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

Matthew Wilcox
2020-04-06T17:24:57Z

On Mon, Apr 06, 2020 at 10:10:20AM -0700, Joe Perches wrote:
> On Mon, 2020-04-06 at 17:26 +0100, David Howells wrote:
> > Joe Perches <joe@perches.com> 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()?
>
> Another possibility:
>
> Add yet another alloc flag like __GFP_SENSITIVE
> and have kfree operate on that and not have a
> kfree_sensitive at all.

kfree() doesn't take GFP flags.