Re: [PATCH 02/18] mm: make vm_mmap killable

[Vlastimil Babka]

On 03/11/2016 01:12 PM, Michal Hocko wrote:
> On Fri 11-03-16 10:59:30, Vlastimil Babka wrote:
> > On 02/29/2016 02:26 PM, Michal Hocko wrote:
> > >From: Michal Hocko <mhocko@xxxxxxxx>
> > >
> > >All the callers of vm_mmap seem to check for the failure already
> > >and bail out in one way or another on the error which means that
> >
> > Hmm I'm not that sure about this one:
> >   17   1071  fs/binfmt_elf.c <<load_elf_binary>>
> >
> > Assigns result of vm_mmap() to "error" variable which is never checked.
>
> Yes it is not checked but not used either. If the current got killed
> then it wouldn't return to the userspace so my understanding is that not
> checking this value is not a problem. At least that is my understanding.

Hmm, that's true. So,

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

> > Shouldn't __must_check trigger here?
>
> well, __must_check is a misleading name. It doesn't actually enforce the
> value is checked. It just has to be used and an assignment is
> sufficient. I was discussing this without our gcc guy and he promissed
> to look and try to come up with a different attribute which would
> actually work like __must_check.

OK!