On Mon, 2014-08-18 at 08:45 -0700, Alexander Duyck wrote: > On 08/18/2014 08:31 AM, Joe Perches wrote: > > On Mon, 2014-08-18 at 08:29 -0700, Alexander Duyck wrote: > >> Doing any kind of pointer math on a void pointer is generally unsafe as > >> it is an incomplete type. The only reason why it works in GCC is > >> because GCC has a nonstandard extension that makes it report as having a > >> size of 1. > > > > I know. It's used in quite a few places in kernel code > > so I believe it's now a base assumption for the kernel. > > Well that is something that should probably be fixed then. I don't > believe it is safe to be doing any kind of pointer math on a void pointer. > > We really shouldn't be using any GCC specific bits unless we absolutely > have to.
Good luck with that. Here's a little coccinelle script to find them: $ cat void_arithmetic.spatch @@ void *p; expression e; @@ * p + e $ There are at least 23 uses just in lib/ $ spatch -sp_file void_arithmetic.spatch lib | \ grep "^\-[^\-]" | wc -l 23 I'm fairly confident there are more than that, but using spatch with --recursive-includes is pretty slow on my machine. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
