Commit-ID: b11ca7fbc735aca5ab78ce8130603bbf4fefd3f7
Gitweb: http://git.kernel.org/tip/b11ca7fbc735aca5ab78ce8130603bbf4fefd3f7
Author: Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate: Wed, 20 May 2015 09:59:30 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 20 May 2015 10:02:22 +0200
x86/fpu/xstate: Use explicit parameter in xstate_fault()
While looking at xstate.h it took me some time to realize that
'xstate_fault' uses 'err' as a silent parameter. This is not
obvious at the call site, at all.
Make it an explicit macro argument, so that the syntactic
connection is easier to see. Also explain xstate_fault()
a bit.
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/fpu/xstate.h | 34 ++++++++++++++++++++--------------
1 file changed, 20 insertions(+), 14 deletions(-)
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 8f336d2..a6e07bb 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -47,12 +47,18 @@ extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
#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)
+/* 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
@@ -70,13 +76,13 @@ static inline int copy_xregs_to_kernel_booting(struct xregs_state *fx)
if (boot_cpu_has(X86_FEATURE_XSAVES))
asm volatile("1:"XSAVES"\n\t"
"2:\n\t"
- xstate_fault
+ xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
else
asm volatile("1:"XSAVE"\n\t"
"2:\n\t"
- xstate_fault
+ xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
return err;
@@ -97,13 +103,13 @@ static inline int copy_kernel_to_xregs_booting(struct xregs_state *fx, u64 mask)
if (boot_cpu_has(X86_FEATURE_XSAVES))
asm volatile("1:"XRSTORS"\n\t"
"2:\n\t"
- xstate_fault
+ xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
else
asm volatile("1:"XRSTOR"\n\t"
"2:\n\t"
- xstate_fault
+ xstate_fault(err)
: "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
return err;
@@ -141,7 +147,7 @@ static inline int copy_xregs_to_kernel(struct xregs_state *fx)
[fx] "D" (fx), "a" (lmask), "d" (hmask) :
"memory");
asm volatile("2:\n\t"
- xstate_fault
+ xstate_fault(err)
: "0" (0)
: "memory");
@@ -169,7 +175,7 @@ static inline int copy_kernel_to_xregs(struct xregs_state *fx, u64 mask)
: "memory");
asm volatile("2:\n"
- xstate_fault
+ xstate_fault(err)
: "0" (0)
: "memory");
@@ -201,7 +207,7 @@ static inline int copy_xregs_to_user(struct xregs_state __user *buf)
__asm__ __volatile__(ASM_STAC "\n"
"1:"XSAVE"\n"
"2: " ASM_CLAC "\n"
- xstate_fault
+ xstate_fault(err)
: "D" (buf), "a" (-1), "d" (-1), "0" (0)
: "memory");
return err;
@@ -220,7 +226,7 @@ static inline int copy_user_to_xregs(struct xregs_state __user *buf, u64 mask)
__asm__ __volatile__(ASM_STAC "\n"
"1:"XRSTOR"\n"
"2: " ASM_CLAC "\n"
- xstate_fault
+ xstate_fault(err)
: "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
: "memory"); /* memory required? */
return err;
--
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