Merge tag 'usercopy-v4.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardened usercopy fixes from Kees Cook:
 - avoid signed math problems on unexpected compilers
 - avoid false positives at very end of kernel text range checks

* tag 'usercopy-v4.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  usercopy: fix overlap check for kernel text
  usercopy: avoid potentially undefined behavior in pointer math