[PATCH] net: sfc: avoid format string warning
From: Arnd Bergmann
Date: Fri Mar 20 2026 - 11:22:56 EST
From: Arnd Bergmann <arnd@xxxxxxxx>
Three sfc drivers contain the same *_fill_test() function that takes
a format string argument that gets passed down to snprintf(), producing
a warning with clang-22:
drivers/net/ethernet/sfc/falcon/ethtool.c:227:60: error: diagnostic behavior may be improved by adding
the 'format(printf, 7, 8)' attribute to the declaration of 'ef4_fill_test' [-Werror,-Wmissing-format-attribute]
210 | snprintf(test_str, sizeof(test_str), test_format, test_id);
| ^
drivers/net/ethernet/sfc/falcon/ethtool.c:210:13: note: 'ef4_fill_test' declared here
Rework these to take a varargs based test_format that allows better
type checking and avoids this warning.
Fixes: 3273c2e8c66a ("[netdrvr] sfc: sfc: Add self-test support")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/ethernet/sfc/ethtool_common.c | 28 ++++++++++--------
drivers/net/ethernet/sfc/falcon/ethtool.c | 27 ++++++++++-------
.../net/ethernet/sfc/siena/ethtool_common.c | 29 +++++++++++--------
3 files changed, 49 insertions(+), 35 deletions(-)
diff --git a/drivers/net/ethernet/sfc/ethtool_common.c b/drivers/net/ethernet/sfc/ethtool_common.c
index 54f8e4626568..162be23edbe5 100644
--- a/drivers/net/ethernet/sfc/ethtool_common.c
+++ b/drivers/net/ethernet/sfc/ethtool_common.c
@@ -254,9 +254,10 @@ int efx_ethtool_set_pauseparam(struct net_device *net_dev,
*
* Fill in an individual self-test entry.
*/
-static void efx_fill_test(unsigned int test_index, u8 *strings, u64 *data,
- int *test, const char *unit_format, int unit_id,
- const char *test_format, const char *test_id)
+static void __printf(7, 8)
+efx_fill_test(unsigned int test_index, u8 *strings, u64 *data,
+ int *test, const char *unit_format, int unit_id,
+ const char *test_format, ...)
{
char unit_str[ETH_GSTRING_LEN], test_str[ETH_GSTRING_LEN];
@@ -266,12 +267,15 @@ static void efx_fill_test(unsigned int test_index, u8 *strings, u64 *data,
/* Fill string, if applicable */
if (strings) {
+ va_list args;
if (strchr(unit_format, '%'))
snprintf(unit_str, sizeof(unit_str),
unit_format, unit_id);
else
strcpy(unit_str, unit_format);
- snprintf(test_str, sizeof(test_str), test_format, test_id);
+ va_start(args, test_format);
+ vsnprintf(test_str, sizeof(test_str), test_format, args);
+ va_end(args);
snprintf(strings + test_index * ETH_GSTRING_LEN,
ETH_GSTRING_LEN,
"%-6s %-24s", unit_str, test_str);
@@ -349,28 +353,28 @@ int efx_ethtool_fill_self_tests(struct efx_nic *efx,
enum efx_loopback_mode mode;
efx_fill_test(n++, strings, data, &tests->phy_alive,
- "phy", 0, "alive", NULL);
+ "phy", 0, "alive");
efx_fill_test(n++, strings, data, &tests->nvram,
- "core", 0, "nvram", NULL);
+ "core", 0, "nvram");
efx_fill_test(n++, strings, data, &tests->interrupt,
- "core", 0, "interrupt", NULL);
+ "core", 0, "interrupt");
/* Event queues */
efx_for_each_channel(channel, efx) {
efx_fill_test(n++, strings, data,
&tests->eventq_dma[channel->channel],
EFX_CHANNEL_NAME(channel),
- "eventq.dma", NULL);
+ "eventq.dma");
efx_fill_test(n++, strings, data,
&tests->eventq_int[channel->channel],
EFX_CHANNEL_NAME(channel),
- "eventq.int", NULL);
+ "eventq.int");
}
efx_fill_test(n++, strings, data, &tests->memory,
- "core", 0, "memory", NULL);
+ "core", 0, "memory");
efx_fill_test(n++, strings, data, &tests->registers,
- "core", 0, "registers", NULL);
+ "core", 0, "registers");
for (i = 0; true; ++i) {
const char *name;
@@ -380,7 +384,7 @@ int efx_ethtool_fill_self_tests(struct efx_nic *efx,
if (name == NULL)
break;
- efx_fill_test(n++, strings, data, &tests->phy_ext[i], "phy", 0, name, NULL);
+ efx_fill_test(n++, strings, data, &tests->phy_ext[i], "phy", 0, "%s", name);
}
/* Loopback tests */
diff --git a/drivers/net/ethernet/sfc/falcon/ethtool.c b/drivers/net/ethernet/sfc/falcon/ethtool.c
index 807c587eba3b..1ae8acb8fdc8 100644
--- a/drivers/net/ethernet/sfc/falcon/ethtool.c
+++ b/drivers/net/ethernet/sfc/falcon/ethtool.c
@@ -207,9 +207,10 @@ static void ef4_ethtool_set_msglevel(struct net_device *net_dev, u32 msg_enable)
*
* Fill in an individual self-test entry.
*/
-static void ef4_fill_test(unsigned int test_index, u8 *strings, u64 *data,
+static void __printf(7, 8)
+ ef4_fill_test(unsigned int test_index, u8 *strings, u64 *data,
int *test, const char *unit_format, int unit_id,
- const char *test_format, const char *test_id)
+ const char *test_format, ...)
{
char unit_str[ETH_GSTRING_LEN], test_str[ETH_GSTRING_LEN];
@@ -219,12 +220,16 @@ static void ef4_fill_test(unsigned int test_index, u8 *strings, u64 *data,
/* Fill string, if applicable */
if (strings) {
+ va_list arg;
+
if (strchr(unit_format, '%'))
snprintf(unit_str, sizeof(unit_str),
unit_format, unit_id);
else
strcpy(unit_str, unit_format);
- snprintf(test_str, sizeof(test_str), test_format, test_id);
+ va_start(arg, test_format);
+ vsnprintf(test_str, sizeof(test_str), test_format, arg);
+ va_end(arg);
snprintf(strings + test_index * ETH_GSTRING_LEN,
ETH_GSTRING_LEN,
"%-6s %-24s", unit_str, test_str);
@@ -303,28 +308,28 @@ static int ef4_ethtool_fill_self_tests(struct ef4_nic *efx,
enum ef4_loopback_mode mode;
ef4_fill_test(n++, strings, data, &tests->phy_alive,
- "phy", 0, "alive", NULL);
+ "phy", 0, "alive");
ef4_fill_test(n++, strings, data, &tests->nvram,
- "core", 0, "nvram", NULL);
+ "core", 0, "nvram");
ef4_fill_test(n++, strings, data, &tests->interrupt,
- "core", 0, "interrupt", NULL);
+ "core", 0, "interrupt");
/* Event queues */
ef4_for_each_channel(channel, efx) {
ef4_fill_test(n++, strings, data,
&tests->eventq_dma[channel->channel],
EF4_CHANNEL_NAME(channel),
- "eventq.dma", NULL);
+ "eventq.dma");
ef4_fill_test(n++, strings, data,
&tests->eventq_int[channel->channel],
EF4_CHANNEL_NAME(channel),
- "eventq.int", NULL);
+ "eventq.int");
}
ef4_fill_test(n++, strings, data, &tests->memory,
- "core", 0, "memory", NULL);
+ "core", 0, "memory");
ef4_fill_test(n++, strings, data, &tests->registers,
- "core", 0, "registers", NULL);
+ "core", 0, "registers");
if (efx->phy_op->run_tests != NULL) {
EF4_BUG_ON_PARANOID(efx->phy_op->test_name == NULL);
@@ -338,7 +343,7 @@ static int ef4_ethtool_fill_self_tests(struct ef4_nic *efx,
break;
ef4_fill_test(n++, strings, data, &tests->phy_ext[i],
- "phy", 0, name, NULL);
+ "phy", 0, "%s", name);
}
}
diff --git a/drivers/net/ethernet/sfc/siena/ethtool_common.c b/drivers/net/ethernet/sfc/siena/ethtool_common.c
index 76cbce2b9592..9a8e39c5a113 100644
--- a/drivers/net/ethernet/sfc/siena/ethtool_common.c
+++ b/drivers/net/ethernet/sfc/siena/ethtool_common.c
@@ -206,9 +206,9 @@ int efx_siena_ethtool_set_pauseparam(struct net_device *net_dev,
*
* Fill in an individual self-test entry.
*/
-static void efx_fill_test(unsigned int test_index, u8 *strings, u64 *data,
- int *test, const char *unit_format, int unit_id,
- const char *test_format, const char *test_id)
+static void __printf(7, 8)
+efx_fill_test(unsigned int test_index, u8 *strings, u64 *data, int *test,
+ const char *unit_format, int unit_id, const char *test_format, ...)
{
char unit_str[ETH_GSTRING_LEN], test_str[ETH_GSTRING_LEN];
@@ -218,12 +218,16 @@ static void efx_fill_test(unsigned int test_index, u8 *strings, u64 *data,
/* Fill string, if applicable */
if (strings) {
+ va_list args;
+
if (strchr(unit_format, '%'))
snprintf(unit_str, sizeof(unit_str),
unit_format, unit_id);
else
strcpy(unit_str, unit_format);
- snprintf(test_str, sizeof(test_str), test_format, test_id);
+ va_start(args, test_format);
+ vsnprintf(test_str, sizeof(test_str), test_format, args);
+ va_end(args);
snprintf(strings + test_index * ETH_GSTRING_LEN,
ETH_GSTRING_LEN,
"%-6s %-24s", unit_str, test_str);
@@ -301,28 +305,28 @@ static int efx_ethtool_fill_self_tests(struct efx_nic *efx,
enum efx_loopback_mode mode;
efx_fill_test(n++, strings, data, &tests->phy_alive,
- "phy", 0, "alive", NULL);
+ "phy", 0, "alive");
efx_fill_test(n++, strings, data, &tests->nvram,
- "core", 0, "nvram", NULL);
+ "core", 0, "nvram");
efx_fill_test(n++, strings, data, &tests->interrupt,
- "core", 0, "interrupt", NULL);
+ "core", 0, "interrupt");
/* Event queues */
efx_for_each_channel(channel, efx) {
efx_fill_test(n++, strings, data,
&tests->eventq_dma[channel->channel],
EFX_CHANNEL_NAME(channel),
- "eventq.dma", NULL);
+ "eventq.dma");
efx_fill_test(n++, strings, data,
&tests->eventq_int[channel->channel],
EFX_CHANNEL_NAME(channel),
- "eventq.int", NULL);
+ "eventq.int");
}
efx_fill_test(n++, strings, data, &tests->memory,
- "core", 0, "memory", NULL);
+ "core", 0, "memory");
efx_fill_test(n++, strings, data, &tests->registers,
- "core", 0, "registers", NULL);
+ "core", 0, "registers");
for (i = 0; true; ++i) {
const char *name;
@@ -332,7 +336,8 @@ static int efx_ethtool_fill_self_tests(struct efx_nic *efx,
if (name == NULL)
break;
- efx_fill_test(n++, strings, data, &tests->phy_ext[i], "phy", 0, name, NULL);
+ efx_fill_test(n++, strings, data, &tests->phy_ext[i], "phy",
+ 0, "%s", name);
}
/* Loopback tests */
--
2.39.5