Re: [PATCH] iommu: fix return error code in iommu_probe_device()

[Yang Yingliang]

On 2020/11/18 6:41, Will Deacon wrote:
> On Tue, Nov 17, 2020 at 07:11:28PM +0800, Yang Yingliang wrote:
> > On 2020/11/17 17:40, Lu Baolu wrote:
> > > On 2020/11/17 10:52, Yang Yingliang wrote:
> > > > If iommu_group_get() failed, it need return error code
> > > > in iommu_probe_device().
> > > >
> > > > Fixes: cf193888bfbd ("iommu: Move new probe_device path...")
> > > > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> > > > Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> > > > ---
> > > >    drivers/iommu/iommu.c | 4 +++-
> > > >    1 file changed, 3 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> > > > index b53446bb8c6b..6f4a32df90f6 100644
> > > > --- a/drivers/iommu/iommu.c
> > > > +++ b/drivers/iommu/iommu.c
> > > > @@ -253,8 +253,10 @@ int iommu_probe_device(struct device *dev)
> > > >            goto err_out;
> > > >          group = iommu_group_get(dev);
> > > > -    if (!group)
> > > > +    if (!group) {
> > > > +        ret = -ENODEV;
> > > Can you please explain why you use -ENODEV here?
> > Before 79659190ee97 ("iommu: Don't take group reference in
> > iommu_alloc_default_domain()"), in
> >
> > iommu_alloc_default_domain(), if group is NULL, it will return -ENODEV.
> Hmm. While I think the patch is ok, I'm not sure it qualifies as a fix.
> Has iommu_probe_device() ever propagated this error? The commit you
> identify in the 'Fixes:' tag doesn't seem to change this afaict.

I think after this commit 439945e74a4b ("iommu: Move default domain 
allocation to iommu_probe_device()"),

iommu_probe_device() won't return error code if group is NULL. I can add 
this fix tag in v2.


> Will
> .