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From:   Corentin Labbe <clabbe@baylibre.com>
To:     davem@davemloft.net, herbert@gondor.apana.org.au,
        jernej.skrabec@gmail.com, mripard@kernel.org, wens@csie.org
Cc:     linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-sunxi@lists.linux.dev,
        linux-sunxi@googlegroups.com, Corentin Labbe <clabbe@baylibre.com>
Subject: [PATCH 3/8] crypto: sun8i-ss: handle zero sized sg
Date:   Wed, 26 Jan 2022 21:04:36 +0000
Message-Id: <20220126210441.3661782-4-clabbe@baylibre.com>
In-Reply-To: <20220126210441.3661782-1-clabbe@baylibre.com>
References: <20220126210441.3661782-1-clabbe@baylibre.com>
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sun8i-ss does not handle well the possible zero sized sg.

Fixes: d9b45418a917 ("crypto: sun8i-ss - support hash algorithms")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
---
 drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
index 3c073eb3db03..2557bb3fe7aa 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
@@ -379,13 +379,21 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
 	}
 
 	len = areq->nbytes;
-	for_each_sg(areq->src, sg, nr_sgs, i) {
+	sg = areq->src;
+	i = 0;
+	while (len > 0 && sg) {
+		if (sg_dma_len(sg) == 0) {
+			sg = sg_next(sg);
+			continue;
+		}
 		rctx->t_src[i].addr = sg_dma_address(sg);
 		todo = min(len, sg_dma_len(sg));
 		rctx->t_src[i].len = todo / 4;
 		len -= todo;
 		rctx->t_dst[i].addr = addr_res;
 		rctx->t_dst[i].len = digestsize / 4;
+		sg = sg_next(sg);
+		i++;
 	}
 	if (len > 0) {
 		dev_err(ss->dev, "remaining len %d\n", len);
-- 
2.34.1