From: Corentin Labbe Subject: Re: [PATCH 1/2] sun4i_ss_prng: fix return value of sun4i_ss_prng_generate Date: Wed, 7 Feb 2018 14:12:14 +0100 Message-ID: <20180207131214.GC19249@Red> References: <20180206212022.1309-1-artem.savkov@gmail.com> <20180206212022.1309-2-artem.savkov@gmail.com> <20180207095659.GA19249@Red> <20180207105201.pnn2s57wdk5zuda2@shodan.usersys.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Artem Savkov , herbert@gondor.apana.org.au, linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org To: Artem Savkov Return-path: Content-Disposition: inline In-Reply-To: <20180207105201.pnn2s57wdk5zuda2@shodan.usersys.redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Wed, Feb 07, 2018 at 11:52:01AM +0100, Artem Savkov wrote: > On Wed, Feb 07, 2018 at 10:56:59AM +0100, Corentin Labbe wrote: > > On Tue, Feb 06, 2018 at 10:20:21PM +0100, Artem Savkov wrote: > > > According to crypto/rng.h generate function should return 0 on success > > > and < 0 on error. > > > > > > Fixes: b8ae5c7387ad ("crypto: sun4i-ss - support the Security System PRNG") > > > Signed-off-by: Artem Savkov > > > --- > > > drivers/crypto/sunxi-ss/sun4i-ss-prng.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-prng.c b/drivers/crypto/sunxi-ss/sun4i-ss-prng.c > > > index 0d01d1624252..5754e0b92fb0 100644 > > > --- a/drivers/crypto/sunxi-ss/sun4i-ss-prng.c > > > +++ b/drivers/crypto/sunxi-ss/sun4i-ss-prng.c > > > @@ -52,5 +52,5 @@ int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src, > > > > > > writel(0, ss->base + SS_CTL); > > > spin_unlock(&ss->slock); > > > - return dlen; > > > + return 0; > > > } > > > -- > > > 2.15.1 > > > > > > > According to Documentation/crypto/api-samples.rst ("Code Example For Random Number Generator Usage") > > you must return the length of data generated. > > I don't think that example is the same as rng_alg.generate, it has a > different protottype. crypto_rng_get_bytes() use crypto_rng_generate() which work on crypto_rng > > > So crypto_rng_generate/crypto_rng_get_bytes documentation in crypto/rng.h must be fixed. > > It's not just documentation, every other rng driver returns it this way > and it gets aead_init_geniv() (and subsequently crypto_create_tfm()) > really confused because they expect the return value to be 0 or < 0. > Perhaps the example is wrong because "copied from/inspirated by" hwrng API which have this behavior. After checking, other crypto_rng driver, you are probably right, so you can add: Acked-by: Corentin Labbe Thanks Regards