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authorMichal Simek <monstr@monstr.eu>2010-03-08 10:52:24 +0100
committerMichal Simek <monstr@monstr.eu>2010-04-01 08:38:22 +0200
commit3a6d77245efe062993284fd1c2f7510d9a90efe1 (patch)
tree8ac06ff35d012d905fc82c38af5f6ab42cd43eb9 /arch/microblaze/include/asm/uaccess.h
parentmicroblaze: uaccess: fix clear_user for noMMU kernel (diff)
downloadlinux-3a6d77245efe062993284fd1c2f7510d9a90efe1.tar.xz
linux-3a6d77245efe062993284fd1c2f7510d9a90efe1.zip
microblaze: uaccess: Fix get_user macro for noMMU
Use unified version. Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to '')
-rw-r--r--arch/microblaze/include/asm/uaccess.h89
1 files changed, 66 insertions, 23 deletions
diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index 1af92025fff9..b079ac31a671 100644
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -146,31 +146,75 @@ static inline unsigned long __must_check clear_user(void __user *to,
#ifndef CONFIG_MMU
-/* Undefined function to trigger linker error */
-extern int bad_user_access_length(void);
+extern long __user_bad(void);
+
+#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
+({ \
+ __asm__ __volatile__ ( \
+ "1:" insn " %1, %2, r0;" \
+ " addk %0, r0, r0;" \
+ "2: " \
+ __FIXUP_SECTION \
+ "3: brid 2b;" \
+ " addik %0, r0, %3;" \
+ ".previous;" \
+ __EX_TABLE_SECTION \
+ ".word 1b,3b;" \
+ ".previous;" \
+ : "=&r"(__gu_err), "=r"(__gu_val) \
+ : "r"(__gu_ptr), "i"(-EFAULT) \
+ ); \
+})
+
+/**
+ * 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.
+ */
+
+#define __get_user(x, ptr) \
+({ \
+ unsigned long __gu_val; \
+ /*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \
+ long __gu_err; \
+ switch (sizeof(*(ptr))) { \
+ case 1: \
+ __get_user_asm("lbu", (ptr), __gu_val, __gu_err); \
+ break; \
+ case 2: \
+ __get_user_asm("lhu", (ptr), __gu_val, __gu_err); \
+ break; \
+ case 4: \
+ __get_user_asm("lw", (ptr), __gu_val, __gu_err); \
+ break; \
+ default: \
+ /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
+ } \
+ x = (__typeof__(*(ptr))) __gu_val; \
+ __gu_err; \
+})
+
-/* FIXME this is function for optimalization -> memcpy */
-#define __get_user(var, ptr) \
-({ \
- int __gu_err = 0; \
- switch (sizeof(*(ptr))) { \
- case 1: \
- case 2: \
- case 4: \
- (var) = *(ptr); \
- break; \
- case 8: \
- memcpy((void *) &(var), (ptr), 8); \
- break; \
- default: \
- (var) = 0; \
- __gu_err = __get_user_bad(); \
- break; \
- } \
- __gu_err; \
+#define get_user(x, ptr) \
+({ \
+ access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \
+ ? __get_user((x), (ptr)) : -EFAULT; \
})
-#define __get_user_bad() (bad_user_access_length(), (-EFAULT))
+/* Undefined function to trigger linker error */
+extern int bad_user_access_length(void);
/* FIXME is not there defined __pu_val */
#define __put_user(var, ptr) \
@@ -197,7 +241,6 @@ extern int bad_user_access_length(void);
#define __put_user_bad() (bad_user_access_length(), (-EFAULT))
#define put_user(x, ptr) __put_user((x), (ptr))
-#define get_user(x, ptr) __get_user((x), (ptr))
#define copy_to_user(to, from, n) (memcpy((to), (from), (n)), 0)
#define copy_from_user(to, from, n) (memcpy((to), (from), (n)), 0)