[dpdk-dev] [PATCH] eal/linux: fix memory allocations in containers+SELinux

[Burakov, Anatoly]

On 17-Sep-20 2:47 PM, David Marchand wrote:
> On Fri, Sep 11, 2020 at 2:46 PM Burakov, Anatoly
> <anatoly.burakov at intel.com> wrote:
>>> Removing hugepage files is done in multiple places and the memory
>>> allocation code is complex.
>>> This fix tries to do the minimum and avoids touching other paths.
>>>
>>> If trying to remove the hugepage file before allocating a page fails,
>>> the error is reported to the caller and the user will see a memory
>>> allocation error log.
>>>
>>> Fixes: 582bed1e1d1d ("mem: support mapping hugepages at runtime")
>>> Cc: stable at dpdk.org
>>>
>>> Signed-off-by: David Marchand <david.marchand at redhat.com>
>>> ---
>>
>> I believe only the primary will try to allocate new pages, but this only
>> covers the page-per-file scenario. There's also legacy mem option (which
>> would attempt to remove files prior to creating new ones - not sure if
>> it's refused in that case), and single file segments option (which will
>> mostly fallocate holes rather than delete files, but may still attempt
>> to delete files - by the way, how does fallocate work with SELinux?).
> 
> This issue should only concern part of the memory allocator that deals
> with "named files" backed hugepages.
> I would focus on the code relying on eal_get_hugefile_path() and I
> agree I might have missed the legacy-mem part.
> 
> For anonymous hugepages this should not matter.
> 
> 

Anonymous hugepages shouldn't matter, yes, but single-file segments mode 
does fallocate() and remove - you have the remove part covered, but i'm 
just curious if fallocate() would also cause any issues with SELinux.

-- 
Thanks,
Anatoly