[RFC 1/2] mm, slub: prevent kmalloc_node crashes and memory leaks

[Vlastimil Babka]

On 3/19/20 9:52 AM, Sachin Sant wrote:
> 
>> OK how about this version? It's somewhat ugly, but important is that the fast
>> path case (c->page exists) is unaffected and another common case (c->page is
>> NULL, but node is NUMA_NO_NODE) is just one extra check - impossible to avoid at
>> some point anyway.
>> 
> 
> I attempted the suggested tests.
> 
> Test 1: March 18 linux-next + Patch 1 [1] + Patch  2 [2]
> 
> Machine boots fine. numactl o/p after boot:

Great, thanks! Can I add your Tested-by: then?

If Bharata confirms his scenario with updated patch, I will send it properly.

> # numactl -H
> available: 2 nodes (0-1)
> node 0 cpus:
> node 0 size: 0 MB
> node 0 free: 0 MB
> node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
> node 1 size: 35631 MB
> node 1 free: 32724 MB
> node distances:
> node   0   1
>   0:  10  40
>   1:  40  10
> #
> 
> Test 2: Code base as used in Test 1 + 3 patch series from Srikar [3]
> 
> Machine boots fine. numactl o/p after boot:
> 
> # numactl -H
> available: 1 nodes (1)
> node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
> node 1 size: 35631 MB
> node 1 free: 32711 MB
> node distances:
> node   1
>   1:  10
> #
> 
> Thanks!
> -Sachin
> 
> 
> [1] https://lore.kernel.org/linux-mm/e060ad43-ff4e-0e59-2e64-ce8a4916ec70@suse.cz/T/#mb8d0a358dc5c5fb9661fa45047072a92c510faf2
> [2] https://lore.kernel.org/linux-mm/e060ad43-ff4e-0e59-2e64-ce8a4916ec70@suse.cz/T/#mce342e54a95ce2ee3043901e52d70ee2fd94c516
> [3] https://lore.kernel.org/linux-mm/20200311110237.5731-1-srikar@linux.vnet.ibm.com/
>