x86-64, asm: Use fxsaveq/fxrestorq in more places

Checkin d7acb92fea932ad2e7846480aeacddc2c03c8485 made use of fxsaveq
in fpu_fxsave() if the assembler supports it; this adds
fxsaveq/fxrstorq to fxrstor_checking() and fxsave_user() as well.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <AANLkTi=RKyHLNTq6iomZOXkc6Zw1j9iAgsq8388XmzwN@mail.gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 4aa2bb3b242ab76733e0f7e5ba95454471297c1a..ef328901c80240f4a1471d3e4bdd795daffc6621 100644 (file)
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -93,6 +93,17 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
        int err;
 
        /* See comment in fxsave() below. */
+#ifdef CONFIG_AS_FXSAVEQ
+       asm volatile("1:  fxrstorq %[fx]\n\t"
+                    "2:\n"
+                    ".section .fixup,\"ax\"\n"
+                    "3:  movl $-1,%[err]\n"
+                    "    jmp  2b\n"
+                    ".previous\n"
+                    _ASM_EXTABLE(1b, 3b)
+                    : [err] "=r" (err)
+                    : [fx] "m" (*fx), "0" (0));
+#else
        asm volatile("1:  rex64/fxrstor (%[fx])\n\t"
                     "2:\n"
                     ".section .fixup,\"ax\"\n"
@@ -102,6 +113,7 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
                     _ASM_EXTABLE(1b, 3b)
                     : [err] "=r" (err)
                     : [fx] "R" (fx), "m" (*fx), "0" (0));
+#endif
        return err;
 }
 
@@ -119,6 +131,17 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
                return -EFAULT;
 
        /* See comment in fxsave() below. */
+#ifdef CONFIG_AS_FXSAVEQ
+       asm volatile("1:  fxsaveq %[fx]\n\t"
+                    "2:\n"
+                    ".section .fixup,\"ax\"\n"
+                    "3:  movl $-1,%[err]\n"
+                    "    jmp  2b\n"
+                    ".previous\n"
+                    _ASM_EXTABLE(1b, 3b)
+                    : [err] "=r" (err), [fx] "=m" (*fx)
+                    : "0" (0));
+#else
        asm volatile("1:  rex64/fxsave (%[fx])\n\t"
                     "2:\n"
                     ".section .fixup,\"ax\"\n"
@@ -128,6 +151,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
                     _ASM_EXTABLE(1b, 3b)
                     : [err] "=r" (err), "=m" (*fx)
                     : [fx] "R" (fx), "0" (0));
+#endif
        if (unlikely(err) &&
            __clear_user(fx, sizeof(struct i387_fxsave_struct)))
                err = -EFAULT;