[tip:x86/xsave] x86/xsaves: Define a macro for handling xsave/ xrstor instruction fault

[tip-bot for Fenghua Yu <tipbot@zytor.com>]

Commit-ID:  b84e70552e5aad71a1c14536e6ffcfe7934b73e4
Gitweb:     http://git.kernel.org/tip/b84e70552e5aad71a1c14536e6ffcfe7934b73e4
Author:     Fenghua Yu <fenghua.yu@intel.com>
AuthorDate: Thu, 29 May 2014 11:12:35 -0700
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 29 May 2014 14:31:18 -0700

x86/xsaves: Define a macro for handling xsave/xrstor instruction fault

Define a macro to handle fault generated by xsave, xsaveopt, xsaves, xrstor,
and xrstors instructions. It is used in functions like xsave_state() etc.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1401387164-43416-8-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/include/asm/xsave.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 71bdde4..76c2459 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -58,6 +58,13 @@ extern int init_fpu(struct task_struct *child);
 #define XRSTOR		".byte " REX_PREFIX "0x0f,0xae,0x2f"
 #define XRSTORS		".byte " REX_PREFIX "0x0f,0xc7,0x1f"
 
+#define xstate_fault	".section .fixup,\"ax\"\n"	\
+			"3:  movl $-1,%[err]\n"		\
+			"    jmp  2b\n"			\
+			".previous\n"			\
+			_ASM_EXTABLE(1b, 3b)		\
+			: [err] "=r" (err)
+
 static inline int fpu_xrstor_checking(struct xsave_struct *fx)
 {
 	int err;