On Tue, Jun 10, 2025 at 08:58:42PM -0700, Eric Biggers wrote:

On Wed, Jun 11, 2025 at 11:46:47AM +0800, Herbert Xu wrote:

quoted

On Tue, Jun 10, 2025 at 08:39:57PM -0700, Eric Biggers wrote:

quoted

Do you have a concrete example (meaning, a specific driver) where this actually
matters?  Historically, export and import have always had to be paired for the
same transformation object, i.e. import was called only with the output of
export.  There is, and has never been, any test that tests otherwise.  This
seems like a brand new "requirement" that you've made up unnecessarily.

It's not just drivers that may be using fallbacks, the ahash API
code itself now relies on this to provide fallbacks for cases that
drivers can't handle, such as linear addresses.

I did add the testing for it, which revealed a few problems with
s390 so it was reverted for 6.16.  But I will be adding it back
after the s390 issues have been resolved.

Okay, so it sounds like in practice this is specific to ahash_do_req_chain()
which you recently added.  I'm not sure what it's meant to be doing.

You do know that most of the sha512 asynchronous hash drivers use custom state
formats and not your new one, right?  So your code in ahash_do_req_chain() is
broken for most asynchronous hash drivers anyway.

- Eric