Re: s390: runtime warning about pgtables_bytes

[Martin Schwidefsky]

On Thu, 11 Oct 2018 15:02:11 +0200
Martin Schwidefsky <schwidefsky@xxxxxxxxxx> wrote:

> On Thu, 11 Oct 2018 18:04:12 +0800
> Li Wang <liwang@xxxxxxxxxx> wrote:
> 
> > When running s390 system with LTP/cve-2017-17052.c[1], the following BUG is
> > came out repeatedly.
> > I remember this warning start from kernel-4.16.0 and now it still exist in
> > kernel-4.19-rc7.
> > Can anyone take a look?
> > 
> > [ 2678.991496] BUG: non-zero pgtables_bytes on freeing mm: 16384
> > [ 2679.001543] BUG: non-zero pgtables_bytes on freeing mm: 16384
> > [ 2679.002453] BUG: non-zero pgtables_bytes on freeing mm: 16384
> > [ 2679.003256] BUG: non-zero pgtables_bytes on freeing mm: 16384
> > [ 2679.013689] BUG: non-zero pgtables_bytes on freeing mm: 16384
> > [ 2679.024647] BUG: non-zero pgtables_bytes on freeing mm: 16384
> > [ 2679.064408] BUG: non-zero pgtables_bytes on freeing mm: 16384
> > [ 2679.133963] BUG: non-zero pgtables_bytes on freeing mm: 16384
> > 
> > [1]:
> > https://github.com/linux-test-project/ltp/blob/master/testcases/cve/cve-2017-17052.c  
>  
> Confirmed, I see this bug with cvs-2017-17052 on my LPAR as well.
> I'll look into it.
 
Ok, I think I understand the problem now. This is the patch I am testing
right now. It seems to fix the issue, but I had to change common mm
code for it.
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