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x86/fpu: Move the xstate copying functions into fpu/internal.h
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All the other register<-> memory copying functions are defined
in fpu/internal.h, so move the xstate variants there too.

Beyond being more consistent, this also allows FPU debugging
checks to be added to them. (Because they can now use the
macros defined in fpu/internal.h.)

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Ingo Molnar committed May 25, 2015
1 parent 3152657 commit fd169b0
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Showing 2 changed files with 192 additions and 192 deletions.
192 changes: 192 additions & 0 deletions arch/x86/include/asm/fpu/internal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -208,6 +208,198 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
}
}

/* These macros all use (%edi)/(%rdi) as the single memory argument. */
#define XSAVE ".byte " REX_PREFIX "0x0f,0xae,0x27"
#define XSAVEOPT ".byte " REX_PREFIX "0x0f,0xae,0x37"
#define XSAVES ".byte " REX_PREFIX "0x0f,0xc7,0x2f"
#define XRSTOR ".byte " REX_PREFIX "0x0f,0xae,0x2f"
#define XRSTORS ".byte " REX_PREFIX "0x0f,0xc7,0x1f"

/* xstate instruction fault handler: */
#define xstate_fault(__err) \
\
".section .fixup,\"ax\"\n" \
\
"3: movl $-1,%[err]\n" \
" jmp 2b\n" \
\
".previous\n" \
\
_ASM_EXTABLE(1b, 3b) \
: [err] "=r" (__err)

/*
* This function is called only during boot time when x86 caps are not set
* up and alternative can not be used yet.
*/
static inline int copy_xregs_to_kernel_booting(struct xregs_state *fx)
{
u64 mask = -1;
u32 lmask = mask;
u32 hmask = mask >> 32;
int err = 0;

WARN_ON(system_state != SYSTEM_BOOTING);

if (boot_cpu_has(X86_FEATURE_XSAVES))
asm volatile("1:"XSAVES"\n\t"
"2:\n\t"
xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
else
asm volatile("1:"XSAVE"\n\t"
"2:\n\t"
xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
return err;
}

/*
* This function is called only during boot time when x86 caps are not set
* up and alternative can not be used yet.
*/
static inline int copy_kernel_to_xregs_booting(struct xregs_state *fx, u64 mask)
{
u32 lmask = mask;
u32 hmask = mask >> 32;
int err = 0;

WARN_ON(system_state != SYSTEM_BOOTING);

if (boot_cpu_has(X86_FEATURE_XSAVES))
asm volatile("1:"XRSTORS"\n\t"
"2:\n\t"
xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
else
asm volatile("1:"XRSTOR"\n\t"
"2:\n\t"
xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
return err;
}

/*
* Save processor xstate to xsave area.
*/
static inline int copy_xregs_to_kernel(struct xregs_state *fx)
{
u64 mask = -1;
u32 lmask = mask;
u32 hmask = mask >> 32;
int err = 0;

WARN_ON(!alternatives_patched);

/*
* If xsaves is enabled, xsaves replaces xsaveopt because
* it supports compact format and supervisor states in addition to
* modified optimization in xsaveopt.
*
* Otherwise, if xsaveopt is enabled, xsaveopt replaces xsave
* because xsaveopt supports modified optimization which is not
* supported by xsave.
*
* If none of xsaves and xsaveopt is enabled, use xsave.
*/
alternative_input_2(
"1:"XSAVE,
XSAVEOPT,
X86_FEATURE_XSAVEOPT,
XSAVES,
X86_FEATURE_XSAVES,
[fx] "D" (fx), "a" (lmask), "d" (hmask) :
"memory");
asm volatile("2:\n\t"
xstate_fault(err)
: "0" (0)
: "memory");

return err;
}

/*
* Restore processor xstate from xsave area.
*/
static inline int copy_kernel_to_xregs(struct xregs_state *fx, u64 mask)
{
int err = 0;
u32 lmask = mask;
u32 hmask = mask >> 32;

/*
* Use xrstors to restore context if it is enabled. xrstors supports
* compacted format of xsave area which is not supported by xrstor.
*/
alternative_input(
"1: " XRSTOR,
XRSTORS,
X86_FEATURE_XSAVES,
"D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");

asm volatile("2:\n"
xstate_fault(err)
: "0" (0)
: "memory");

return err;
}

/*
* Save xstate to user space xsave area.
*
* We don't use modified optimization because xrstor/xrstors might track
* a different application.
*
* We don't use compacted format xsave area for
* backward compatibility for old applications which don't understand
* compacted format of xsave area.
*/
static inline int copy_xregs_to_user(struct xregs_state __user *buf)
{
int err;

/*
* Clear the xsave header first, so that reserved fields are
* initialized to zero.
*/
err = __clear_user(&buf->header, sizeof(buf->header));
if (unlikely(err))
return -EFAULT;

__asm__ __volatile__(ASM_STAC "\n"
"1:"XSAVE"\n"
"2: " ASM_CLAC "\n"
xstate_fault(err)
: "D" (buf), "a" (-1), "d" (-1), "0" (0)
: "memory");
return err;
}

/*
* Restore xstate from user space xsave area.
*/
static inline int copy_user_to_xregs(struct xregs_state __user *buf, u64 mask)
{
int err = 0;
struct xregs_state *xstate = ((__force struct xregs_state *)buf);
u32 lmask = mask;
u32 hmask = mask >> 32;

__asm__ __volatile__(ASM_STAC "\n"
"1:"XRSTOR"\n"
"2: " ASM_CLAC "\n"
xstate_fault(err)
: "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
: "memory"); /* memory required? */
return err;
}

/*
* These must be called with preempt disabled. Returns
* 'true' if the FPU state is still intact and we can
Expand Down
192 changes: 0 additions & 192 deletions arch/x86/include/asm/fpu/xstate.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -40,198 +40,6 @@ extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];

extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);

/* These macros all use (%edi)/(%rdi) as the single memory argument. */
#define XSAVE ".byte " REX_PREFIX "0x0f,0xae,0x27"
#define XSAVEOPT ".byte " REX_PREFIX "0x0f,0xae,0x37"
#define XSAVES ".byte " REX_PREFIX "0x0f,0xc7,0x2f"
#define XRSTOR ".byte " REX_PREFIX "0x0f,0xae,0x2f"
#define XRSTORS ".byte " REX_PREFIX "0x0f,0xc7,0x1f"

/* xstate instruction fault handler: */
#define xstate_fault(__err) \
\
".section .fixup,\"ax\"\n" \
\
"3: movl $-1,%[err]\n" \
" jmp 2b\n" \
\
".previous\n" \
\
_ASM_EXTABLE(1b, 3b) \
: [err] "=r" (__err)

/*
* This function is called only during boot time when x86 caps are not set
* up and alternative can not be used yet.
*/
static inline int copy_xregs_to_kernel_booting(struct xregs_state *fx)
{
u64 mask = -1;
u32 lmask = mask;
u32 hmask = mask >> 32;
int err = 0;

WARN_ON(system_state != SYSTEM_BOOTING);

if (boot_cpu_has(X86_FEATURE_XSAVES))
asm volatile("1:"XSAVES"\n\t"
"2:\n\t"
xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
else
asm volatile("1:"XSAVE"\n\t"
"2:\n\t"
xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
return err;
}

/*
* This function is called only during boot time when x86 caps are not set
* up and alternative can not be used yet.
*/
static inline int copy_kernel_to_xregs_booting(struct xregs_state *fx, u64 mask)
{
u32 lmask = mask;
u32 hmask = mask >> 32;
int err = 0;

WARN_ON(system_state != SYSTEM_BOOTING);

if (boot_cpu_has(X86_FEATURE_XSAVES))
asm volatile("1:"XRSTORS"\n\t"
"2:\n\t"
xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
else
asm volatile("1:"XRSTOR"\n\t"
"2:\n\t"
xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
return err;
}

/*
* Save processor xstate to xsave area.
*/
static inline int copy_xregs_to_kernel(struct xregs_state *fx)
{
u64 mask = -1;
u32 lmask = mask;
u32 hmask = mask >> 32;
int err = 0;

WARN_ON(!alternatives_patched);

/*
* If xsaves is enabled, xsaves replaces xsaveopt because
* it supports compact format and supervisor states in addition to
* modified optimization in xsaveopt.
*
* Otherwise, if xsaveopt is enabled, xsaveopt replaces xsave
* because xsaveopt supports modified optimization which is not
* supported by xsave.
*
* If none of xsaves and xsaveopt is enabled, use xsave.
*/
alternative_input_2(
"1:"XSAVE,
XSAVEOPT,
X86_FEATURE_XSAVEOPT,
XSAVES,
X86_FEATURE_XSAVES,
[fx] "D" (fx), "a" (lmask), "d" (hmask) :
"memory");
asm volatile("2:\n\t"
xstate_fault(err)
: "0" (0)
: "memory");

return err;
}

/*
* Restore processor xstate from xsave area.
*/
static inline int copy_kernel_to_xregs(struct xregs_state *fx, u64 mask)
{
int err = 0;
u32 lmask = mask;
u32 hmask = mask >> 32;

/*
* Use xrstors to restore context if it is enabled. xrstors supports
* compacted format of xsave area which is not supported by xrstor.
*/
alternative_input(
"1: " XRSTOR,
XRSTORS,
X86_FEATURE_XSAVES,
"D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");

asm volatile("2:\n"
xstate_fault(err)
: "0" (0)
: "memory");

return err;
}

/*
* Save xstate to user space xsave area.
*
* We don't use modified optimization because xrstor/xrstors might track
* a different application.
*
* We don't use compacted format xsave area for
* backward compatibility for old applications which don't understand
* compacted format of xsave area.
*/
static inline int copy_xregs_to_user(struct xregs_state __user *buf)
{
int err;

/*
* Clear the xsave header first, so that reserved fields are
* initialized to zero.
*/
err = __clear_user(&buf->header, sizeof(buf->header));
if (unlikely(err))
return -EFAULT;

__asm__ __volatile__(ASM_STAC "\n"
"1:"XSAVE"\n"
"2: " ASM_CLAC "\n"
xstate_fault(err)
: "D" (buf), "a" (-1), "d" (-1), "0" (0)
: "memory");
return err;
}

/*
* Restore xstate from user space xsave area.
*/
static inline int copy_user_to_xregs(struct xregs_state __user *buf, u64 mask)
{
int err = 0;
struct xregs_state *xstate = ((__force struct xregs_state *)buf);
u32 lmask = mask;
u32 hmask = mask >> 32;

__asm__ __volatile__(ASM_STAC "\n"
"1:"XRSTOR"\n"
"2: " ASM_CLAC "\n"
xstate_fault(err)
: "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
: "memory"); /* memory required? */
return err;
}

void *get_xsave_addr(struct xregs_state *xsave, int xstate);

#endif

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