Re: Re: [linux-next:master 8777/13479] mm/hugetlb.c:3095:39: warning: array subscript 4294967295 is above array bounds of 'struct list_head[1]'

On Fri, Aug 07, 2026 at 07:46:30PM +0800, Muchun Song wrote:
> On Fri, Aug 7, 2026 at 7:37 AM Andrew Morton <[email protected]> wrote:
> >
> > On Fri, 07 Aug 2026 05:01:04 +0800 kernel test robot <[email protected]> wrote:
> >
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > head:   ea2bff00da89d7767d677bb68470130ba96f4928
> > > commit: 20549ccf4da49ff6dcb35ffc741f92aa92e07aeb [8777/13479] mm/hugetlb: free cross-zone bootmem gigantic pages after allocation
> > > config: parisc-randconfig-002-20260807 (https://download.01.org/0day-ci/archive/20260807/[email protected]/config)
> > > compiler: hppa-linux-gcc (GCC) 8.5.0
> >
> > Such an old compiler.
> >
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260807/[email protected]/reproduce)
> > >
> > > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <[email protected]>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > >
> > > All warnings (new ones prefixed by >>):
> > >
> > >    mm/hugetlb.c: In function 'alloc_bootmem_huge_page':
> > > >> mm/hugetlb.c:3095:39: warning: array subscript 4294967295 is above array bounds of 'struct list_head[1]' [-Warray-bounds]
> > >        list_add(&m->list, &huge_boot_pages[nid_request]);
> > >                            ~~~~~~~~~~~~~~~^~~~~~~~~~~~~
> > >    In file included from mm/hugetlb.c:6:
> > > >> include/linux/list.h:163:12: warning: array subscript -1 is below array bounds of 'struct list_head[1]' [-Warray-bounds]
> > >      new->prev = prev;
> > >      ~~~~~~~~~~^~~~~~
> >
> > Well crap, that patch has been in there since June 12.
> 
> This isn't the first report. This is the second time we've had the
> exact same report,
> see [1]. Interestingly, the GCC versions are all the same (8.5.0), so
> I think this must
> be a GCC issue.

Thanks for the info, we will configure the bot to avoid sending such
report again.

> 
> https://lore.kernel.org/all/[email protected]/
> 
> Muchun,
> Thanks.
> 
> >
> > I can't reproduce it with the provided config and hppa-linux gcc-16.1.0.
> >
> > Muchun, I'd be inclined to pretend we never saw this.  But if you want
> > to address it, please do a patch against mm-stable with
> >
> > Fixes: 20549ccf4da4 ("mm/hugetlb: free cross-zone bootmem gigantic pages after allocation")
> >
>