diff mbox series

[net-next,1/2] mlxsw: core_thermal: Fix -Wformat-truncation warning

Message ID 514fb967f6f875fe7d856f4b91c94e4117e2053c.1696600763.git.petrm@nvidia.com (mailing list archive)
State Accepted
Commit 83b2d81b691ce0efdd4087c510d33087c2474da1
Delegated to: Netdev Maintainers
Headers show
Series mlxsw: Fix -Wformat-truncation warnings | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1362 this patch: 1362
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang fail Errors and warnings before: 17 this patch: 17
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 19 this patch: 17
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Petr Machata Oct. 6, 2023, 2:43 p.m. UTC 
From: Ido Schimmel <idosch@nvidia.com>

The name of a thermal zone device cannot be longer than 19 characters
('THERMAL_NAME_LENGTH - 1'). The format string 'mlxsw-lc%d-gearbox%d'
can exceed this limitation if the maximum number of line cards and the
maximum number of gearboxes on each line card cannot be represented
using a single digit.

This is not the case with current systems nor future ones. Therefore,
increase the size of the result buffer beyond 'THERMAL_NAME_LENGTH' and
suppress the following build warning [1].

If this limitation is ever exceeded, we will know about it since the
thermal core validates the thermal device's name during registration.

[1]
drivers/net/ethernet/mellanox/mlxsw/core_thermal.c: In function ‘mlxsw_thermal_gearboxes_init.constprop’:
drivers/net/ethernet/mellanox/mlxsw/core_thermal.c:543:71: error: ‘%d’ directive output may be truncated writing between 1 and 3 bytes into a region of size between 1 and 3
[-Werror=format-truncation=]
  543 |                 snprintf(tz_name, sizeof(tz_name), "mlxsw-lc%d-gearbox%d",
      |                                                                       ^~
In function ‘mlxsw_thermal_gearbox_tz_init’,
    inlined from ‘mlxsw_thermal_gearboxes_init.constprop’ at drivers/net/ethernet/mellanox/mlxsw/core_thermal.c:611:9:
drivers/net/ethernet/mellanox/mlxsw/core_thermal.c:543:52: note: directive argument in the range [1, 255]
  543 |                 snprintf(tz_name, sizeof(tz_name), "mlxsw-lc%d-gearbox%d",
      |                                                    ^~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlxsw/core_thermal.c:543:17: note: ‘snprintf’ output between 19 and 23 bytes into a destination of size 20
  543 |                 snprintf(tz_name, sizeof(tz_name), "mlxsw-lc%d-gearbox%d",
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  544 |                          gearbox_tz->slot_index, gearbox_tz->module + 1);
      |                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlxsw/core_thermal.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
index f709e44c76a8..f1b48d6615f6 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
@@ -536,7 +536,7 @@  mlxsw_thermal_modules_fini(struct mlxsw_thermal *thermal,
 static int
 mlxsw_thermal_gearbox_tz_init(struct mlxsw_thermal_module *gearbox_tz)
 {
-	char tz_name[THERMAL_NAME_LENGTH];
+	char tz_name[40];
 	int ret;
 
 	if (gearbox_tz->slot_index)