x86, fpu: Consolidate inline asm routines for saving/restoring fpu state (0ca5bd0d) · Commits · e / devices / android_kernel_teracube_2e

arch/x86/include/asm/fpu-internal.h

+77 −107

Original line number	Original line	Diff line number	Diff line
	@@ -97,34 +97,24 @@ static inline void sanitize_i387_state(struct task_struct *tsk)
	__sanitize_i387_state(tsk);		__sanitize_i387_state(tsk);
	}		}

	#ifdef CONFIG_X86_64		#define check_insn(insn, output, input...) \
	static inline int fxrstor_checking(struct i387_fxsave_struct *fx)		({ \
	{		int err; \
	int err;		asm volatile("1:" #insn "\n\t" \
			"2:\n" \
	/* See comment in fxsave() below. */		".section .fixup,\"ax\"\n" \
	#ifdef CONFIG_AS_FXSAVEQ		"3: movl $-1,%[err]\n" \
	asm volatile("1: fxrstorq %[fx]\n\t"		" jmp 2b\n" \
	"2:\n"		".previous\n" \
	".section .fixup,\"ax\"\n"		_ASM_EXTABLE(1b, 3b) \
	"3: movl $-1,%[err]\n"		: [err] "=r" (err), output \
	" jmp 2b\n"		: "0"(0), input); \
	".previous\n"		err; \
	_ASM_EXTABLE(1b, 3b)		})
	: [err] "=r" (err)
	: [fx] "m" (*fx), "0" (0));		static inline int fsave_user(struct i387_fsave_struct __user *fx)
	#else		{
	asm volatile("1: rex64/fxrstor (%[fx])\n\t"		return check_insn(fnsave %[fx]; fwait, [fx] "=m" (fx), "m" (fx));
	"2:\n"
	".section .fixup,\"ax\"\n"
	"3: movl $-1,%[err]\n"
	" jmp 2b\n"
	".previous\n"
	_ASM_EXTABLE(1b, 3b)
	: [err] "=r" (err)
	: [fx] "R" (fx), "m" (*fx), "0" (0));
	#endif
	return err;
	}		}

	static inline int fxsave_user(struct i387_fxsave_struct __user *fx)		static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
	@@ -140,61 +130,66 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
	if (unlikely(err))		if (unlikely(err))
	return -EFAULT;		return -EFAULT;

	/* See comment in fxsave() below. */		if (config_enabled(CONFIG_X86_32))
	#ifdef CONFIG_AS_FXSAVEQ		return check_insn(fxsave %[fx], [fx] "=m" (fx), "m" (fx));
	asm volatile("1: fxsaveq %[fx]\n\t"		else if (config_enabled(CONFIG_AS_FXSAVEQ))
	"2:\n"		return check_insn(fxsaveq %[fx], [fx] "=m" (fx), "m" (fx));
	".section .fixup,\"ax\"\n"
	"3: movl $-1,%[err]\n"		/* See comment in fpu_fxsave() below. */
	" jmp 2b\n"		return check_insn(rex64/fxsave (%[fx]), "=m" (*fx), [fx] "R" (fx));
	".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"
	"3: movl $-1,%[err]\n"
	" jmp 2b\n"
	".previous\n"
	_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;
	/* No need to clear here because the caller clears USED_MATH */
	return err;
	}		}

	static inline void fpu_fxsave(struct fpu *fpu)		static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
	{		{
	/* Using "rex64; fxsave %0" is broken because, if the memory operand		if (config_enabled(CONFIG_X86_32))
	uses any extended registers for addressing, a second REX prefix		return check_insn(fxrstor %[fx], "=m" (fx), [fx] "m" (fx));
	will be generated (to the assembler, rex64 followed by semicolon		else if (config_enabled(CONFIG_AS_FXSAVEQ))
	is a separate instruction), and hence the 64-bitness is lost. */		return check_insn(fxrstorq %[fx], "=m" (fx), [fx] "m" (fx));

	#ifdef CONFIG_AS_FXSAVEQ		/* See comment in fpu_fxsave() below. */
	/* Using "fxsaveq %0" would be the ideal choice, but is only supported		return check_insn(rex64/fxrstor (%[fx]), "=m" (*fx), [fx] "R" (fx),
	starting with gas 2.16. */		"m" (*fx));
	__asm__ __volatile__("fxsaveq %0"		}
	: "=m" (fpu->state->fxsave));
	#else		static inline int frstor_checking(struct i387_fsave_struct *fx)
	/* Using, as a workaround, the properly prefixed form below isn't		{
	accepted by any binutils version so far released, complaining that		return check_insn(frstor %[fx], "=m" (fx), [fx] "m" (fx));
	the same type of prefix is used twice if an extended register is		}
	needed for addressing (fix submitted to mainline 2005-11-21).
	asm volatile("rex64/fxsave %0"		static inline void fpu_fxsave(struct fpu *fpu)
	: "=m" (fpu->state->fxsave));		{
	This, however, we can work around by forcing the compiler to select		if (config_enabled(CONFIG_X86_32))
	an addressing mode that doesn't require extended registers. */		asm volatile( "fxsave %[fx]" : [fx] "=m" (fpu->state->fxsave));
			else if (config_enabled(CONFIG_AS_FXSAVEQ))
			asm volatile("fxsaveq %0" : "=m" (fpu->state->fxsave));
			else {
			/* Using "rex64; fxsave %0" is broken because, if the memory
			* operand uses any extended registers for addressing, a second
			* REX prefix will be generated (to the assembler, rex64
			* followed by semicolon is a separate instruction), and hence
			* the 64-bitness is lost.
			*
			* Using "fxsaveq %0" would be the ideal choice, but is only
			* supported starting with gas 2.16.
			*
			* Using, as a workaround, the properly prefixed form below
			* isn't accepted by any binutils version so far released,
			* complaining that the same type of prefix is used twice if
			* an extended register is needed for addressing (fix submitted
			* to mainline 2005-11-21).
			*
			* asm volatile("rex64/fxsave %0" : "=m" (fpu->state->fxsave));
			*
			* This, however, we can work around by forcing the compiler to
			* select an addressing mode that doesn't require extended
			* registers.
			*/
	asm volatile( "rex64/fxsave (%[fx])"		asm volatile( "rex64/fxsave (%[fx])"
	: "=m" (fpu->state->fxsave)		: "=m" (fpu->state->fxsave)
	: [fx] "R" (&fpu->state->fxsave));		: [fx] "R" (&fpu->state->fxsave));
	#endif
	}		}
			}
			#ifdef CONFIG_X86_64

	int ia32_setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,		int ia32_setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
	compat_sigset_t set, struct pt_regs regs);		compat_sigset_t set, struct pt_regs regs);
	@@ -203,28 +198,6 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,

	#else /* CONFIG_X86_32 */		#else /* CONFIG_X86_32 */

	/* perform fxrstor iff the processor has extended states, otherwise frstor */
	static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
	{
	/*
	* The "nop" is needed to make the instructions the same
	* length.
	*/
	alternative_input(
	"nop ; frstor %1",
	"fxrstor %1",
	X86_FEATURE_FXSR,
	"m" (*fx));

	return 0;
	}

	static inline void fpu_fxsave(struct fpu *fpu)
	{
	asm volatile("fxsave %[fx]"
	: [fx] "=m" (fpu->state->fxsave));
	}

	#define ia32_setup_frame __setup_frame		#define ia32_setup_frame __setup_frame
	#define ia32_setup_rt_frame __setup_rt_frame		#define ia32_setup_rt_frame __setup_rt_frame

	@@ -272,17 +245,14 @@ static inline int __save_init_fpu(struct task_struct *tsk)
	return fpu_save_init(&tsk->thread.fpu);		return fpu_save_init(&tsk->thread.fpu);
	}		}

	static inline int fpu_fxrstor_checking(struct fpu *fpu)
	{
	return fxrstor_checking(&fpu->state->fxsave);
	}

	static inline int fpu_restore_checking(struct fpu *fpu)		static inline int fpu_restore_checking(struct fpu *fpu)
	{		{
	if (use_xsave())		if (use_xsave())
	return fpu_xrstor_checking(fpu);		return fpu_xrstor_checking(&fpu->state->xsave);
			else if (use_fxsr())
			return fxrstor_checking(&fpu->state->fxsave);
	else		else
	return fpu_fxrstor_checking(fpu);		return frstor_checking(&fpu->state->fsave);
	}		}

	static inline int restore_fpu_checking(struct task_struct *tsk)		static inline int restore_fpu_checking(struct task_struct *tsk)

arch/x86/include/asm/xsave.h

+1 −5

Original line number	Original line	Diff line number	Diff line
	@@ -42,9 +42,8 @@ extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
	void __user *fpstate,		void __user *fpstate,
	struct _fpx_sw_bytes *sw);		struct _fpx_sw_bytes *sw);

	static inline int fpu_xrstor_checking(struct fpu *fpu)		static inline int fpu_xrstor_checking(struct xsave_struct *fx)
	{		{
	struct xsave_struct *fx = &fpu->state->xsave;
	int err;		int err;

	asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"		asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
	@@ -84,9 +83,6 @@ static inline int xsave_user(struct xsave_struct __user *buf)
	: [err] "=r" (err)		: [err] "=r" (err)
	: "D" (buf), "a" (-1), "d" (-1), "0" (0)		: "D" (buf), "a" (-1), "d" (-1), "0" (0)
	: "memory");		: "memory");
	if (unlikely(err) && __clear_user(buf, xstate_size))
	err = -EFAULT;
	/* No need to clear here because the caller clears USED_MATH */
	return err;		return err;
	}		}

arch/x86/kernel/xsave.c

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -176,8 +176,10 @@ int save_i387_xstate(void __user *buf)
	else		else
	err = fxsave_user(buf);		err = fxsave_user(buf);

	if (err)		if (unlikely(err)) {
			__clear_user(buf, xstate_size);
	return err;		return err;
			}
	user_fpu_end();		user_fpu_end();
	} else {		} else {
	sanitize_i387_state(tsk);		sanitize_i387_state(tsk);