[PATCH] [v2] hinic: avoid gcc -Wrestrict warning
From: Arnd Bergmann <arnd@kernel.org>
Date: 2021-03-24 13:08:22
Also in:
lkml
Subsystem:
huawei ethernet driver, networking drivers, the rest · Maintainers:
Cai Huoqing, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Arnd Bergmann <arnd@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 <linux@rasmusvillemoes.dk>
Signed-off-by: Arnd Bergmann <arnd@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