x86: merge getuser.
Merge versions of getuser from uaccess_32.h and uaccess_64.h into
uaccess.h. There is a part which is 64-bit only (for now), and for
that, we use a __get_user_8 macro.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/uaccess.h b/include/asm-x86/uaccess.h
index 2fc30c2..8cb580c 100644
--- a/include/asm-x86/uaccess.h
+++ b/include/asm-x86/uaccess.h
@@ -120,6 +120,61 @@
: "=a" (ret),"=d" (x) \
: "0" (ptr)) \
+/* Careful: we have to cast the result to the type of the pointer
+ * for sign reasons */
+
+/**
+ * get_user: - Get a simple variable from user space.
+ * @x: Variable to store result.
+ * @ptr: Source address, in user space.
+ *
+ * Context: User context only. This function may sleep.
+ *
+ * This macro copies a single simple variable from user space to kernel
+ * space. It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and the result of
+ * dereferencing @ptr must be assignable to @x without a cast.
+ *
+ * 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
+
+#define get_user(x, ptr) \
+({ \
+ int __ret_gu; \
+ unsigned long __val_gu; \
+ __chk_user_ptr(ptr); \
+ 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; \
+ __ret_gu; \
+})
+
+
#ifdef CONFIG_X86_32
# include "uaccess_32.h"
#else