From: Hugh Dickins <hugh@veritas.com>

Stas Sergeev <stsp@aknet.ru> wrote:

   mprotect() fails to merge VMAs because one VMA can end up with
   VM_ACCOUNT flag set, and another without that flag.  That makes several
   apps of mine to malfuncate.


Great find!  Someone has got their test the wrong way round.  Since that
VM_MAYACCT macro is being used in one place only, and just hiding what it's
actually about, fold it into its callsite.