x86: some lock annotations for user copy paths, v3

- add annotation back to clear_user()
- change probe_kernel_address() to _inatomic*() method
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/lib/usercopy_32.c

@@ -148,6 +148,7 @@ do {									\
 unsigned long
 clear_user(void __user *to, unsigned long n)
 {
+	might_fault();
 	if (access_ok(VERIFY_WRITE, to, n))
 		__do_clear_user(to, n);
 	return n;

include/asm-x86/uaccess.h

@@ -267,7 +267,6 @@ extern void __put_user_8(void);
 #define __put_user_size(x, ptr, size, retval, errret)			\
 do {									\
 	retval = 0;							\
-	might_fault();							\
 	__chk_user_ptr(ptr);						\
 	switch (size) {							\
 	case 1:								\
@@ -320,7 +319,6 @@ do {									\
 #define __get_user_size(x, ptr, size, retval, errret)			\
 do {									\
 	retval = 0;							\
-	might_fault();							\
 	__chk_user_ptr(ptr);						\
 	switch (size) {							\
 	case 1:								\

include/linux/uaccess.h

@@ -78,7 +78,7 @@ static inline unsigned long __copy_from_user_nocache(void *to,
 							\
 		set_fs(KERNEL_DS);			\
 		pagefault_disable();			\
-		ret = __get_user(retval, (__force typeof(retval) __user *)(addr));		\
+		ret = __copy_from_user_inatomic((__force typeof(retval) __user *)(addr), &(retval), sizeof(retval));		\
 		pagefault_enable();			\
 		set_fs(old_fs);				\
 		ret;					\