[dpdk-dev] [PATCH v2 2/2] net/hinic: fix repeating log and length check

[Kevin Traynor]

gcc 10.0.1 reports:

../drivers/net/hinic/base/hinic_pmd_hwdev.c: In function ‘print_cable_info’:
../drivers/net/hinic/base/hinic_pmd_hwdev.c:1398:3:
warning:
‘snprintf’ argument 4 may overlap destination object ‘tmp_str’
[-Wrestrict]
 1398 |   snprintf(tmp_str + strlen(tmp_str), (sizeof(tmp_str) - 1),
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1399 |     "%s, Temperature: %u", tmp_str,
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1400 |     info->cable_temp);
      |     ~~~~~~~~~~~~~~~~~

The warning is that tmp_str is in both src and dest.

Anyway, the current code is incorrect and because of the +strlen
the existing string will be repeated twice and max length
does not limit to the end of the string.

Fix by removing tmp_str from the src of snprintf and adding the
correct max length.

Fixes: d9ce1917941c ("net/hinic/base: add hardware operation")
Cc: stable at dpdk.org

Signed-off-by: Kevin Traynor <ktraynor at redhat.com>

---
Cc: xuanziyang2 at huawei.com
Cc: cloud.wangxiaoyun at huawei.com
Cc: zhouguoyang at huawei.com
---
 drivers/net/hinic/base/hinic_pmd_hwdev.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hinic/base/hinic_pmd_hwdev.c b/drivers/net/hinic/base/hinic_pmd_hwdev.c
index b6c821a2a..fd0292f84 100644
--- a/drivers/net/hinic/base/hinic_pmd_hwdev.c
+++ b/drivers/net/hinic/base/hinic_pmd_hwdev.c
@@ -1396,7 +1396,7 @@ static void print_cable_info(struct hinic_link_info *info)
 		 info->cable_length, info->cable_max_speed);
 	if (info->port_type != LINK_PORT_COPPER)
-		snprintf(tmp_str + strlen(tmp_str), (sizeof(tmp_str) - 1),
-			 "%s, Temperature: %u", tmp_str,
-			 info->cable_temp);
+		snprintf(tmp_str + strlen(tmp_str),
+			 sizeof(tmp_str) - strlen(tmp_str),
+			 ", Temperature: %u", info->cable_temp);
 
 	PMD_DRV_LOG(INFO, "Cable information: %s", tmp_str);
-- 
2.21.1