* Since the F_SEAL_FUTURE_WRITE seals allow for a MAP_SHARED
* read-only mapping, take care to not allow mprotect to revert
* protections.
* Since an F_SEAL_FUTURE_WRITE sealed memfd can be mapped as
* MAP_SHARED and read-only, take care to not allow mprotect to
* revert protections on such mappings. Do this only for shared
* mappings. For private mappings, don't need to mask VM_MAYWRITE
This adds an > 80 char line.