Re: [PATCH v5 0/8] xen: dma-buf support for grant device

[Oleksandr Andrushchenko]

On 07/23/2018 06:22 PM, Boris Ostrovsky wrote:
> On 07/23/2018 09:26 AM, Oleksandr Andrushchenko wrote:
> > On 07/23/2018 11:38 AM, Oleksandr Andrushchenko wrote:
> > > > data/upstream/linux-xen/drivers/xen/gntdev-dmabuf.c: In function
> > > > âgntdev_ioctl_dmabuf_exp_from_refsâ:
> > > > /data/upstream/linux-xen/drivers/xen/gntdev-dmabuf.c:503:6: warning:
> > > > âargs.fdâ may be used uninitialized in this function
> > > > [-Wmaybe-uninitialized]
> > > >  ÂÂ *fd = args.fd;
> > > >  ÂÂ ~~~~^~~~~~~~~
> > > > /data/upstream/linux-xen/drivers/xen/gntdev-dmabuf.c:467:35: note:
> > > > âargs.fdâ was declared here
> > > >  ÂÂ struct gntdev_dmabuf_export_args args;
> > > >  ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ ^~~~
> > > Strangely, but my i386 build goes smooth.
> > > Which version of gcc you use and could you please give me your
> > > .config, so I can test the same?
> > Now I see this warning which seems to be a false positive.
> > Boris, could you please apply the following:
> >
> > diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c
> > index e4c9f1f74476..0680dbcba616 100644
> > --- a/drivers/xen/gntdev-dmabuf.c
> > +++ b/drivers/xen/gntdev-dmabuf.c
> > @@ -495,6 +495,7 @@ static int dmabuf_exp_from_refs(struct gntdev_priv
> > *priv, int flags,
> >  ÂÂÂÂÂÂÂ args.dmabuf_priv = priv->dmabuf_priv;
> >  ÂÂÂÂÂÂÂ args.count = map->count;
> >  ÂÂÂÂÂÂÂ args.pages = map->pages;
> > +ÂÂÂÂÂÂ args.fd = -1;
> >
> >  ÂÂÂÂÂÂÂ ret = dmabuf_exp_from_pages(&args);
> >  ÂÂÂÂÂÂÂ if (ret < 0)
> >
> > or please let me know if you want me to resend with this fix?
>
> Missed this message. Yes, this obviously fixes the problem. And it is
> due to the code fragment that I mentioned in the earlier response.
>
> Which patch is this for? I can add this when committing.
Thank you, this is for "[PATCH v5 7/8] xen/gntdev: Implement dma-buf 
export functionality"
> -boris
Thank you,
Oleksandr