From: Tomas Mraz <tmraz@fedoraproject.org>
Date: Wed, 10 Aug 2016 13:21:32 +0000 (+0200)
Subject: Add a comment for the added cast with explanation.
X-Git-Tag: OpenSSL_1_1_0~190
X-Git-Url: https://git.openssl.org/?p=openssl.git;a=commitdiff_plain;h=e7e5d608fb6cef9929a2cf56d72fa7e236ca7573;hp=3f8d1216df7a4314fca77b6ee6fe9fc814fcd909

Add a comment for the added cast with explanation.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
---

diff --git a/engines/afalg/e_afalg.c b/engines/afalg/e_afalg.c
index 456ffda9aa..1766230ce8 100644
--- a/engines/afalg/e_afalg.c
+++ b/engines/afalg/e_afalg.c
@@ -230,6 +230,10 @@ int afalg_fin_cipher_aio(afalg_aio *aio, int sfd, unsigned char *buf,
     memset(cb, '\0', sizeof(*cb));
     cb->aio_fildes = sfd;
     cb->aio_lio_opcode = IOCB_CMD_PREAD;
+    /*
+     * The pointer has to be converted to unsigned value first to avoid
+     * sign extension on cast to 64 bit value
+     */
     cb->aio_buf = (uint64_t)(unsigned long)buf;
     cb->aio_offset = 0;
     cb->aio_data = 0;