Re: [PATCH 1/2] memfd: Fix COW issue on MAP_PRIVATE and F_SEAL_FUTURE_WRITE mappings

From: Joel Fernandes
Date: Fri Nov 08 2019 - 10:35:47 EST


On Thu, Nov 07, 2019 at 10:33:08PM -0800, Christoph Hellwig wrote:
> > - * 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.

Oh, true. Sorry. Andrew I hate to ask you but since you took the patch
already, could you just the comment for the character limit in the one
you applied?

thanks,

- Joel