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-rw-r--r--arch/x86/include/asm/uaccess.h19
-rw-r--r--arch/x86/kernel/i386_ksyms_32.c1
-rw-r--r--arch/x86/lib/getuser.S37
3 files changed, 48 insertions, 9 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 1709801d18ec..1e963267d44e 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -151,8 +151,15 @@ extern int __get_user_bad(void);
* On error, the variable @x is set to zero.
*/
#ifdef CONFIG_X86_32
-#define __get_user_8(__ret_gu, __val_gu, ptr) \
- __get_user_x(X, __ret_gu, __val_gu, ptr)
+#define __get_user_8(ret, x, ptr) \
+do { \
+ register unsigned long long __xx asm("%edx"); \
+ asm volatile("call __get_user_8" \
+ : "=a" (ret), "=r" (__xx) \
+ : "0" (ptr)); \
+ (x) = __xx; \
+} while (0)
+
#else
#define __get_user_8(__ret_gu, __val_gu, ptr) \
__get_user_x(8, __ret_gu, __val_gu, ptr)
@@ -162,6 +169,7 @@ extern int __get_user_bad(void);
({ \
int __ret_gu; \
unsigned long __val_gu; \
+ unsigned long long __val_gu8; \
__chk_user_ptr(ptr); \
might_fault(); \
switch (sizeof(*(ptr))) { \
@@ -175,13 +183,16 @@ extern int __get_user_bad(void);
__get_user_x(4, __ret_gu, __val_gu, ptr); \
break; \
case 8: \
- __get_user_8(__ret_gu, __val_gu, ptr); \
+ __get_user_8(__ret_gu, __val_gu8, ptr); \
break; \
default: \
__get_user_x(X, __ret_gu, __val_gu, ptr); \
break; \
} \
- (x) = (__typeof__(*(ptr)))__val_gu; \
+ if (sizeof(*(ptr)) == 8) \
+ (x) = (__typeof__(*(ptr)))__val_gu8; \
+ else \
+ (x) = (__typeof__(*(ptr)))__val_gu; \
__ret_gu; \
})
diff --git a/arch/x86/kernel/i386_ksyms_32.c b/arch/x86/kernel/i386_ksyms_32.c
index 9c3bd4a2050e..0fa69127209a 100644
--- a/arch/x86/kernel/i386_ksyms_32.c
+++ b/arch/x86/kernel/i386_ksyms_32.c
@@ -26,6 +26,7 @@ EXPORT_SYMBOL(csum_partial_copy_generic);
EXPORT_SYMBOL(__get_user_1);
EXPORT_SYMBOL(__get_user_2);
EXPORT_SYMBOL(__get_user_4);
+EXPORT_SYMBOL(__get_user_8);
EXPORT_SYMBOL(__put_user_1);
EXPORT_SYMBOL(__put_user_2);
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 156b9c804670..d3bf9f99ca77 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -15,11 +15,10 @@
* __get_user_X
*
* Inputs: %[r|e]ax contains the address.
- * The register is modified, but all changes are undone
- * before returning because the C code doesn't know about it.
*
* Outputs: %[r|e]ax is error code (0 or -EFAULT)
* %[r|e]dx contains zero-extended value
+ * %ecx contains the high half for 32-bit __get_user_8
*
*
* These functions should not modify any other registers,
@@ -79,22 +78,35 @@ ENTRY(__get_user_4)
CFI_ENDPROC
ENDPROC(__get_user_4)
-#ifdef CONFIG_X86_64
ENTRY(__get_user_8)
CFI_STARTPROC
+#ifdef CONFIG_X86_64
add $7,%_ASM_AX
jc bad_get_user
GET_THREAD_INFO(%_ASM_DX)
cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
- jae bad_get_user
+ jae bad_get_user
ASM_STAC
4: movq -7(%_ASM_AX),%_ASM_DX
xor %eax,%eax
ASM_CLAC
ret
+#else
+ add $7,%_ASM_AX
+ jc bad_get_user_8
+ GET_THREAD_INFO(%_ASM_DX)
+ cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+ jae bad_get_user_8
+ ASM_STAC
+4: mov -7(%_ASM_AX),%edx
+5: mov -3(%_ASM_AX),%ecx
+ xor %eax,%eax
+ ASM_CLAC
+ ret
+#endif
CFI_ENDPROC
ENDPROC(__get_user_8)
-#endif
+
bad_get_user:
CFI_STARTPROC
@@ -105,9 +117,24 @@ bad_get_user:
CFI_ENDPROC
END(bad_get_user)
+#ifdef CONFIG_X86_32
+bad_get_user_8:
+ CFI_STARTPROC
+ xor %edx,%edx
+ xor %ecx,%ecx
+ mov $(-EFAULT),%_ASM_AX
+ ASM_CLAC
+ ret
+ CFI_ENDPROC
+END(bad_get_user_8)
+#endif
+
_ASM_EXTABLE(1b,bad_get_user)
_ASM_EXTABLE(2b,bad_get_user)
_ASM_EXTABLE(3b,bad_get_user)
#ifdef CONFIG_X86_64
_ASM_EXTABLE(4b,bad_get_user)
+#else
+ _ASM_EXTABLE(4b,bad_get_user_8)
+ _ASM_EXTABLE(5b,bad_get_user_8)
#endif