crypto: hisilicon - Fix issue with wrong number of sg elements after dma map

We fill the hardware scatter gather list assuming it will need the same
number of elements at the original scatterlist. If an IOMMU is involved,
then it may well need fewer. The return value of dma_map_sg tells us how
many.

Probably never caused visible problems as the hardware won't get to
the elements that are incorrect before it finds enough space.

Fixes: dfed0098ab91 (crypto: hisilicon - add hardware SGL support)
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/hisilicon/sgl.c b/drivers/crypto/hisilicon/sgl.c
index 012023c347b1c7adf7fea767c0853a0e0f1cbebe..1e153a0d7c109ea9a7e3f820d62ed65c5f1a328b 100644 (file)
--- a/drivers/crypto/hisilicon/sgl.c
+++ b/drivers/crypto/hisilicon/sgl.c
@@ -202,18 +202,21 @@ hisi_acc_sg_buf_map_to_hw_sgl(struct device *dev,
        dma_addr_t curr_sgl_dma = 0;
        struct acc_hw_sge *curr_hw_sge;
        struct scatterlist *sg;
-       int i, ret, sg_n;
+       int i, sg_n, sg_n_mapped;
 
        if (!dev || !sgl || !pool || !hw_sgl_dma)
                return ERR_PTR(-EINVAL);
 
        sg_n = sg_nents(sgl);
-       if (sg_n > pool->sge_nr)
+
+       sg_n_mapped = dma_map_sg(dev, sgl, sg_n, DMA_BIDIRECTIONAL);
+       if (!sg_n_mapped)
                return ERR_PTR(-EINVAL);
 
-       ret = dma_map_sg(dev, sgl, sg_n, DMA_BIDIRECTIONAL);
-       if (!ret)
+       if (sg_n_mapped > pool->sge_nr) {
+               dma_unmap_sg(dev, sgl, sg_n, DMA_BIDIRECTIONAL);
                return ERR_PTR(-EINVAL);
+       }
 
        curr_hw_sgl = acc_get_sgl(pool, index, &curr_sgl_dma);
        if (IS_ERR(curr_hw_sgl)) {
@@ -224,7 +227,7 @@ hisi_acc_sg_buf_map_to_hw_sgl(struct device *dev,
        curr_hw_sgl->entry_length_in_sgl = cpu_to_le16(pool->sge_nr);
        curr_hw_sge = curr_hw_sgl->sge_entries;
 
-       for_each_sg(sgl, sg, sg_n, i) {
+       for_each_sg(sgl, sg, sg_n_mapped, i) {
                sg_map_to_hw_sg(sg, curr_hw_sge);
                inc_hw_sgl_sge(curr_hw_sgl);
                curr_hw_sge++;