[PATCH] fs: compat: Remove warning from COMPATIBLE_IOCTL

[Matthias Kaehlcke]

From: Mark Charlebois <charlebm@xxxxxxxxx>

cmd in COMPATIBLE_IOCTL is always a u32, so cast it so there isn't a
warning about an overflow in XFORM.

From: Mark Charlebois <charlebm@xxxxxxxxx>
Signed-off-by: Mark Charlebois <charlebm@xxxxxxxxx>
Signed-off-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
---
Resending https://patchwork.kernel.org/patch/4961631/

 fs/compat_ioctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 11d087b2b28e..6116d5275a3e 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -833,7 +833,7 @@ static int compat_ioctl_preallocate(struct file *file,
  */
 #define XFORM(i) (((i) ^ ((i) << 27) ^ ((i) << 17)) & 0xffffffff)
 
-#define COMPATIBLE_IOCTL(cmd) XFORM(cmd),
+#define COMPATIBLE_IOCTL(cmd) XFORM((u32)cmd),
 /* ioctl should not be warned about even if it's not implemented.
    Valid reasons to use this:
    - It is implemented with ->compat_ioctl on some device, but programs
-- 
2.12.2.715.g7642488e1d-goog