMM) +#define XFEATURE_MASK_PT (1 << XFEATURE_PT_UNIMPLEMENTED_SO_FAR) #define XFEATURE_MASK_PKRU (1 << XFEATURE_PKRU) #define XFEATURE_MASK_FPSSE (XFEATURE_MASK_FP | XFEATURE_MASK_SSE) diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index d812cf361282..92f376ccc999 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -18,6 +18,9 @@ #define XSAVE_YMM_SIZE 256 #define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET) +/* Supervisor features */ +#define XFEATURE_MASK_SUPERVISOR (XFEATURE_MASK_PT) + /* Supported features which support lazy state saving */ #define XFEATURE_MASK_LAZY (XFEATURE_MASK_FP | \ XFEATURE_MASK_SSE | \ -- cgit v1.2.3