crypto: caam - Fix edesc/iv ordering mixup

The attempt to add DMA alignment padding by moving IV to the front
of edesc was completely broken as it didn't change the places where
edesc was freed.

It's also wrong as the IV may still share a cache-line with the
edesc.

Fix this by restoring the original layout and simply reserving
enough memmory so that the IV is on a DMA cache-line by itself.

Reported-by: Meenakshi Aggarwal <meenakshi.aggarwal@nxp.com>
Fixes: 199354d7fb6e ("crypto: caam - Remove GFP_DMA and add DMA alignment padding")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 19 insertions, 7 deletions

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index 4a9b998a8d26..12b1c8346243 100644
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -60,7 +60,11 @@
 #include <crypto/xts.h>
 #include <asm/unaligned.h>
 #include <linux/dma-mapping.h>
+#include <linux/device.h>
+#include <linux/err.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/string.h>
 
 /*
  * crypto alg
@@ -1000,6 +1004,13 @@ static void aead_crypt_done(struct device *jrdev, u32 *desc, u32 err,
 		crypto_finalize_aead_request(jrp->engine, req, ecode);
 }
 
+static inline u8 *skcipher_edesc_iv(struct skcipher_edesc *edesc)
+{
+
+	return PTR_ALIGN((u8 *)edesc->sec4_sg + edesc->sec4_sg_bytes,
+			 dma_get_cache_alignment());
+}
+
 static void skcipher_crypt_done(struct device *jrdev, u32 *desc, u32 err,
 				void *context)
 {
@@ -1027,8 +1038,7 @@ static void skcipher_crypt_done(struct device *jrdev, u32 *desc, u32 err,
 	 * This is used e.g. by the CTS mode.
 	 */
 	if (ivsize && !ecode) {
-		memcpy(req->iv, (u8 *)edesc->sec4_sg + edesc->sec4_sg_bytes,
-		       ivsize);
+		memcpy(req->iv, skcipher_edesc_iv(edesc), ivsize);
 
 		print_hex_dump_debug("dstiv  @" __stringify(__LINE__)": ",
 				     DUMP_PREFIX_ADDRESS, 16, 4, req->iv,
@@ -1683,18 +1693,19 @@ static struct skcipher_edesc *skcipher_edesc_alloc(struct skcipher_request *req,
 	/*
 	 * allocate space for base edesc and hw desc commands, link tables, IV
 	 */
-	aligned_size = ALIGN(ivsize, __alignof__(*edesc));
-	aligned_size += sizeof(*edesc) + desc_bytes + sec4_sg_bytes;
+	aligned_size = sizeof(*edesc) + desc_bytes + sec4_sg_bytes;
 	aligned_size = ALIGN(aligned_size, dma_get_cache_alignment());
-	iv = kzalloc(aligned_size, flags);
-	if (!iv) {
+	aligned_size += ~(ARCH_KMALLOC_MINALIGN - 1) &
+			(dma_get_cache_alignment() - 1);
+	aligned_size += ALIGN(ivsize, dma_get_cache_alignment());
+	edesc = kzalloc(aligned_size, flags);
+	if (!edesc) {
 		dev_err(jrdev, "could not allocate extended descriptor\n");
 		caam_unmap(jrdev, req->src, req->dst, src_nents, dst_nents, 0,
 			   0, 0, 0);
 		return ERR_PTR(-ENOMEM);
 	}
 
-	edesc = (void *)(iv + ALIGN(ivsize, __alignof__(*edesc)));
 	edesc->src_nents = src_nents;
 	edesc->dst_nents = dst_nents;
 	edesc->mapped_src_nents = mapped_src_nents;
@@ -1706,6 +1717,7 @@ static struct skcipher_edesc *skcipher_edesc_alloc(struct skcipher_request *req,
 
 	/* Make sure IV is located in a DMAable area */
 	if (ivsize) {
+		iv = skcipher_edesc_iv(edesc);
 		memcpy(iv, req->iv, ivsize);
 
 		iv_dma = dma_map_single(jrdev, iv, ivsize, DMA_BIDIRECTIONAL);