crypto: api - Add scaffolding to change completion function signature

crypto: api - Add scaffolding to change completion function signature

BugLink: https://bugs.launchpad.net/bugs/2028580
[ Upstream commit c35e03eaece71101ff6cbf776b86403860ac8cc3 ]

The crypto completion function currently takes a pointer to a
struct crypto_async_request object.  However, in reality the API
does not allow the use of any part of the object apart from the
data field.  For example, ahash/shash will create a fake object
on the stack to pass along a different data field.

This leads to potential bugs where the user may try to dereference
or otherwise use the crypto_async_request object.

This patch adds some temporary scaffolding so that the completion
function can take a void * instead.  Once affected users have been
converted this can be removed.

The helper crypto_request_complete will remain even after the
conversion is complete.  It should be used instead of calling
the completion function directly.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stable-dep-of: 4140aafcff16 ("crypto: engine - fix crypto_queue backlog handling")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>