There are a few places in the tree which compute the length of the
string representation of a MAC address as 3 * ETH_ALEN - 1. Define a
constant for this and use it where relevant. No functionality changes
are expected.
Signed-off-by: Uday Shankar <ushankar@purestorage.com>
---
drivers/net/netconsole.c | 2 +-
drivers/nvmem/brcm_nvram.c | 2 +-
drivers/nvmem/layouts/u-boot-env.c | 2 +-
include/linux/if_ether.h | 3 +++
lib/net_utils.c | 4 +---
net/mac80211/debugfs_sta.c | 5 +++--
6 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 86ab4a42769a49eebe5dd6f01dafafc6c86ec54f..78c143e65a3f337929f91f70b77e5bc88365eea7 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -675,7 +675,7 @@ static ssize_t remote_mac_store(struct config_item *item, const char *buf,
if (!mac_pton(buf, remote_mac))
goto out_unlock;
- if (buf[3 * ETH_ALEN - 1] && buf[3 * ETH_ALEN - 1] != '\n')
+ if (buf[MAC_ADDR_LEN] && buf[MAC_ADDR_LEN] != '\n')
goto out_unlock;
memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
diff --git a/drivers/nvmem/brcm_nvram.c b/drivers/nvmem/brcm_nvram.c
index b810df727b446b1762a1851750f743e0de6e8788..43608e45c58aa96a505d82733de1b24ef8d18a1b 100644
--- a/drivers/nvmem/brcm_nvram.c
+++ b/drivers/nvmem/brcm_nvram.c
@@ -100,7 +100,7 @@ static int brcm_nvram_read_post_process_macaddr(void *context, const char *id, i
{
u8 mac[ETH_ALEN];
- if (bytes != 3 * ETH_ALEN - 1)
+ if (bytes != MAC_ADDR_LEN)
return -EINVAL;
if (!mac_pton(buf, mac))
diff --git a/drivers/nvmem/layouts/u-boot-env.c b/drivers/nvmem/layouts/u-boot-env.c
index 731e6f4f12b2bf28e4547d128954a095545ad461..4a6c0d0e6dc90a138bfbb402d401d41f59c021f8 100644
--- a/drivers/nvmem/layouts/u-boot-env.c
+++ b/drivers/nvmem/layouts/u-boot-env.c
@@ -37,7 +37,7 @@ static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, i
{
u8 mac[ETH_ALEN];
- if (bytes != 3 * ETH_ALEN - 1)
+ if (bytes != MAC_ADDR_LEN)
return -EINVAL;
if (!mac_pton(buf, mac))
diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index 8a9792a6427ad9cf58b50c79cbfe185615800dcb..afb2fdc0af653626034ae5e19309c8427272a828 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -19,6 +19,9 @@
#include <linux/skbuff.h>
#include <uapi/linux/if_ether.h>
+/* XX:XX:XX:XX:XX:XX */
+#define MAC_ADDR_LEN (3 * ETH_ALEN - 1)
+
static inline struct ethhdr *eth_hdr(const struct sk_buff *skb)
{
return (struct ethhdr *)skb_mac_header(skb);
diff --git a/lib/net_utils.c b/lib/net_utils.c
index 42bb0473fb22f977409f7a6792bb1340f4e911c3..0aedd4854d85ba89dbf0e7451b3f6b197cfac1de 100644
--- a/lib/net_utils.c
+++ b/lib/net_utils.c
@@ -7,11 +7,9 @@
bool mac_pton(const char *s, u8 *mac)
{
- size_t maxlen = 3 * ETH_ALEN - 1;
int i;
- /* XX:XX:XX:XX:XX:XX */
- if (strnlen(s, maxlen) < maxlen)
+ if (strnlen(s, MAC_ADDR_LEN) < MAC_ADDR_LEN)
return false;
/* Don't dirty result unless string is valid MAC. */
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index a67a9d3160086ac492d77092a0c8a74d2384b28c..29f45382367e4f6cceb0e0b5f04db1c408da712e 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -457,11 +457,12 @@ static ssize_t link_sta_addr_read(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct link_sta_info *link_sta = file->private_data;
- u8 mac[3 * ETH_ALEN + 1];
+ u8 mac[MAC_ADDR_LEN + 2];
snprintf(mac, sizeof(mac), "%pM\n", link_sta->pub->addr);
- return simple_read_from_buffer(userbuf, count, ppos, mac, 3 * ETH_ALEN);
+ return simple_read_from_buffer(userbuf, count, ppos, mac,
+ MAC_ADDR_LEN + 1);
}
LINK_STA_OPS(addr);
--
2.34.1Hi Uday,
kernel test robot noticed the following build warnings:
[auto build test WARNING on c2933b2befe25309f4c5cfbea0ca80909735fd76]
url: https://github.com/intel-lab-lkp/linux/commits/Uday-Shankar/net-treewide-define-and-use-MAC_ADDR_LEN/20250205-054620
base: c2933b2befe25309f4c5cfbea0ca80909735fd76
patch link: https://lore.kernel.org/r/20250204-netconsole-v2-1-5ef5eb5f6056%40purestorage.com
patch subject: [PATCH v2 1/2] net, treewide: define and use MAC_ADDR_LEN
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20250206/202502061751.GNyqzMGp-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250206/202502061751.GNyqzMGp-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202502061751.GNyqzMGp-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from drivers/scsi/qla4xxx/ql4_os.c:8:
In file included from include/linux/blkdev.h:9:
In file included from include/linux/blk_types.h:10:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:8:
In file included from include/linux/cacheflush.h:5:
In file included from arch/x86/include/asm/cacheflush.h:5:
In file included from include/linux/mm.h:2224:
include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
505 | item];
| ~~~~
include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
512 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
525 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/scsi/qla4xxx/ql4_os.c:15:
>> drivers/scsi/qla4xxx/ql4_def.h:148:9: warning: 'MAC_ADDR_LEN' macro redefined [-Wmacro-redefined]
148 | #define MAC_ADDR_LEN 6 /* in bytes */
| ^
include/linux/if_ether.h:23:9: note: previous definition is here
23 | #define MAC_ADDR_LEN (3 * ETH_ALEN - 1)
| ^
4 warnings generated.
--
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8188ee/dm.c:4:
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8188ee/../wifi.h:11:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:17:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:8:
In file included from include/linux/cacheflush.h:5:
In file included from arch/x86/include/asm/cacheflush.h:5:
In file included from include/linux/mm.h:2224:
include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
505 | item];
| ~~~~
include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
512 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
525 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8188ee/dm.c:8:
>> drivers/net/wireless/realtek/rtlwifi/rtl8188ee/reg.h:1230:9: warning: 'MAC_ADDR_LEN' macro redefined [-Wmacro-redefined]
1230 | #define MAC_ADDR_LEN 6
| ^
include/linux/if_ether.h:23:9: note: previous definition is here
23 | #define MAC_ADDR_LEN (3 * ETH_ALEN - 1)
| ^
4 warnings generated.
--
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8192ee/dm.c:4:
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8192ee/../wifi.h:11:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:17:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:8:
In file included from include/linux/cacheflush.h:5:
In file included from arch/x86/include/asm/cacheflush.h:5:
In file included from include/linux/mm.h:2224:
include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
505 | item];
| ~~~~
include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
512 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
525 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8192ee/dm.c:8:
>> drivers/net/wireless/realtek/rtlwifi/rtl8192ee/reg.h:1192:9: warning: 'MAC_ADDR_LEN' macro redefined [-Wmacro-redefined]
1192 | #define MAC_ADDR_LEN 6
| ^
include/linux/if_ether.h:23:9: note: previous definition is here
23 | #define MAC_ADDR_LEN (3 * ETH_ALEN - 1)
| ^
4 warnings generated.
--
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8723ae/dm.c:4:
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8723ae/../wifi.h:11:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:17:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:8:
In file included from include/linux/cacheflush.h:5:
In file included from arch/x86/include/asm/cacheflush.h:5:
In file included from include/linux/mm.h:2224:
include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
505 | item];
| ~~~~
include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
512 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
525 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8723ae/dm.c:8:
>> drivers/net/wireless/realtek/rtlwifi/rtl8723ae/reg.h:1194:9: warning: 'MAC_ADDR_LEN' macro redefined [-Wmacro-redefined]
1194 | #define MAC_ADDR_LEN 6
| ^
include/linux/if_ether.h:23:9: note: previous definition is here
23 | #define MAC_ADDR_LEN (3 * ETH_ALEN - 1)
| ^
4 warnings generated.
--
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8723be/dm.c:4:
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8723be/../wifi.h:11:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:17:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:8:
In file included from include/linux/cacheflush.h:5:
In file included from arch/x86/include/asm/cacheflush.h:5:
In file included from include/linux/mm.h:2224:
include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
505 | item];
| ~~~~
include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
512 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
525 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8723be/dm.c:8:
>> drivers/net/wireless/realtek/rtlwifi/rtl8723be/reg.h:1245:9: warning: 'MAC_ADDR_LEN' macro redefined [-Wmacro-redefined]
1245 | #define MAC_ADDR_LEN 6
| ^
include/linux/if_ether.h:23:9: note: previous definition is here
23 | #define MAC_ADDR_LEN (3 * ETH_ALEN - 1)
| ^
4 warnings generated.
--
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8821ae/dm.c:4:
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8821ae/../wifi.h:11:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:17:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:8:
In file included from include/linux/cacheflush.h:5:
In file included from arch/x86/include/asm/cacheflush.h:5:
In file included from include/linux/mm.h:2224:
include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
505 | item];
| ~~~~
include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
512 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
525 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/wireless/realtek/rtlwifi/rtl8821ae/dm.c:8:
>> drivers/net/wireless/realtek/rtlwifi/rtl8821ae/reg.h:1274:9: warning: 'MAC_ADDR_LEN' macro redefined [-Wmacro-redefined]
1274 | #define MAC_ADDR_LEN 6
| ^
include/linux/if_ether.h:23:9: note: previous definition is here
23 | #define MAC_ADDR_LEN (3 * ETH_ALEN - 1)
| ^
4 warnings generated.
vim +/MAC_ADDR_LEN +148 drivers/scsi/qla4xxx/ql4_def.h
afaf5a2d341d33 David Somayajulu 2006-09-19 144
afaf5a2d341d33 David Somayajulu 2006-09-19 145 /*
afaf5a2d341d33 David Somayajulu 2006-09-19 146 * Misc
afaf5a2d341d33 David Somayajulu 2006-09-19 147 */
afaf5a2d341d33 David Somayajulu 2006-09-19 @148 #define MAC_ADDR_LEN 6 /* in bytes */
afaf5a2d341d33 David Somayajulu 2006-09-19 149 #define IP_ADDR_LEN 4 /* in bytes */
2a49a78ed3c8d7 Vikas Chaudhary 2010-04-28 150 #define IPv6_ADDR_LEN 16 /* IPv6 address size */
afaf5a2d341d33 David Somayajulu 2006-09-19 151 #define DRIVER_NAME "qla4xxx"
afaf5a2d341d33 David Somayajulu 2006-09-19 152
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On Tue, 2025-02-04 at 14:41 -0700, Uday Shankar wrote: > There are a few places in the tree which compute the length of the > string representation of a MAC address as 3 * ETH_ALEN - 1. Define a > constant for this and use it where relevant. No functionality changes > are expected. True ... but is "MAC_ADDR_LEN" really an appropriate name for that? Just plain reading the subject, my first thought was why you weren't going to use ETH_ALEN. Would seem nicer to me, at least, to have something indicating a *string* in there, e.g. MAC_ADDR_STR_LEN or so. johannes
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