[PATCH 4.19 414/639] crypto: inside-secure - fix queued len computation

[Greg Kroah-Hartman]

From: Antoine Tenart <antoine.tenart@xxxxxxxxxxx>

[ Upstream commit ccd65a206a5025cf953a2e4f37e894921b131a5c ]

This patch fixes the queued len computation, which could theoretically
be wrong if req->len[1] - req->processed[1] > 1. Be future-proof here,
and fix it.

Fixes: b460edb6230a ("crypto: inside-secure - sha512 support")
Signed-off-by: Antoine Tenart <antoine.tenart@xxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/crypto/inside-secure/safexcel_hash.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/inside-secure/safexcel_hash.c b/drivers/crypto/inside-secure/safexcel_hash.c
index 9a02f64a45b96..f3b02c00b7846 100644
--- a/drivers/crypto/inside-secure/safexcel_hash.c
+++ b/drivers/crypto/inside-secure/safexcel_hash.c
@@ -50,10 +50,12 @@ struct safexcel_ahash_req {
 
 static inline u64 safexcel_queued_len(struct safexcel_ahash_req *req)
 {
-	if (req->len[1] > req->processed[1])
-		return 0xffffffff - (req->len[0] - req->processed[0]);
+	u64 len, processed;
 
-	return req->len[0] - req->processed[0];
+	len = (0xffffffff * req->len[1]) + req->len[0];
+	processed = (0xffffffff * req->processed[1]) + req->processed[0];
+
+	return len - processed;
 }
 
 static void safexcel_hash_token(struct safexcel_command_desc *cdesc,
-- 
2.20.1