On Tue, Mar 15, 2022 at 08:03:26AM -0700, Tom Rix wrote:>
> On 3/15/22 6:28 AM, Michael S. Tsirkin wrote:
> > On Tue, Mar 15, 2022 at 05:41:30AM -0700, trix at redhat.com wrote:
> > > From: Tom Rix <trix at redhat.com>
> > >
> > > Clang static analysis reports this issue
> > > ifcvf_main.c:49:4: warning: Called function
> > > pointer is null (null dereference)
> > > vf->vring->cb.callback(vring->cb.private);
> > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > >
> > > The check
> > > vring = &vf->vring[i];
> > > if (vring->cb.callback)
> > >
> > > Does not match the use. Change dereference so they match.
> > >
> > > Fixes: 79333575b8bd ("vDPA/ifcvf: implement shared IRQ
feature")
> > Thanks a lot! I squashed this into the offending patch - no point in
> > breaking bisect. Pushed to linux. However I'm now
> > having second thoughts about applying that patchset - I'd like
> > soma analysis explaining how this got through testing.
>
> static analysis is something i do treewide.
>
> There are currently ~2500 issues in linux-next, do not panic! many are
false
> positives.
>
> It is pretty easy to setup and once you have a baseline you can filter only
> your files.
>
> Tom
Thanks for that info! I was actually directing this question to the
contributor since the code does not look like it could have ever
worked. I don't have the hardware in question myself.
> > > Signed-off-by: Tom Rix <trix at redhat.com>
> > > ---
> > > drivers/vdpa/ifcvf/ifcvf_main.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c
b/drivers/vdpa/ifcvf/ifcvf_main.c
> > > index 3b48e717e89f7..4366320fb68d3 100644
> > > --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> > > +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> > > @@ -46,7 +46,7 @@ static irqreturn_t
ifcvf_vqs_reused_intr_handler(int irq, void *arg)
> > > for (i = 0; i < vf->nr_vring; i++) {
> > > vring = &vf->vring[i];
> > > if (vring->cb.callback)
> > > - vf->vring->cb.callback(vring->cb.private);
> > > + vring->cb.callback(vring->cb.private);
> > > }
> > > return IRQ_HANDLED;
> > > --
> > > 2.26.3