Re: [PATCH v2 0/2] mm,fork,security: introduce MADV_WIPEONFORK

[Colm MacCÃrthaigh]

On Tue, Aug 8, 2017 at 5:46 PM, Rik van Riel <riel@xxxxxxxxxx> wrote:

>> If the use case is fairly specific, then perhaps it makes sense to
>> make MADV_WIPEONFORK not applicable (EINVAL) for mappings where the
>> result is 'questionable'.
>
> That would be a question for Florian and Colm.
>
> If they are OK with MADV_WIPEONFORK only working on
> anonymous VMAs (no file mapping), that certainly could
> be implemented.

Anonymous would be sufficient for all of the Crypto-cases that I've
come across. But I can imagine someone wanting to initialize all
application state from a saved file, or share it between processes.

The comparable minherit call sidesteps all of this by simply
documenting that it results in a new anonymous page after fork, and so
the previous state doesn't matter.

Maybe the problem here is the poor name (my fault). WIPEONFORK
suggests an action being taken ... like a user might think that it
literally zeroes a file, for example.  At the risk of bike shedding:
maybe ZEROESONFORK would resolve that small ambiguity?

-- 
Colm