Subject: Re: [PATCH v6 03/10] mm/memory_hotplug: Don't access uninitialized memmaps in shrink_pgdat_span()

From: David Hildenbrand <[email-masked]>
Date: Mon, 14 Oct 2019 11:31:14 +0200

On 06.10.19 10:56, David Hildenbrand wrote:
> We might use the nid of memmaps that were never initialized. For
> example, if the memmap was poisoned, we will crash the kernel in
> pfn_to_nid() right now. Let's use the calculated boundaries of the separate
> zones instead. This now also avoids having to iterate over a whole bunch of
> subsections again, after shrinking one zone.
> 
> Before commit d0dc12e86b31 ("mm/memory_hotplug: optimize memory
> hotplug"), the memmap was initialized to 0 and the node was set to the
> right value. After that commit, the node might be garbage.
> 
> We'll have to fix shrink_zone_span() next.
> 
> Cc: Andrew Morton <[email-masked]>
> Cc: Oscar Salvador <[email-masked]>
> Cc: David Hildenbrand <[email-masked]>
> Cc: Michal Hocko <[email-masked]>
> Cc: Pavel Tatashin <[email-masked]>
> Cc: Dan Williams <[email-masked]>
> Cc: Wei Yang <[email-masked]>
> Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug")

@Andrew, can you convert that to

Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") # visible after d0dc12e86b319

and add

Cc: [email-masked] # v4.13+

-- 

Thanks,

David / dhildenb

_______________________________________________
linux-arm-kernel mailing list
[email-masked]
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel