crypto: chelsio - This fixes the kernel panic which occurs during a libkcapi test

The libkcapi test which causes kernel panic is
aead asynchronous vmsplice multiple test.

./bin/kcapi  -v -d 4 -x 10   -c "ccm(aes)"
-q 4edb58e8d5eb6bc711c43a6f3693daebde2e5524f1b55297abb29f003236e43d
-t a7877c99 -n 674742abd0f5ba -k 2861fd0253705d7875c95ba8a53171b4
-a fb7bc304a3909e66e2e0c5ef952712dd884ce3e7324171369f2c5db1adc48c7d

This patch avoids dma_mapping of a zero length sg which causes the panic,
by using sg_nents_for_len which maps only upto a specific length

Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/chelsio/chcr_algo.c b/drivers/crypto/chelsio/chcr_algo.c
index 699e3053895a824f7ef015165c66e794dac74e71..02b0ddb785a44372307f525ffec726c3c29a7a5b 100644 (file)
--- a/drivers/crypto/chelsio/chcr_algo.c
+++ b/drivers/crypto/chelsio/chcr_algo.c
@@ -2489,8 +2489,9 @@ int chcr_aead_dma_map(struct device *dev,
        else
                reqctx->b0_dma = 0;
        if (req->src == req->dst) {
-               error = dma_map_sg(dev, req->src, sg_nents(req->src),
-                                  DMA_BIDIRECTIONAL);
+               error = dma_map_sg(dev, req->src,
+                               sg_nents_for_len(req->src, dst_size),
+                                       DMA_BIDIRECTIONAL);
                if (!error)
                        goto err;
        } else {