Re: [PATCH] proc: fixup map_files test on arm

From: Cyrill Gorcunov
Date: Mon Nov 12 2018 - 10:56:10 EST


On Mon, Nov 12, 2018 at 05:14:57PM +0300, Alexey Dobriyan wrote:
...
> > > int main(void)
> > > {
> > > const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
> > > +#ifdef __arm__
> > > + unsigned long va = 2 * PAGE_SIZE;
> > > +#else
> > > + unsigned long va = 0;
> > > +#endif
...
> >
> > I have sent a patch removing proc-self-map-files-002 AND making 001 to use as a
> > HINT for mmap (MAP_FIXED) *at least* *(2 * PAGE_SIZE), which would, likely,
> > attend all architectures, avoiding trying to make the test specific to one,
> > and, still, test the symlinks for issues (like bad chars, spaces, so on).
>
> If the goal is to test the lowest address then going for 2*PAGE_SIZE is
> a mistake.
>
> Which BTW hints to add a test for the highest address.
>
> > Both tests (001 and 002) have pretty much the same code, while they could have 2
> > tests in a single code, using kselftest framework. Is NULL hint + MAP_FIXED
> > something imperative for this test ? Why not to have all in a single test ?
>
> I dislike tests which lump everything together into one process.
>
> > Are you keeping the NULL hint just to test mmap, apart" from the core of
> > this test ?

Guys, lets simply stick with Alexey's patch. I personnally think that
testing mappings should be a separate test in vm/, but seriously this
took too long already :) If Alexey's patch fixes the problem with arm
I think we're fine.