Re: [PATCH -next] samples: vfio-mdev: fix error return code in mdpy_fb_probe()

[Dan Carpenter <dan.carpenter@oracle.com>]

On Wed, May 19, 2021 at 09:45:12AM -0600, Alex Williamson wrote:
> On Wed, 19 May 2021 14:15:59 +0000
> Wei Yongjun <weiyongjun1@huawei.com> wrote:
> 
> > Fix to return negative error code -ENOMEM from the error handling
> > case instead of 0, as done elsewhere in this function.
> > 
> > Reported-by: Hulk Robot <hulkci@huawei.com>
> > Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> > ---
> >  samples/vfio-mdev/mdpy-fb.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
> > index 21dbf63d6e41..d4abc0594dbd 100644
> > --- a/samples/vfio-mdev/mdpy-fb.c
> > +++ b/samples/vfio-mdev/mdpy-fb.c
> > @@ -131,8 +131,10 @@ static int mdpy_fb_probe(struct pci_dev *pdev,
> >  		 width, height);
> >  
> >  	info = framebuffer_alloc(sizeof(struct mdpy_fb_par), &pdev->dev);
> > -	if (!info)
> > +	if (!info) {
> > +		ret = -ENOMEM;
> >  		goto err_release_regions;
> > +	}
> >  	pci_set_drvdata(pdev, info);
> >  	par = info->par;
> >  
> > 
> 
> I think there's also a question of why the three 'return -EINVAL;' exit
> paths between here and the prior call to pci_request_regions() don't
> also take this goto.  Thanks,
> 

Smatch catches one of these leaks...  Which is weird that it would
ignore the other error paths.  Perhaps it was intentional?

samples/vfio-mdev/mdpy-fb.c:135 mdpy_fb_probe() warn: missing error code 'ret'
samples/vfio-mdev/mdpy-fb.c:189 mdpy_fb_probe() warn: 'pdev' not released on lines: 120.

regards,
dan carpenter