On Tue, Jun 16, 2020 at 12:54 PM Joe Perches [off-list ref] wrote:

On Mon, 2020-06-15 at 21:57 -0400, Waiman Long wrote:

quoted

 v4:
  - Break out the memzero_explicit() change as suggested by Dan Carpenter
    so that it can be backported to stable.
  - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for
    now as there can be a bit more discussion on what is best. It will be
    introduced as a separate patch later on after this one is merged.

To this larger audience and last week without reply:
https://lore.kernel.org/lkml/573b3fbd5927c643920e1364230c296b23e7584d.camel@perches.com/ (local)

Are there _any_ fastpath uses of kfree or vfree?

The networking stack has various places where there will be a quick
kmalloc followed by a kfree for an incoming or outgoing packet. One
place that comes to mind would be esp_alloc_tmp, which does a quick
allocation of some temporary kmalloc memory, processes some packet
things inside of that, and then frees it, sometimes in the same
function, and sometimes later in an async callback. I don't know how
"fastpath" you consider this, but usually packet processing is
something people want to do with minimal overhead, considering how
fast NICs are these days.