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

[Boris Ostrovsky]

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.

-boris