Hi Nathan,
On 2/10/23 19:53, Nathan Chancellor wrote:
When building with clang, there is a warning (or error with
CONFIG_WERROR=y) due to a bitwise AND and logical NOT in
vfio_cdx_bm_ctrl():
drivers/vfio/cdx/main.c:77:6: error: logical not is only applied to the left hand side of this bitwise operator [-Werror,-Wlogical-not-parentheses]
77 | if (!vdev->flags & BME_SUPPORT)
| ^ ~
drivers/vfio/cdx/main.c:77:6: note: add parentheses after the '!' to evaluate the bitwise operator first
77 | if (!vdev->flags & BME_SUPPORT)
| ^
| ( )
drivers/vfio/cdx/main.c:77:6: note: add parentheses around left hand side expression to silence this warning
77 | if (!vdev->flags & BME_SUPPORT)
| ^
| ( )
1 error generated.
Add the parentheses as suggested in the first note, which is clearly
what was intended here.
Closes: https://github.com/ClangBuiltLinux/linux/issues/1939
Fixes: 8a97ab9b8b31 ("vfio-cdx: add bus mastering device feature support")
My current /master points to commit ce36c8b14987 which doesn't include
8a97ab9b8b31, so maybe this can be squashed / reordered in the VFIO tree
(where I assume this commit is). That said, the fix is correct, so:
Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
Regards,
Phil.
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---
drivers/vfio/cdx/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/vfio/cdx/main.c b/drivers/vfio/cdx/main.c
index a437630be354..a63744302b5e 100644
--- a/drivers/vfio/cdx/main.c
+++ b/drivers/vfio/cdx/main.c
@@ -74,7 +74,7 @@ static int vfio_cdx_bm_ctrl(struct vfio_device *core_vdev, u32 flags,
struct vfio_device_feature_bus_master ops;
int ret;
- if (!vdev->flags & BME_SUPPORT)
+ if (!(vdev->flags & BME_SUPPORT))
return -ENOTTY;
ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET,
---
base-commit: fcb2f2ed4a80cfe383d87da75caba958516507e9
change-id: 20231002-vfio-cdx-logical-not-parentheses-aca8fbd6b278
Best regards,
