Re: [PATCH v2 2/3] mm/sparse: fix possible memory leak

[David Rientjes <rientjes@google.com>]

On Thu, 28 Jun 2012, Gavin Shan wrote:

> >> +{
> >> +	unsigned long size = SECTIONS_PER_ROOT *
> >> +			     sizeof(struct mem_section);
> >> +
> >> +	if (!section)
> >> +		return;
> >> +
> >> +	if (slab_is_available())
> >> +		kfree(section);
> >> +	else
> >> +		free_bootmem_node(NODE_DATA(nid),
> >> +			virt_to_phys(section), size);
> >
> >Did you check what happens here if !node_state(nid, N_HIGH_MEMORY)?
> >
> 
> I'm sorry that I'm not catching your point. Please explain for more
> if necessary.
> 

I'm asking specifically about the free_bootmem_node(NODE_DATA(nid), ...).

If this section was allocated in sparse_index_alloc() before 
slab_is_available() with alloc_bootmem_node() and nid is not in 
N_HIGH_MEMORY, will alloc_bootmem_node() fallback to any node or return 
NULL?

If it falls back to any node, is it safe to try to free that section by 
passing NODE_DATA(nid) here when it wasn't allocated on that nid?

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