net/mlx4_core: Fix GEN_EQE accessing uninitialixed mutex

We occasionally see in procedure mlx4_GEN_EQE that the driver tries
to grab an uninitialized mutex.

This can occur in only one of two ways:
1. We are trying to generate an async event on an uninitialized slave.
2. We are trying to generate an async event on an illegal slave number
   ( < 0 or > persist->num_vfs) or an inactive slave.

To deal with #1: move the mutex initialization from specific slave init
sequence in procedure mlx_master_do_cmd to mlx4_multi_func_init() (so that
the mutex is always initialized for all slaves).

To deal with #2: check in procedure mlx4_GEN_EQE that the slave number
provided is in the proper range and that the slave is active.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 14 insertions, 12 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c
index a681d7c0bb9f..3350721bf515 100644
--- a/drivers/net/ethernet/mellanox/mlx4/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c
@@ -1993,7 +1993,6 @@ static void mlx4_master_do_cmd(struct mlx4_dev *dev, int slave, u8 cmd,
                         goto reset_slave;
                 slave_state[slave].vhcr_dma = ((u64) param) << 48;
                 priv->mfunc.master.slave_state[slave].cookie = 0;
-                mutex_init(&priv->mfunc.master.gen_eqe_mutex[slave]);
                 break;
         case MLX4_COMM_CMD_VHCR1:
                 if (slave_state[slave].last_cmd != MLX4_COMM_CMD_VHCR0)
@@ -2225,6 +2224,7 @@ int mlx4_multi_func_init(struct mlx4_dev *dev)
                 for (i = 0; i < dev->num_slaves; ++i) {
                         s_state = &priv->mfunc.master.slave_state[i];
                         s_state->last_cmd = MLX4_COMM_CMD_RESET;
+                        mutex_init(&priv->mfunc.master.gen_eqe_mutex[i]);
                         for (j = 0; j < MLX4_EVENT_TYPES_NUM; ++j)
                                 s_state->event_eq[j].eqn = -1;
                         __raw_writel((__force u32) 0,
diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c b/drivers/net/ethernet/mellanox/mlx4/eq.c
index 264bc15c1ff2..6e70ffee8e87 100644
--- a/drivers/net/ethernet/mellanox/mlx4/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/eq.c
@@ -153,12 +153,10 @@ void mlx4_gen_slave_eqe(struct work_struct *work)
 
                 /* All active slaves need to receive the event */
                 if (slave == ALL_SLAVES) {
-                        for (i = 0; i < dev->num_slaves; i++) {
-                                if (i != dev->caps.function &&
-                                    master->slave_state[i].active)
-                                        if (mlx4_GEN_EQE(dev, i, eqe))
-                                                mlx4_warn(dev, "Failed to generate event for slave %d\n",
-                                                          i);
+                        for (i = 0; i <= dev->persist->num_vfs; i++) {
+                                if (mlx4_GEN_EQE(dev, i, eqe))
+                                        mlx4_warn(dev, "Failed to generate event for slave %d\n",
+                                                  i);
                         }
                 } else {
                         if (mlx4_GEN_EQE(dev, slave, eqe))
@@ -203,13 +201,11 @@ static void mlx4_slave_event(struct mlx4_dev *dev, int slave,
                              struct mlx4_eqe *eqe)
 {
         struct mlx4_priv *priv = mlx4_priv(dev);
-        struct mlx4_slave_state *s_slave =
-                &priv->mfunc.master.slave_state[slave];
 
-        if (!s_slave->active) {
-                /*mlx4_warn(dev, "Trying to pass event to inactive slave\n");*/
+        if (slave < 0 || slave > dev->persist->num_vfs ||
+            slave == dev->caps.function ||
+            !priv->mfunc.master.slave_state[slave].active)
                 return;
-        }
 
         slave_event(dev, slave, eqe);
 }
diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
index d97ca88c55b5..6e413ac4e940 100644
--- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
+++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
@@ -3095,6 +3095,12 @@ int mlx4_GEN_EQE(struct mlx4_dev *dev, int slave, struct mlx4_eqe *eqe)
         if (!priv->mfunc.master.slave_state)
                 return -EINVAL;
 
+        /* check for slave valid, slave not PF, and slave active */
+        if (slave < 0 || slave > dev->persist->num_vfs ||
+            slave == dev->caps.function ||
+            !priv->mfunc.master.slave_state[slave].active)
+                return 0;
+
         event_eq = &priv->mfunc.master.slave_state[slave].event_eq[eqe->type];
 
         /* Create the event only if the slave is registered */