[PATCH 4.19 07/48] net/mlx4_core: Fix use of ENOSPC around mlx4_counter_alloc()

Greg Kroah-Hartman
2020-05-13T10:05:29Z

From: Tariq Toukan <tariqt@mellanox.com>

[ Upstream commit 40e473071dbad04316ddc3613c3a3d1c75458299 ]

When ENOSPC is set the idx is still valid and gets set to the global
MLX4_SINK_COUNTER_INDEX. However gcc's static analysis cannot tell that
ENOSPC is impossible from mlx4_cmd_imm() and gives this warning:

drivers/net/ethernet/mellanox/mlx4/main.c:2552:28: warning: 'idx' may be
used uninitialized in this function [-Wmaybe-uninitialized]
2552 | priv->def_counter[port] = idx;

Also, when ENOSPC is returned mlx4_allocate_default_counters should not
fail.

Fixes: 6de5f7f6a1fa ("net/mlx4_core: Allocate default counter per port")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/mellanox/mlx4/main.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -2539,6 +2539,7 @@ static int mlx4_allocate_default_counter

if (!err || err == -ENOSPC) {
priv->def_counter[port] = idx;
+ err = 0;
} else if (err == -ENOENT) {
err = 0;
continue;
@@ -2589,7 +2590,8 @@ int mlx4_counter_alloc(struct mlx4_dev *
MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
if (!err)
*idx = get_param_l(&out_param);
-
+ if (WARN_ON(err == -ENOSPC))
+ err = -EINVAL;
return err;
}
return __mlx4_counter_alloc(dev, idx);