[PATCH v2] kexec: fix mmap return code handling

[Simon Horman]

On Thu, Nov 26, 2015 at 08:02:35PM +0100, Michael Holzheu wrote:
> On Thu, 26 Nov 2015 19:02:28 +0100
> Petr Tesarik <ptesarik at suse.cz> wrote:
> 
> > On Thu, 26 Nov 2015 18:32:31 +0100
> > Michael Holzheu <holzheu at linux.vnet.ibm.com> wrote:
> > 
> > > Hi Simon again,
> > > 
> > > After a bit more thinking: In theory mmap() could also return NULL.
> > > Therefore the following fix is probably the better one ...
> > 
> > No, if you let the kernel choose the address (i.e. call mmap with NULL
> > addr), it will return at least PAGE_SIZE (and a higher limit is usually
> > enforced by sys.vm.mmap_min_addr sysctl). Admittedly the limit is set
> > in arch-specific code, so theoretically there can be an architecture
> > which sets the limit to 0, but I doubt it, because it would break too
> > many assumptions in user space (for example gcc assumes that
> > dereferencing a NULL pointer terminates a process).
> >
> > In short, this other fix is just as good as the previous one.
> 
> Hi Petr,
> 
> Thanks for clarification! I still would vote for the second one ;-)

Thanks, I have applied that version.