crypto: talitos - fix hash on SEC1.

On SEC1, hash provides wrong result when performing hashing in several
steps with input data SG list has more than one element. This was
detected with CONFIG_CRYPTO_MANAGER_EXTRA_TESTS:

[   44.185947] alg: hash: md5-talitos test failed (wrong result) on test vector 6, cfg="random: may_sleep use_finup src_divs=[<reimport>25.88%@+8063, <flush>24.19%@+9588, 28.63%@+16333, <reimport>4.60%@+6756, 16.70%@+16281] dst_divs=[71.61%@alignmask+16361, 14.36%@+7756, 14.3%@+"
[   44.325122] alg: hash: sha1-talitos test failed (wrong result) on test vector 3, cfg="random: inplace use_final src_divs=[<flush,nosimd>16.56%@+16378, <reimport>52.0%@+16329, 21.42%@alignmask+16380, 10.2%@alignmask+16380] iv_offset=39"
[   44.493500] alg: hash: sha224-talitos test failed (wrong result) on test vector 4, cfg="random: use_final nosimd src_divs=[<reimport>52.27%@+7401, <reimport>17.34%@+16285, <flush>17.71%@+26, 12.68%@+10644] iv_offset=43"
[   44.673262] alg: hash: sha256-talitos test failed (wrong result) on test vector 4, cfg="random: may_sleep use_finup src_divs=[<reimport>60.6%@+12790, 17.86%@+1329, <reimport>12.64%@alignmask+16300, 8.29%@+15, 0.40%@+13506, <reimport>0.51%@+16322, <reimport>0.24%@+16339] dst_divs"

This is due to two issues:
- We have an overlap between the buffer used for copying the input
data (SEC1 doesn't do scatter/gather) and the chained descriptor.
- Data copy is wrong when the previous hash left less than one
blocksize of data to hash, implying a complement of the previous
block with a few bytes from the new request.

Fix it by:
- Moving the second descriptor after the buffer, as moving the buffer
after the descriptor would make it more complex for other cipher
operations (AEAD, ABLKCIPHER)
- Skip the bytes taken from the new request to complete the previous
one by moving the SG list forward.

Fixes: 37b5e889 ("crypto: talitos - chain in buffered data for ahash on SEC1")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/talitos.c

@@ -320,6 +320,21 @@ static int talitos_submit(struct device *dev, int ch, struct talitos_desc *desc,
 	return -EINPROGRESS;
 }
 
+static __be32 get_request_hdr(struct talitos_request *request, bool is_sec1)
+{
+	struct talitos_edesc *edesc;
+
+	if (!is_sec1)
+		return request->desc->hdr;
+
+	if (!request->desc->next_desc)
+		return request->desc->hdr1;
+
+	edesc = container_of(request->desc, struct talitos_edesc, desc);
+
+	return ((struct talitos_desc *)(edesc->buf + edesc->dma_len))->hdr1;
+}
+
 /*
  * process what was done, notify callback of error if not
  */
@@ -341,12 +356,7 @@ static void flush_channel(struct device *dev, int ch, int error, int reset_ch)
 
 		/* descriptors with their done bits set don't get the error */
 		rmb();
-		if (!is_sec1)
-			hdr = request->desc->hdr;
-		else if (request->desc->next_desc)
-			hdr = (request->desc + 1)->hdr1;
-		else
-			hdr = request->desc->hdr1;
+		hdr = get_request_hdr(request, is_sec1);
 
 		if ((hdr & DESC_HDR_DONE) == DESC_HDR_DONE)
 			status = 0;
@@ -476,8 +486,14 @@ static u32 current_desc_hdr(struct device *dev, int ch)
 		}
 	}
 
-	if (priv->chan[ch].fifo[iter].desc->next_desc == cur_desc)
-		return (priv->chan[ch].fifo[iter].desc + 1)->hdr;
+	if (priv->chan[ch].fifo[iter].desc->next_desc == cur_desc) {
+		struct talitos_edesc *edesc;
+
+		edesc = container_of(priv->chan[ch].fifo[iter].desc,
+				     struct talitos_edesc, desc);
+		return ((struct talitos_desc *)
+			(edesc->buf + edesc->dma_len))->hdr;
+	}
 
 	return priv->chan[ch].fifo[iter].desc->hdr;
 }
@@ -1402,15 +1418,11 @@ static struct talitos_edesc *talitos_edesc_alloc(struct device *dev,
 	edesc->dst_nents = dst_nents;
 	edesc->iv_dma = iv_dma;
 	edesc->dma_len = dma_len;
-	if (dma_len) {
-		void *addr = &edesc->link_tbl[0];
-
-		if (is_sec1 && !dst)
-			addr += sizeof(struct talitos_desc);
-		edesc->dma_link_tbl = dma_map_single(dev, addr,
+	if (dma_len)
+		edesc->dma_link_tbl = dma_map_single(dev, &edesc->link_tbl[0],
 						     edesc->dma_len,
 						     DMA_BIDIRECTIONAL);
-	}
+
 	return edesc;
 }
 
@@ -1722,13 +1734,15 @@ static void common_nonsnoop_hash_unmap(struct device *dev,
 	struct talitos_private *priv = dev_get_drvdata(dev);
 	bool is_sec1 = has_ftr_sec1(priv);
 	struct talitos_desc *desc = &edesc->desc;
-	struct talitos_desc *desc2 = desc + 1;
+	struct talitos_desc *desc2 = (struct talitos_desc *)
+				     (edesc->buf + edesc->dma_len);
 
 	unmap_single_talitos_ptr(dev, &edesc->desc.ptr[5], DMA_FROM_DEVICE);
 	if (desc->next_desc &&
 	    desc->ptr[5].ptr != desc2->ptr[5].ptr)
 		unmap_single_talitos_ptr(dev, &desc2->ptr[5], DMA_FROM_DEVICE);
 
+	if (req_ctx->psrc)
 		talitos_sg_unmap(dev, edesc, req_ctx->psrc, NULL, 0, 0);
 
 	/* When using hashctx-in, must unmap it. */
@@ -1796,7 +1810,6 @@ static void talitos_handle_buggy_hash(struct talitos_ctx *ctx,
 
 static int common_nonsnoop_hash(struct talitos_edesc *edesc,
 				struct ahash_request *areq, unsigned int length,
-				unsigned int offset,
 				void (*callback) (struct device *dev,
 						  struct talitos_desc *desc,
 						  void *context, int error))
@@ -1835,9 +1848,7 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,
 
 	sg_count = edesc->src_nents ?: 1;
 	if (is_sec1 && sg_count > 1)
-		sg_pcopy_to_buffer(req_ctx->psrc, sg_count,
-				   edesc->buf + sizeof(struct talitos_desc),
-				   length, req_ctx->nbuf);
+		sg_copy_to_buffer(req_ctx->psrc, sg_count, edesc->buf, length);
 	else if (length)
 		sg_count = dma_map_sg(dev, req_ctx->psrc, sg_count,
 				      DMA_TO_DEVICE);
@@ -1850,7 +1861,7 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,
 				       DMA_TO_DEVICE);
 	} else {
 		sg_count = talitos_sg_map(dev, req_ctx->psrc, length, edesc,
-					  &desc->ptr[3], sg_count, offset, 0);
+					  &desc->ptr[3], sg_count, 0, 0);
 		if (sg_count > 1)
 			sync_needed = true;
 	}
@@ -1874,7 +1885,8 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,
 		talitos_handle_buggy_hash(ctx, edesc, &desc->ptr[3]);
 
 	if (is_sec1 && req_ctx->nbuf && length) {
-		struct talitos_desc *desc2 = desc + 1;
+		struct talitos_desc *desc2 = (struct talitos_desc *)
+					     (edesc->buf + edesc->dma_len);
 		dma_addr_t next_desc;
 
 		memset(desc2, 0, sizeof(*desc2));
@@ -1895,7 +1907,7 @@ static int common_nonsnoop_hash(struct talitos_edesc *edesc,
 						      DMA_TO_DEVICE);
 		copy_talitos_ptr(&desc2->ptr[2], &desc->ptr[2], is_sec1);
 		sg_count = talitos_sg_map(dev, req_ctx->psrc, length, edesc,
-					  &desc2->ptr[3], sg_count, offset, 0);
+					  &desc2->ptr[3], sg_count, 0, 0);
 		if (sg_count > 1)
 			sync_needed = true;
 		copy_talitos_ptr(&desc2->ptr[5], &desc->ptr[5], is_sec1);
@@ -2006,7 +2018,6 @@ static int ahash_process_req(struct ahash_request *areq, unsigned int nbytes)
 	struct device *dev = ctx->dev;
 	struct talitos_private *priv = dev_get_drvdata(dev);
 	bool is_sec1 = has_ftr_sec1(priv);
-	int offset = 0;
 	u8 *ctx_buf = req_ctx->buf[req_ctx->buf_idx];
 
 	if (!req_ctx->last && (nbytes + req_ctx->nbuf <= blocksize)) {
@@ -2046,6 +2057,8 @@ static int ahash_process_req(struct ahash_request *areq, unsigned int nbytes)
 			sg_chain(req_ctx->bufsl, 2, areq->src);
 		req_ctx->psrc = req_ctx->bufsl;
 	} else if (is_sec1 && req_ctx->nbuf && req_ctx->nbuf < blocksize) {
+		int offset;
+
 		if (nbytes_to_hash > blocksize)
 			offset = blocksize - req_ctx->nbuf;
 		else
@@ -2058,7 +2071,8 @@ static int ahash_process_req(struct ahash_request *areq, unsigned int nbytes)
 		sg_copy_to_buffer(areq->src, nents,
 				  ctx_buf + req_ctx->nbuf, offset);
 		req_ctx->nbuf += offset;
-		req_ctx->psrc = areq->src;
+		req_ctx->psrc = scatterwalk_ffwd(req_ctx->bufsl, areq->src,
+						 offset);
 	} else
 		req_ctx->psrc = areq->src;
 
@@ -2098,8 +2112,7 @@ static int ahash_process_req(struct ahash_request *areq, unsigned int nbytes)
 	if (ctx->keylen && (req_ctx->first || req_ctx->last))
 		edesc->desc.hdr |= DESC_HDR_MODE0_MDEU_HMAC;
 
-	return common_nonsnoop_hash(edesc, areq, nbytes_to_hash, offset,
-				    ahash_done);
+	return common_nonsnoop_hash(edesc, areq, nbytes_to_hash, ahash_done);
 }
 
 static int ahash_update(struct ahash_request *areq)