metag: fix put_user sparse errors

virtio wants to write bitwise types to userspace using put_user.
At the moment this triggers sparse errors, since the value is passed
through an integer.

For example:

	__le32 __user *p;
	__le32 x;
	put_user(x, p);

is safe, but currently triggers a sparse warning.

Fix that up using __force.

This also fixes warnings due to writing a pointer out to
userland.

Note: this does not suppress any useful sparse checks since callers
do a cast (__typeof__(*(ptr))) (x) which in turn forces all the
necessary type checks.

Suggested-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: James Hogan <james.hogan@imgtec.com>

diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h
index fd863fe..8282cbc 100644 (file)
--- a/arch/metag/include/asm/uaccess.h
+++ b/arch/metag/include/asm/uaccess.h
@@ -107,18 +107,23 @@ extern long __put_user_asm_w(unsigned int x, void __user *addr);
 extern long __put_user_asm_d(unsigned int x, void __user *addr);
 extern long __put_user_asm_l(unsigned long long x, void __user *addr);
 
-#define __put_user_size(x, ptr, size, retval)                  \
-do {                                                            \
-       retval = 0;                                             \
-       switch (size) {                                         \
+#define __put_user_size(x, ptr, size, retval)                          \
+do {                                                                    \
+       retval = 0;                                                     \
+       switch (size) {                                                 \
        case 1:                                                         \
-               retval = __put_user_asm_b((unsigned int)x, ptr); break; \
+               retval = __put_user_asm_b((__force unsigned int)x, ptr);\
+               break;                                                  \
        case 2:                                                         \
-               retval = __put_user_asm_w((unsigned int)x, ptr); break; \
+               retval = __put_user_asm_w((__force unsigned int)x, ptr);\
+               break;                                                  \
        case 4:                                                         \
-               retval = __put_user_asm_d((unsigned int)x, ptr); break; \
+               retval = __put_user_asm_d((__force unsigned int)x, ptr);\
+               break;                                                  \
        case 8:                                                         \
-               retval = __put_user_asm_l((unsigned long long)x, ptr); break; \
+               retval = __put_user_asm_l((__force unsigned long long)x,\
+                                         ptr);                         \
+               break;                                                  \
        default:                                                        \
                __put_user_bad();                                       \
        }                                                               \