Re: [PATCH] proc: fix and merge proc-self-map-file tests

[Rafael David Tinoco]

On Sat, Nov 10, 2018, at 3:47 PM, Alexey Dobriyan wrote:
> On Fri, Nov 09, 2018 at 09:30:36AM -0200, Rafael David Tinoco wrote:
> > Merge proc-self-map-files tests into one since this test should focus in
> > testing readlink in /proc/self/map_files/* only, and not trying to test
> > mapping virtual address 0.
> > 
> > Lowest virtual address for user space mapping in other architectures,
> > like arm, is *at least* *(PAGE_SIZE * 2) and NULL hint does not
> > guarantee that when MAP_FIXED flag, important to this test, is given.
> > This patch also fixes this issue in remaining test.
> 
> > -	p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE, fd, 0);
> > +	p = mmap((void *) (2 * PAGE_SIZE), PAGE_SIZE, PROT_NONE,
> 
> I don't know ARM. Is this 2 page limitation a limitation of hardware or
> kernel's?

Kernel:
https://bugs.linaro.org/show_bug.cgi?id=3782#c7