Re: [GIT PULL] x86/build changes for v4.17

[Peter Zijlstra]

On Wed, Apr 04, 2018 at 10:21:05PM +0000, James Y Knight wrote:
> But allowing random pointer arithmetic, and pointer arithmetic wraparound,
> is still different than asserting that an object _field access_ can
> overflow. Clang does not believe that can happen -- it assumes that an
> object will still be contiguous. And that's why the llist stuff used to be
> broken, before it was corrected to do simply do math on a uintptr_t (which
> is a nice and simple and sane fix!).

That 'fix' wasn't anything simple, I recently ran into that
member_address_is_nonnull() trainwreck and had to think real hard wtf it
was about.