On Fri, Jun 16, 2023 at 07:20:52PM +1200, Michael Schmitz wrote: > Am 16.06.2023 um 17:48 schrieb Christoph Hellwig: >> On Fri, Jun 16, 2023 at 07:53:11AM +1200, Michael Schmitz wrote: >>> Thanks - now there's two __s32 fields in that header - one checksum each >>> for RDB and PB. No one has so far seen the need for a 'signed big endian 32 >>> bit' type, and I'd rather avoid adding one to types.h. I'll leave those as >>> they are (with the tacit understanding that they are equally meant to be >>> big endian). >> >> We have those in a few other pleases and store them as __be32 as well. The >> (implicit) cast to s32 will make them signed again. > > Where's that cast to s32 hidden? I've only seen > > #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) > > which would make the checksums unsigned if __be32 was used. > > Whether the checksum code uses signed or unsigned math would require > inspection of the Amiga partitioning tool source which I don't have, so > I've kept __s32 to be safe. Well, the return value of be32_to_cpu is going to be a assigned to a, presumably signed, variable. With that you get an implicit cast.
