From: Arnd Bergmann <a...@arndb.de>

With extra warnings enabled, gcc complains that snprintf should not
take the same buffer as source and destination:

drivers/net/ethernet/huawei/hinic/hinic_ethtool.c: In function 
'hinic_set_settings_to_hw':
drivers/net/ethernet/huawei/hinic/hinic_ethtool.c:480:9: error: 'snprintf' 
argument 4 overlaps destination object 'set_link_str' [-Werror=restrict]
  480 |   err = snprintf(set_link_str, SET_LINK_STR_MAX_LEN,
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  481 |           "%sspeed %d ", set_link_str, speed);
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/huawei/hinic/hinic_ethtool.c:464:7: note: destination 
object referenced by 'restrict'-qualified argument 1 was declared here
  464 |  char set_link_str[SET_LINK_STR_MAX_LEN] = {0};

Rewrite this to avoid the nested sprintf and instead use separate
buffers, which is simpler.

Cc: Rasmus Villemoes <li...@rasmusvillemoes.dk>
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
v2: rework according to feedback from Rasmus. This one could
    easily avoid most of the pitfalls
---
 .../net/ethernet/huawei/hinic/hinic_ethtool.c | 25 ++++++++-----------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/huawei/hinic/hinic_ethtool.c 
b/drivers/net/ethernet/huawei/hinic/hinic_ethtool.c
index c340d9acba80..d7e20dab6e48 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_ethtool.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_ethtool.c
@@ -34,7 +34,7 @@
 #include "hinic_rx.h"
 #include "hinic_dev.h"
 
-#define SET_LINK_STR_MAX_LEN   128
+#define SET_LINK_STR_MAX_LEN   16
 
 #define GET_SUPPORTED_MODE     0
 #define GET_ADVERTISED_MODE    1
@@ -462,24 +462,19 @@ static int hinic_set_settings_to_hw(struct hinic_dev 
*nic_dev,
 {
        struct hinic_link_ksettings_info settings = {0};
        char set_link_str[SET_LINK_STR_MAX_LEN] = {0};
+       const char *autoneg_str;
        struct net_device *netdev = nic_dev->netdev;
        enum nic_speed_level speed_level = 0;
        int err;
 
-       err = snprintf(set_link_str, SET_LINK_STR_MAX_LEN, "%s",
-                      (set_settings & HILINK_LINK_SET_AUTONEG) ?
-                      (autoneg ? "autong enable " : "autong disable ") : "");
-       if (err < 0 || err >= SET_LINK_STR_MAX_LEN) {
-               netif_err(nic_dev, drv, netdev, "Failed to snprintf link state, 
function return(%d) and dest_len(%d)\n",
-                         err, SET_LINK_STR_MAX_LEN);
-               return -EFAULT;
-       }
+       autoneg_str = (set_settings & HILINK_LINK_SET_AUTONEG) ?
+                     (autoneg ? "autong enable " : "autong disable ") : "";
 
        if (set_settings & HILINK_LINK_SET_SPEED) {
                speed_level = hinic_ethtool_to_hw_speed_level(speed);
                err = snprintf(set_link_str, SET_LINK_STR_MAX_LEN,
-                              "%sspeed %d ", set_link_str, speed);
-               if (err <= 0 || err >= SET_LINK_STR_MAX_LEN) {
+                              "speed %d ", speed);
+               if (err >= SET_LINK_STR_MAX_LEN) {
                        netif_err(nic_dev, drv, netdev, "Failed to snprintf 
link speed, function return(%d) and dest_len(%d)\n",
                                  err, SET_LINK_STR_MAX_LEN);
                        return -EFAULT;
@@ -494,11 +489,11 @@ static int hinic_set_settings_to_hw(struct hinic_dev 
*nic_dev,
        err = hinic_set_link_settings(nic_dev->hwdev, &settings);
        if (err != HINIC_MGMT_CMD_UNSUPPORTED) {
                if (err)
-                       netif_err(nic_dev, drv, netdev, "Set %s failed\n",
-                                 set_link_str);
+                       netif_err(nic_dev, drv, netdev, "Set %s%sfailed\n",
+                                 autoneg_str, set_link_str);
                else
-                       netif_info(nic_dev, drv, netdev, "Set %s 
successfully\n",
-                                  set_link_str);
+                       netif_info(nic_dev, drv, netdev, "Set 
%s%ssuccessfully\n",
+                                  autoneg_str, set_link_str);
 
                return err;
        }
-- 
2.29.2

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