Re: [PATCH] mm: Add kvfree_sensitive() for freeing sensitive data objects

[Joe Perches]

On Mon, 2020-04-06 at 17:26 +0100, David Howells wrote:
> Joe Perches <joe@xxxxxxxxxxx> wrote:
> 
> > While I agree with Linus about the __ prefix,
> > the z is pretty common and symmetric to all
> > the <foo>zalloc uses.
> > 
> > And if _sensitive is actually used, it'd be
> > good to do a s/kzfree/kfree_sensitive/ one day
> > sooner than later.
> 
> How much overhead would it be to always use kvfree_sensitive() and never have
> a kfree_sensitive()?

I believe the is_vmalloc_addr not particularly expensive as it's
just 2 tests.

It might make sense to go back to static inline is_vmalloc_addr
instead of using EXPORT_SYMBOL