[PATCH v2 17/40] arm: fix put_user sparse errors
From: mst@redhat.com (Michael S. Tsirkin)
Date: 2015-01-06 15:45:24
Also in:
linux-arch, lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
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@redhat.com> --- arch/arm/include/asm/uaccess.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 4767eb9..74fcde7 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h@@ -413,14 +413,14 @@ do { \ #ifndef __ARMEB__ #define __put_user_asm_half(x,__pu_addr,err) \ ({ \ - unsigned long __temp = (unsigned long)(x); \ + unsigned long __temp = (__force unsigned long)(x); \ __put_user_asm_byte(__temp, __pu_addr, err); \ __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \ }) #else #define __put_user_asm_half(x,__pu_addr,err) \ ({ \ - unsigned long __temp = (unsigned long)(x); \ + unsigned long __temp = (__force unsigned long)(x); \ __put_user_asm_byte(__temp >> 8, __pu_addr, err); \ __put_user_asm_byte(__temp, __pu_addr + 1, err); \ })
--
MST