From: Arnd Bergmann <arnd@kernel.org>
To: Edward Cree <ecree.xilinx@gmail.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Nathan Chancellor <nathan@kernel.org>,
Jeff Garzik <jgarzik@redhat.com>,
Ben Hutchings <bhutchings@solarflare.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
Brett Creeley <brett.creeley@amd.com>,
Breno Leitao <leitao@debian.org>, Kees Cook <kees@kernel.org>,
netdev@vger.kernel.org, linux-net-drivers@amd.com,
linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: [PATCH] [v2] net: sfc: avoid format string warning
Date: Wed, 25 Mar 2026 14:45:44 +0100 [thread overview]
Message-ID: <20260325134557.3406655-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
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 a non-varargs unit name that gets pre-filled by
the caller, so that the compiler can validate all format strings.
Fixes: 3273c2e8c66a ("[netdrvr] sfc: sfc: Add self-test support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2: open-code the unit name format as well
reformat the function prototype
---
drivers/net/ethernet/sfc/ethtool_common.c | 67 +++++++++---------
drivers/net/ethernet/sfc/falcon/ethtool.c | 68 +++++++++---------
.../net/ethernet/sfc/siena/ethtool_common.c | 69 +++++++++----------
3 files changed, 99 insertions(+), 105 deletions(-)
diff --git a/drivers/net/ethernet/sfc/ethtool_common.c b/drivers/net/ethernet/sfc/ethtool_common.c
index 54f8e4626568..62a94c995241 100644
--- a/drivers/net/ethernet/sfc/ethtool_common.c
+++ b/drivers/net/ethernet/sfc/ethtool_common.c
@@ -247,18 +247,17 @@ int efx_ethtool_set_pauseparam(struct net_device *net_dev,
* @strings: Ethtool strings, or %NULL
* @data: Ethtool test results, or %NULL
* @test: Pointer to test result (used only if data != %NULL)
- * @unit_format: Unit name format (e.g. "chan\%d")
- * @unit_id: Unit id (e.g. 0 for "chan0")
+ * @unit_name: Unit name
* @test_format: Test name format (e.g. "loopback.\%s.tx.sent")
- * @test_id: Test id (e.g. "PHYXS" for "loopback.PHYXS.tx_sent")
*
* 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(6, 7) efx_fill_test(unsigned int test_index, u8 *strings,
+ u64 *data, int *test,
+ const char *unit_name,
+ const char *test_format, ...)
{
- char unit_str[ETH_GSTRING_LEN], test_str[ETH_GSTRING_LEN];
+ char test_str[ETH_GSTRING_LEN];
/* Fill data value, if applicable */
if (data)
@@ -266,20 +265,16 @@ static void efx_fill_test(unsigned int test_index, u8 *strings, u64 *data,
/* Fill string, if applicable */
if (strings) {
- 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_list args;
+
+ 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);
+ ETH_GSTRING_LEN, "%-6s %-24s", unit_name, test_str);
}
}
-#define EFX_CHANNEL_NAME(_channel) "chan%d", _channel->channel
-#define EFX_TX_QUEUE_NAME(_tx_queue) "txq%d", _tx_queue->label
#define EFX_LOOPBACK_NAME(_mode, _counter) \
"loopback.%s." _counter, STRING_TABLE_LOOKUP(_mode, efx_loopback_mode)
@@ -306,23 +301,23 @@ static int efx_fill_loopback_test(struct efx_nic *efx,
struct efx_tx_queue *tx_queue;
efx_for_each_channel_tx_queue(tx_queue, channel) {
+ char unit_str[ETH_GSTRING_LEN];
+
+ snprintf(unit_str, sizeof(unit_str), "txq%d", tx_queue->label);
+
efx_fill_test(test_index++, strings, data,
&lb_tests->tx_sent[tx_queue->label],
- EFX_TX_QUEUE_NAME(tx_queue),
- EFX_LOOPBACK_NAME(mode, "tx_sent"));
+ unit_str, EFX_LOOPBACK_NAME(mode, "tx_sent"));
efx_fill_test(test_index++, strings, data,
&lb_tests->tx_done[tx_queue->label],
- EFX_TX_QUEUE_NAME(tx_queue),
- EFX_LOOPBACK_NAME(mode, "tx_done"));
+ unit_str, EFX_LOOPBACK_NAME(mode, "tx_done"));
}
efx_fill_test(test_index++, strings, data,
&lb_tests->rx_good,
- "rx", 0,
- EFX_LOOPBACK_NAME(mode, "rx_good"));
+ "rx", EFX_LOOPBACK_NAME(mode, "rx_good"));
efx_fill_test(test_index++, strings, data,
&lb_tests->rx_bad,
- "rx", 0,
- EFX_LOOPBACK_NAME(mode, "rx_bad"));
+ "rx", EFX_LOOPBACK_NAME(mode, "rx_bad"));
return test_index;
}
@@ -349,28 +344,30 @@ 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", "alive");
efx_fill_test(n++, strings, data, &tests->nvram,
- "core", 0, "nvram", NULL);
+ "core", "nvram");
efx_fill_test(n++, strings, data, &tests->interrupt,
- "core", 0, "interrupt", NULL);
+ "core", "interrupt");
/* Event queues */
efx_for_each_channel(channel, efx) {
+ char unit_str[ETH_GSTRING_LEN];
+
+ snprintf(unit_str, sizeof(unit_str), "txq%d", channel->channel);
+
efx_fill_test(n++, strings, data,
&tests->eventq_dma[channel->channel],
- EFX_CHANNEL_NAME(channel),
- "eventq.dma", NULL);
+ unit_str, "eventq.dma");
efx_fill_test(n++, strings, data,
&tests->eventq_int[channel->channel],
- EFX_CHANNEL_NAME(channel),
- "eventq.int", NULL);
+ unit_str, "eventq.int");
}
efx_fill_test(n++, strings, data, &tests->memory,
- "core", 0, "memory", NULL);
+ "core", "memory");
efx_fill_test(n++, strings, data, &tests->registers,
- "core", 0, "registers", NULL);
+ "core", "registers");
for (i = 0; true; ++i) {
const char *name;
@@ -380,7 +377,7 @@ 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", "%s", name);
}
/* Loopback tests */
diff --git a/drivers/net/ethernet/sfc/falcon/ethtool.c b/drivers/net/ethernet/sfc/falcon/ethtool.c
index 807c587eba3b..260340b291d3 100644
--- a/drivers/net/ethernet/sfc/falcon/ethtool.c
+++ b/drivers/net/ethernet/sfc/falcon/ethtool.c
@@ -200,18 +200,17 @@ static void ef4_ethtool_set_msglevel(struct net_device *net_dev, u32 msg_enable)
* @strings: Ethtool strings, or %NULL
* @data: Ethtool test results, or %NULL
* @test: Pointer to test result (used only if data != %NULL)
- * @unit_format: Unit name format (e.g. "chan\%d")
- * @unit_id: Unit id (e.g. 0 for "chan0")
+ * @unit_name: Unit name
* @test_format: Test name format (e.g. "loopback.\%s.tx.sent")
- * @test_id: Test id (e.g. "PHYXS" for "loopback.PHYXS.tx_sent")
*
* Fill in an individual self-test entry.
*/
-static void 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)
+static void __printf(6, 7) ef4_fill_test(unsigned int test_index, u8 *strings,
+ u64 *data, int *test,
+ const char *unit_name,
+ const char *test_format, ...)
{
- char unit_str[ETH_GSTRING_LEN], test_str[ETH_GSTRING_LEN];
+ char test_str[ETH_GSTRING_LEN];
/* Fill data value, if applicable */
if (data)
@@ -219,21 +218,17 @@ static void ef4_fill_test(unsigned int test_index, u8 *strings, u64 *data,
/* Fill string, if applicable */
if (strings) {
- 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_list arg;
+
+ 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);
+ "%-6s %-24s", unit_name, test_str);
}
}
-#define EF4_CHANNEL_NAME(_channel) "chan%d", _channel->channel
-#define EF4_TX_QUEUE_NAME(_tx_queue) "txq%d", _tx_queue->queue
-#define EF4_RX_QUEUE_NAME(_rx_queue) "rxq%d", _rx_queue->queue
#define EF4_LOOPBACK_NAME(_mode, _counter) \
"loopback.%s." _counter, STRING_TABLE_LOOKUP(_mode, ef4_loopback_mode)
@@ -260,23 +255,23 @@ static int ef4_fill_loopback_test(struct ef4_nic *efx,
struct ef4_tx_queue *tx_queue;
ef4_for_each_channel_tx_queue(tx_queue, channel) {
+ char unit_str[ETH_GSTRING_LEN];
+
+ snprintf(unit_str, sizeof(unit_str), "txq%d", tx_queue->queue);
+
ef4_fill_test(test_index++, strings, data,
&lb_tests->tx_sent[tx_queue->queue],
- EF4_TX_QUEUE_NAME(tx_queue),
- EF4_LOOPBACK_NAME(mode, "tx_sent"));
+ unit_str, EF4_LOOPBACK_NAME(mode, "tx_sent"));
ef4_fill_test(test_index++, strings, data,
&lb_tests->tx_done[tx_queue->queue],
- EF4_TX_QUEUE_NAME(tx_queue),
- EF4_LOOPBACK_NAME(mode, "tx_done"));
+ unit_str, EF4_LOOPBACK_NAME(mode, "tx_done"));
}
ef4_fill_test(test_index++, strings, data,
&lb_tests->rx_good,
- "rx", 0,
- EF4_LOOPBACK_NAME(mode, "rx_good"));
+ "rx", EF4_LOOPBACK_NAME(mode, "rx_good"));
ef4_fill_test(test_index++, strings, data,
&lb_tests->rx_bad,
- "rx", 0,
- EF4_LOOPBACK_NAME(mode, "rx_bad"));
+ "rx", EF4_LOOPBACK_NAME(mode, "rx_bad"));
return test_index;
}
@@ -303,28 +298,31 @@ 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", "alive");
ef4_fill_test(n++, strings, data, &tests->nvram,
- "core", 0, "nvram", NULL);
+ "core", "nvram");
ef4_fill_test(n++, strings, data, &tests->interrupt,
- "core", 0, "interrupt", NULL);
+ "core", "interrupt");
/* Event queues */
ef4_for_each_channel(channel, efx) {
+ char unit_str[ETH_GSTRING_LEN];
+
+ snprintf(unit_str, sizeof(unit_str), "chan%d",
+ channel->channel);
+
ef4_fill_test(n++, strings, data,
&tests->eventq_dma[channel->channel],
- EF4_CHANNEL_NAME(channel),
- "eventq.dma", NULL);
+ unit_str, "eventq.dma");
ef4_fill_test(n++, strings, data,
&tests->eventq_int[channel->channel],
- EF4_CHANNEL_NAME(channel),
- "eventq.int", NULL);
+ unit_str, "eventq.int");
}
ef4_fill_test(n++, strings, data, &tests->memory,
- "core", 0, "memory", NULL);
+ "core", "memory");
ef4_fill_test(n++, strings, data, &tests->registers,
- "core", 0, "registers", NULL);
+ "core", "registers");
if (efx->phy_op->run_tests != NULL) {
EF4_BUG_ON_PARANOID(efx->phy_op->test_name == NULL);
@@ -338,7 +336,7 @@ 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", "%s", name);
}
}
diff --git a/drivers/net/ethernet/sfc/siena/ethtool_common.c b/drivers/net/ethernet/sfc/siena/ethtool_common.c
index 76cbce2b9592..e49cc604b43a 100644
--- a/drivers/net/ethernet/sfc/siena/ethtool_common.c
+++ b/drivers/net/ethernet/sfc/siena/ethtool_common.c
@@ -199,18 +199,17 @@ int efx_siena_ethtool_set_pauseparam(struct net_device *net_dev,
* @strings: Ethtool strings, or %NULL
* @data: Ethtool test results, or %NULL
* @test: Pointer to test result (used only if data != %NULL)
- * @unit_format: Unit name format (e.g. "chan\%d")
- * @unit_id: Unit id (e.g. 0 for "chan0")
+ * @unit_name: Unit name
* @test_format: Test name format (e.g. "loopback.\%s.tx.sent")
- * @test_id: Test id (e.g. "PHYXS" for "loopback.PHYXS.tx_sent")
*
* 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(6, 7) efx_fill_test(unsigned int test_index, u8 *strings,
+ u64 *data, int *test,
+ const char *unit_name,
+ char *test_format, ...)
{
- char unit_str[ETH_GSTRING_LEN], test_str[ETH_GSTRING_LEN];
+ char test_str[ETH_GSTRING_LEN];
/* Fill data value, if applicable */
if (data)
@@ -218,20 +217,16 @@ static void efx_fill_test(unsigned int test_index, u8 *strings, u64 *data,
/* Fill string, if applicable */
if (strings) {
- 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_list args;
+
+ 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);
+ ETH_GSTRING_LEN, "%-6s %-24s", unit_name, test_str);
}
}
-#define EFX_CHANNEL_NAME(_channel) "chan%d", _channel->channel
-#define EFX_TX_QUEUE_NAME(_tx_queue) "txq%d", _tx_queue->label
#define EFX_LOOPBACK_NAME(_mode, _counter) \
"loopback.%s." _counter, STRING_TABLE_LOOKUP(_mode, efx_siena_loopback_mode)
@@ -258,23 +253,23 @@ static int efx_fill_loopback_test(struct efx_nic *efx,
struct efx_tx_queue *tx_queue;
efx_for_each_channel_tx_queue(tx_queue, channel) {
+ char unit_str[ETH_GSTRING_LEN];
+
+ snprintf(unit_str, sizeof(unit_str), "txq%d",tx_queue->label);
+
efx_fill_test(test_index++, strings, data,
&lb_tests->tx_sent[tx_queue->label],
- EFX_TX_QUEUE_NAME(tx_queue),
- EFX_LOOPBACK_NAME(mode, "tx_sent"));
+ unit_str, EFX_LOOPBACK_NAME(mode, "tx_sent"));
efx_fill_test(test_index++, strings, data,
&lb_tests->tx_done[tx_queue->label],
- EFX_TX_QUEUE_NAME(tx_queue),
- EFX_LOOPBACK_NAME(mode, "tx_done"));
+ unit_str, EFX_LOOPBACK_NAME(mode, "tx_done"));
}
efx_fill_test(test_index++, strings, data,
&lb_tests->rx_good,
- "rx", 0,
- EFX_LOOPBACK_NAME(mode, "rx_good"));
+ "rx", EFX_LOOPBACK_NAME(mode, "rx_good"));
efx_fill_test(test_index++, strings, data,
&lb_tests->rx_bad,
- "rx", 0,
- EFX_LOOPBACK_NAME(mode, "rx_bad"));
+ "rx", EFX_LOOPBACK_NAME(mode, "rx_bad"));
return test_index;
}
@@ -301,28 +296,31 @@ 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", "alive");
efx_fill_test(n++, strings, data, &tests->nvram,
- "core", 0, "nvram", NULL);
+ "core", "nvram");
efx_fill_test(n++, strings, data, &tests->interrupt,
- "core", 0, "interrupt", NULL);
+ "core", "interrupt");
/* Event queues */
efx_for_each_channel(channel, efx) {
+ char unit_str[ETH_GSTRING_LEN];
+
+ snprintf(unit_str, sizeof(unit_str), "chan%d",
+ channel->channel);
+
efx_fill_test(n++, strings, data,
&tests->eventq_dma[channel->channel],
- EFX_CHANNEL_NAME(channel),
- "eventq.dma", NULL);
+ unit_str, "eventq.dma");
efx_fill_test(n++, strings, data,
&tests->eventq_int[channel->channel],
- EFX_CHANNEL_NAME(channel),
- "eventq.int", NULL);
+ unit_str, "eventq.int");
}
efx_fill_test(n++, strings, data, &tests->memory,
- "core", 0, "memory", NULL);
+ "core", "memory");
efx_fill_test(n++, strings, data, &tests->registers,
- "core", 0, "registers", NULL);
+ "core", "registers");
for (i = 0; true; ++i) {
const char *name;
@@ -332,7 +330,8 @@ 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",
+ "%s", name);
}
/* Loopback tests */
--
2.39.5
next reply other threads:[~2026-03-25 13:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-25 13:45 Arnd Bergmann [this message]
2026-03-26 2:00 ` [PATCH] [v2] net: sfc: avoid format string warning Edward Cree
2026-03-26 9:17 ` Breno Leitao
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