Re: [PATCH v6] mm: cma: support sysfs

[John Hubbard]

On 3/23/21 8:27 PM, Minchan Kim wrote:
...
> > > +static int __init cma_sysfs_init(void)
> > > +{
> > > +	unsigned int i;
> > > +
> > > +	cma_kobj_root = kobject_create_and_add("cma", mm_kobj);
> > > +	if (!cma_kobj_root)
> > > +		return -ENOMEM;
> > > +
> > > +	for (i = 0; i < cma_area_count; i++) {
> > > +		int err;
> > > +		struct cma *cma;
> > > +		struct cma_kobject *cma_kobj;
> > > +
> > > +		cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
> > > +		if (!cma_kobj) {
> > > +			kobject_put(cma_kobj_root);
> > > +			return -ENOMEM;
> >
> > This leaks little cma_kobj's all over the floor. :)
>
> I thought kobject_put(cma_kobj_root) should deal with it. No?
If this fails when i > 0, there will be cma_kobj instances that
were stashed in the cma_areas[] array. But this code only deletes
the most recently allocated cma_kobj, not anything allocated on
previous iterations of the loop.

thanks,
--
John Hubbard
NVIDIA