Commit 9ef8dc16 authored Jan 06, 2015 by Michael S. Tsirkin

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>

parent 9605ce7e

arch/metag/include/asm/uaccess.h

+13 −8

Original line number	Diff line number	Diff line
		@@ -112,13 +112,18 @@ 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(); \
		} \