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

[Rafael David Tinoco]

On 11/12/18 1:55 PM, Cyrill Gorcunov wrote:
> 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.

Fine for me. It works in armhf.

Tested-by: Rafael David Tinoco <rafael.tinoco@xxxxxxxxxx>

Note: Maybe you should amend the patch and cast "va" in mmap() to avoid:

In file included from proc-self-map-files-002.c:7:
/usr/include/arm-linux-gnueabihf/sys/mman.h:57:14: note: expected âvoid 
*â but argument is of type âlong unsigned intâ
 extern void *mmap (void *__addr, size_t __len, int __prot,

--
Rafael D. Tinoco
Linaro Kernel Validation