crypto: sun8i-ss - do not fallback if cryptlen is less than sg length

The sg length could be more than remaining data on it.
So check the length requirement against the minimum between those two
values.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
index 7f1940c6cc41fc6d4115a6a3e060c6f55f4344b6..5bb950182026f03deb572ab8eda48dd025f5d1cb 100644 (file)
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
@@ -28,6 +28,7 @@ static bool sun8i_ss_need_fallback(struct skcipher_request *areq)
        struct scatterlist *in_sg = areq->src;
        struct scatterlist *out_sg = areq->dst;
        struct scatterlist *sg;
+       unsigned int todo, len;
 
        if (areq->cryptlen == 0 || areq->cryptlen % 16) {
                algt->stat_fb_len++;
@@ -40,13 +41,11 @@ static bool sun8i_ss_need_fallback(struct skcipher_request *areq)
                return true;
        }
 
+       len = areq->cryptlen;
        sg = areq->src;
        while (sg) {
-               if ((sg->length % 16) != 0) {
-                       algt->stat_fb_sglen++;
-                       return true;
-               }
-               if ((sg_dma_len(sg) % 16) != 0) {
+               todo = min(len, sg->length);
+               if ((todo % 16) != 0) {
                        algt->stat_fb_sglen++;
                        return true;
                }
@@ -54,15 +53,14 @@ static bool sun8i_ss_need_fallback(struct skcipher_request *areq)
                        algt->stat_fb_align++;
                        return true;
                }
+               len -= todo;
                sg = sg_next(sg);
        }
+       len = areq->cryptlen;
        sg = areq->dst;
        while (sg) {
-               if ((sg->length % 16) != 0) {
-                       algt->stat_fb_sglen++;
-                       return true;
-               }
-               if ((sg_dma_len(sg) % 16) != 0) {
+               todo = min(len, sg->length);
+               if ((todo % 16) != 0) {
                        algt->stat_fb_sglen++;
                        return true;
                }
@@ -70,6 +68,7 @@ static bool sun8i_ss_need_fallback(struct skcipher_request *areq)
                        algt->stat_fb_align++;
                        return true;
                }
+               len -= todo;
                sg = sg_next(sg);
        }