[PATCH] ibmvnic: Initialize completion variables before starting work

[PATCH] ibmvnic: Initialize completion variables before starting work

[Nathan Fontenot]

Initialize condition variables prior to invoking any work that can
mark them complete. This resolves a race in the ibmvnic driver where
the driver faults trying to complete an uninitialized condition
variable.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c |   17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index a024141..752b082 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -189,9 +189,10 @@ static int alloc_long_term_buff(struct ibmvnic_adapter *adapter,
 	}
 	ltb->map_id = adapter->map_id;
 	adapter->map_id++;
+
+	init_completion(&adapter->fw_done);
 	send_request_map(adapter, ltb->addr,
 			 ltb->size, ltb->map_id);
-	init_completion(&adapter->fw_done);
 	wait_for_completion(&adapter->fw_done);
 	return 0;
 }
@@ -1121,10 +1122,10 @@ static void ibmvnic_get_ethtool_stats(struct net_device *dev,
 	crq.request_statistics.ioba = cpu_to_be32(adapter->stats_token);
 	crq.request_statistics.len =
 	    cpu_to_be32(sizeof(struct ibmvnic_statistics));
-	ibmvnic_send_crq(adapter, &crq);
 
 	/* Wait for data to be written */
 	init_completion(&adapter->stats_done);
+	ibmvnic_send_crq(adapter, &crq);
 	wait_for_completion(&adapter->stats_done);
 
 	for (i = 0; i < ARRAY_SIZE(ibmvnic_stats); i++)
@@ -2799,9 +2800,9 @@ static ssize_t trace_read(struct file *file, char __user *user_buf, size_t len,
 	crq.collect_fw_trace.correlator = adapter->ras_comps[num].correlator;
 	crq.collect_fw_trace.ioba = cpu_to_be32(trace_tok);
 	crq.collect_fw_trace.len = adapter->ras_comps[num].trace_buff_size;
-	ibmvnic_send_crq(adapter, &crq);
 
 	init_completion(&adapter->fw_done);
+	ibmvnic_send_crq(adapter, &crq);
 	wait_for_completion(&adapter->fw_done);
 
 	if (*ppos + len > be32_to_cpu(adapter->ras_comps[num].trace_buff_size))
@@ -3581,9 +3582,9 @@ static int ibmvnic_dump_show(struct seq_file *seq, void *v)
 	memset(&crq, 0, sizeof(crq));
 	crq.request_dump_size.first = IBMVNIC_CRQ_CMD;
 	crq.request_dump_size.cmd = REQUEST_DUMP_SIZE;
-	ibmvnic_send_crq(adapter, &crq);
 
 	init_completion(&adapter->fw_done);
+	ibmvnic_send_crq(adapter, &crq);
 	wait_for_completion(&adapter->fw_done);
 
 	seq_write(seq, adapter->dump_data, adapter->dump_data_size);
@@ -3629,8 +3630,8 @@ static void handle_crq_init_rsp(struct work_struct *work)
 		}
 	}
 
-	send_version_xchg(adapter);
 	reinit_completion(&adapter->init_done);
+	send_version_xchg(adapter);
 	if (!wait_for_completion_timeout(&adapter->init_done, timeout)) {
 		dev_err(dev, "Passive init timeout\n");
 		goto task_failed;
@@ -3640,9 +3641,9 @@ static void handle_crq_init_rsp(struct work_struct *work)
 		if (adapter->renegotiate) {
 			adapter->renegotiate = false;
 			release_sub_crqs_no_irqs(adapter);
-			send_cap_queries(adapter);
 
 			reinit_completion(&adapter->init_done);
+			send_cap_queries(adapter);
 			if (!wait_for_completion_timeout(&adapter->init_done,
 							 timeout)) {
 				dev_err(dev, "Passive init timeout\n");
@@ -3772,9 +3773,9 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 			adapter->debugfs_dump = ent;
 		}
 	}
-	ibmvnic_send_crq_init(adapter);
 
 	init_completion(&adapter->init_done);
+	ibmvnic_send_crq_init(adapter);
 	if (!wait_for_completion_timeout(&adapter->init_done, timeout))
 		return 0;
 
@@ -3782,9 +3783,9 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 		if (adapter->renegotiate) {
 			adapter->renegotiate = false;
 			release_sub_crqs_no_irqs(adapter);
-			send_cap_queries(adapter);
 
 			reinit_completion(&adapter->init_done);
+			send_cap_queries(adapter);
 			if (!wait_for_completion_timeout(&adapter->init_done,
 							 timeout))
 				return 0;

Re: [PATCH] ibmvnic: Initialize completion variables before starting work

[David Miller]

From: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Date: Fri, 10 Feb 2017 13:45:05 -0500

> Initialize condition variables prior to invoking any work that can
> mark them complete. This resolves a race in the ibmvnic driver where
> the driver faults trying to complete an uninitialized condition
> variable.
> 
> Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>

Applied.