Re: [PATCH 1/1] arm64: hibernate: add __force attribute to gfp_t casting

[Pavel Tatashin]

On Tue, Feb 2, 2021 at 3:42 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> On Mon, Feb 01, 2021 at 10:03:06AM -0500, Pavel Tatashin wrote:
> > Two new warnings are reported by sparse:
> >
> > "sparse warnings: (new ones prefixed by >>)"
> > >> arch/arm64/kernel/hibernate.c:181:39: sparse: sparse: cast to
> >    restricted gfp_t
> > >> arch/arm64/kernel/hibernate.c:202:44: sparse: sparse: cast from
> >    restricted gfp_t
> >
> > gfp_t has __bitwise type attribute and requires __force added to casting
> > in order to avoid these warnings.
> >
> > Fixes: 50f53fb72181 ("arm64: trans_pgd: make trans_pgd_map_page generic")
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
>
> What about just passing the gfp_t value by reference which would be much
> cleaner?


Hi Christoph,

Thank you for your suggestions. Passing by reference is OK. I am not
sure it would be much cleaner because for GFP_ATOMIC we would need to
declare another variable on stack before trans_info.

Pasha