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Commit fd35fbcd authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

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



Checkin d7acb92f 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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <AANLkTi=RKyHLNTq6iomZOXkc6Zw1j9iAgsq8388XmzwN@mail.gmail.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent f5d9d249

arch/x86/include/asm/i387.h

+24 −0
Original line number Diff line number Diff line
@@ -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;