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authorDaniel Vetter <daniel.vetter@ffwll.ch>2013-03-19 09:47:30 +0100
committerDaniel Vetter <daniel.vetter@ffwll.ch>2013-03-19 09:47:30 +0100
commit0d4a42f6bd298e826620585e766a154ab460617a (patch)
tree406d8f7778691d858dbe3e48e4bbb10e99c0a58a /arch/x86/include/asm/uaccess.h
parentd62b4892f3d9f7dd2002e5309be10719d6805b0f (diff)
parenta937536b868b8369b98967929045f1df54234323 (diff)
Merge tag 'v3.9-rc3' into drm-intel-next-queued
Backmerge so that I can merge Imre Deak's coalesced sg entries fixes, which depend upon the new for_each_sg_page introduce in commit a321e91b6d73ed011ffceed384c40d2785cf723b Author: Imre Deak <imre.deak@intel.com> Date: Wed Feb 27 17:02:56 2013 -0800 lib/scatterlist: add simple page iterator The merge itself is just two trivial conflicts: Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'arch/x86/include/asm/uaccess.h')
-rw-r--r--arch/x86/include/asm/uaccess.h55
1 files changed, 21 insertions, 34 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 1709801d18ec..5ee26875baea 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -125,13 +125,12 @@ extern int __get_user_4(void);
extern int __get_user_8(void);
extern int __get_user_bad(void);
-#define __get_user_x(size, ret, x, ptr) \
- asm volatile("call __get_user_" #size \
- : "=a" (ret), "=d" (x) \
- : "0" (ptr)) \
-
-/* Careful: we have to cast the result to the type of the pointer
- * for sign reasons */
+/*
+ * This is a type: either unsigned long, if the argument fits into
+ * that type, or otherwise unsigned long long.
+ */
+#define __inttype(x) \
+__typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
/**
* get_user: - Get a simple variable from user space.
@@ -150,38 +149,26 @@ extern int __get_user_bad(void);
* Returns zero on success, or -EFAULT on error.
* 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)
-#else
-#define __get_user_8(__ret_gu, __val_gu, ptr) \
- __get_user_x(8, __ret_gu, __val_gu, ptr)
-#endif
-
+/*
+ * Careful: we have to cast the result to the type of the pointer
+ * for sign reasons.
+ *
+ * The use of %edx as the register specifier is a bit of a
+ * simplification, as gcc only cares about it as the starting point
+ * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits
+ * (%ecx being the next register in gcc's x86 register sequence), and
+ * %rdx on 64 bits.
+ */
#define get_user(x, ptr) \
({ \
int __ret_gu; \
- unsigned long __val_gu; \
+ register __inttype(*(ptr)) __val_gu asm("%edx"); \
__chk_user_ptr(ptr); \
might_fault(); \
- switch (sizeof(*(ptr))) { \
- case 1: \
- __get_user_x(1, __ret_gu, __val_gu, ptr); \
- break; \
- case 2: \
- __get_user_x(2, __ret_gu, __val_gu, ptr); \
- break; \
- case 4: \
- __get_user_x(4, __ret_gu, __val_gu, ptr); \
- break; \
- case 8: \
- __get_user_8(__ret_gu, __val_gu, ptr); \
- break; \
- default: \
- __get_user_x(X, __ret_gu, __val_gu, ptr); \
- break; \
- } \
- (x) = (__typeof__(*(ptr)))__val_gu; \
+ asm volatile("call __get_user_%P3" \
+ : "=a" (__ret_gu), "=r" (__val_gu) \
+ : "0" (ptr), "i" (sizeof(*(ptr)))); \
+ (x) = (__typeof__(*(ptr))) __val_gu; \
__ret_gu; \
})