On Tue, Oct 03, 2023 at 09:40:02AM +0200, Philippe Mathieu-Daudé wrote: > 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: Yes, this is a -next only issue at the moment and I don't mind this change being squashed into the original if Alex rebases his tree (some maintainers don't). > Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx> Thanks a lot for taking a look! Cheers, Nathan > > 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, >
