On Mon, Oct 2, 2023 at 10:53 AM Nathan Chancellor <nathan@xxxxxxxxxx> 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") > Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> Thanks for the patch! Reviewed-by: Nick Desaulniers <ndesaulniers@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, > -- > Nathan Chancellor <nathan@xxxxxxxxxx> > > -- Thanks, ~Nick Desaulniers
