Messages in this thread | | | Date | Tue, 17 Oct 2006 08:28:48 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [RFC] typechecking for get_unaligned/put_unaligned |
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On Tue, 17 Oct 2006, David Howells wrote:
> Al Viro <viro@ftp.linux.org.uk> wrote: > > > * sizeof(*ptr) should be one of 1, 2, 4, 8 > > Should we give an error if someone tries passing a 1-byte-sized memory location > to get/put_unaligned()? I suspect it might be best to reduce to a trivial > direct assignment in that case.
Note that in some cases, you have different architectures having different sizes, and it could potentially be the case that one architecture has a 1-byte thing, and another has a 2-byte thing.
It's unlikely to be an issue for single-byte cases, but it definitely happens for other equivalent things (ie "get_user()" often has 2 vs 4-byte accesses, and obviously the 4- vs 8-byte thing through 32/64-bit values depending on the size of the machine).
So at least in _theory_ it's quite possible that a single-byte access can make sense, simply because the size might depend on a config option.
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