[PATCH v2 21/40] sh: fix put_user sparse errors

From: Michael S. Tsirkin
Date: Tue Jan 06 2015 - 10:51:35 EST


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.

Note: this does not suppress any useful sparse checks since caller
assigns x to typeof(*p), which in turn forces all the necessary type
checks.

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
arch/sh/include/asm/uaccess_64.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/sh/include/asm/uaccess_64.h b/arch/sh/include/asm/uaccess_64.h
index 2e07e0f..c01376c 100644
--- a/arch/sh/include/asm/uaccess_64.h
+++ b/arch/sh/include/asm/uaccess_64.h
@@ -59,19 +59,19 @@ do { \
switch (size) { \
case 1: \
retval = __put_user_asm_b((void *)&x, \
- (long)ptr); \
+ (__force long)ptr); \
break; \
case 2: \
retval = __put_user_asm_w((void *)&x, \
- (long)ptr); \
+ (__force long)ptr); \
break; \
case 4: \
retval = __put_user_asm_l((void *)&x, \
- (long)ptr); \
+ (__force long)ptr); \
break; \
case 8: \
retval = __put_user_asm_q((void *)&x, \
- (long)ptr); \
+ (__force long)ptr); \
break; \
default: \
__put_user_unknown(); \
--
MST

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