Re: [PATCH -mm] vmscan: make mapped executable pages the first class citizen

KOSAKI Motohiro
2009-05-10T12:40:15Z

>> > They always use mmap(PROT_READ | PROT_WRITE | PROT_EXEC) for anycase.
>> > Please google it. you can find various example.
>>
>> How widely is PROT_EXEC abused? Would you share some of your google results?
>
> That's a security bug right there and should be fixed regardless of our
> heuristics.

Yes, should be. but it's not security issue. it doesn't make any security hole.
Plus, this claim doesn't help to solve end-user problems.

I think the basic concept of the patch is right.
- executable mapping is important for good latency
- executable file is relatively small

The last problem is, The patch assume executable mappings is rare, but
it isn't guranteed.
How do we separate truth executable mapping and mis-used PROT_EXEC usage?