Re: [PATCH] selftest/mm: fix pointer comparison in mremap_test

[Ankit Khushwaha <ankitkhushwaha.linux@gmail.com>]

On Thu, Nov 06, 2025 at 12:18:57PM +0100, David Hildenbrand (Red Hat) wrote:
> On 06.11.25 11:49, Ankit Khushwaha wrote:
> > Pointer arthemitic with 'void * addr' and 'unsigned long long dest_alignment'
> > triggers following warning:
> > 
> > mremap_test.c:1035:31: warning: pointer comparison always evaluates to
> > false [-Wtautological-compare]
> >   1035 |                 if (addr + c.dest_alignment < addr) {
> >        |                                             ^
> > 
> > typecasting 'addr' to 'unsigned long long' to fix pointer comparison.
> 
> With which compiler are you seeing this?

Hi David,

clang version 20.1.8 (Fedora 20.1.8-4.fc42) raised this warning.

To reproduce:
	make -C tools/testing/selftests/mm CC=clang

Thanks,
-- 
Ankit