Re: [PATCH 2/2] vmalloc: reject vmap with VM_FLUSH_RESET_PERMS

[Christoph Hellwig]

On Fri, Dec 23, 2022 at 10:24:25AM +0000, Lorenzo Stoakes wrote:
> Might it be worth adding a specific vmap mask that explicitly indicates what
> flags are permissible on vmap()? Then this could become e.g.:-
> 
> 	if (WARN_ON_ONCE(flags & ~VM_VMAP_PERMITTED_MASK))
> 		return NULL;
> 
> And would be self-documenting as to why we are disallowing flags (i.e. they are
> not part of the permitted vmap mask).

That's probably a good idea.  It might need some time to audit
for use of all the flags, though.