[PATCH] net/mlx5: fix GCC uninitialized variable warning
From: Dmitry Kozlyuk <hidden>
Date: 2021-12-28 09:17:25
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
When building with -Db_sanitize=thread, GCC gives a warning:
drivers/net/mlx5/mlx5_flow_meter.c: In function ‘mlx5_flow_meter_create’:
drivers/net/mlx5/mlx5_flow_meter.c:1170:33: warning: ‘legacy_fm’ may be
used uninitialized in this function [-Wmaybe-uninitialized]
This is a false-positive: legacy_fm is initialized and used
if and only if priv->sh->meter_aso_en is false.
Work around this by initializing legacy_fm to NULL.
Add an assertion before legacy_fm use in case the logic changes.
Fixes: 444320186393 ("net/mlx5: support meter creation with policy")
Cc: lizh@nvidia.com
Cc: stable@dpdk.org
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Dmitry Kozlyuk <redacted>
Acked-by: Matan Azrad <redacted>
---
drivers/net/mlx5/mlx5_flow_meter.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/mlx5/mlx5_flow_meter.c b/drivers/net/mlx5/mlx5_flow_meter.c
index f4a7b697e6..fd4f286deb 100644
--- a/drivers/net/mlx5/mlx5_flow_meter.c
+++ b/drivers/net/mlx5/mlx5_flow_meter.c@@ -1167,7 +1167,8 @@ mlx5_flow_meter_create(struct rte_eth_dev *dev, uint32_t meter_id, struct mlx5_legacy_flow_meters *fms = &priv->flow_meters; struct mlx5_flow_meter_profile *fmp; struct mlx5_flow_meter_info *fm; - struct mlx5_legacy_flow_meter *legacy_fm; + /* GCC fails to infer legacy_fm is set when !priv->sh->meter_aso_en. */ + struct mlx5_legacy_flow_meter *legacy_fm = NULL; struct mlx5_flow_meter_policy *mtr_policy = NULL; struct mlx5_indexed_pool_config flow_ipool_cfg = { .size = 0,
@@ -1273,8 +1274,10 @@ mlx5_flow_meter_create(struct rte_eth_dev *dev, uint32_t meter_id, if (mlx5_flow_create_mtr_tbls(dev, fm, mtr_idx, domain_bitmap)) goto error; /* Add to the flow meter list. */ - if (!priv->sh->meter_aso_en) + if (!priv->sh->meter_aso_en) { + MLX5_ASSERT(legacy_fm != NULL); TAILQ_INSERT_TAIL(fms, legacy_fm, next); + } /* Add to the flow meter list. */ fm->active_state = 1; /* Config meter starts as active. */ fm->is_enable = 1;
--
2.25.1