On Wed, Aug 21, 2019 at 05:32:44PM +0300, Ard Biesheuvel wrote:
> After starting a skcipher walk, the only way to ensure that all
> resources it has tied up are released is to complete it. In some
> cases, it will be useful to be able to abort a walk cleanly after
> it has started, so add this ability to the skcipher walk API.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> ---
> crypto/skcipher.c | 3 +++
> include/crypto/internal/skcipher.h | 5 +++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/crypto/skcipher.c b/crypto/skcipher.c
> index 5d836fc3df3e..973ab1c7dcca 100644
> --- a/crypto/skcipher.c
> +++ b/crypto/skcipher.c
> @@ -140,6 +140,9 @@ int skcipher_walk_done(struct skcipher_walk *walk, int err)
> goto already_advanced;
> }
>
> + if (unlikely(!n))
> + goto finish;
> +
> scatterwalk_advance(&walk->in, n);
> scatterwalk_advance(&walk->out, n);
> already_advanced:
> diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h
> index d68faa5759ad..bc488173531f 100644
> --- a/include/crypto/internal/skcipher.h
> +++ b/include/crypto/internal/skcipher.h
> @@ -148,6 +148,11 @@ int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
> struct aead_request *req, bool atomic);
> void skcipher_walk_complete(struct skcipher_walk *walk, int err);
>
> +static inline void skcipher_walk_abort(struct skcipher_walk *walk)
> +{
> + skcipher_walk_done(walk, walk->nbytes);
> +}
Couldn't you just abort it by supplying an error in place of
walk->bytes? IOW I'm fine with this helper but you don't need
to touch skcipher_walk_done as just giving it an negative err
value should do the trick.
Thanks,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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