diff mbox

[dpdk-dev,v2,07/11] ethdev: add lock to port allocation check

Message ID 20180509224313.27289-8-thomas@monjalon.net (mailing list archive)
State Superseded, archived
Headers

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Thomas Monjalon May 9, 2018, 10:43 p.m. UTC 
  From: Matan Azrad <matan@mellanox.com>

When comparing the port name, there can be a race condition with
a thread allocating a new port and writing the name at the same time.
It can lead to match with a partial name by error.

The check of the port is now considered as a critical section
protected with locks.

This fix will be even more required for multi-process when the
port availability will rely only on the name, in a following patch.

Fixes: 84934303a17c ("ethdev: synchronize port allocation")
Cc: stable@dpdk.org

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
---
 lib/librte_ethdev/rte_ethdev.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

Comments

Andrew Rybchenko May 10, 2018, 10:44 a.m. UTC | #1 
On 05/10/2018 01:43 AM, Thomas Monjalon wrote:
> From: Matan Azrad <matan@mellanox.com>
>
> When comparing the port name, there can be a race condition with
> a thread allocating a new port and writing the name at the same time.
> It can lead to match with a partial name by error.
>
> The check of the port is now considered as a critical section
> protected with locks.
>
> This fix will be even more required for multi-process when the
> port availability will rely only on the name, in a following patch.
>
> Fixes: 84934303a17c ("ethdev: synchronize port allocation")
> Cc: stable@dpdk.org
>
> Signed-off-by: Matan Azrad <matan@mellanox.com>
> Acked-by: Thomas Monjalon <thomas@monjalon.net>

Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
diff mbox

Patch

diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 6ddae9960..4fa7400d5 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -227,8 +227,8 @@  rte_eth_dev_shared_data_prepare(void)
 	rte_spinlock_unlock(&rte_eth_shared_data_lock);
 }
 
-struct rte_eth_dev *
-rte_eth_dev_allocated(const char *name)
+static struct rte_eth_dev *
+rte_eth_dev_allocated_nolock(const char *name)
 {
 	unsigned i;
 
@@ -240,6 +240,22 @@  rte_eth_dev_allocated(const char *name)
 	return NULL;
 }
 
+struct rte_eth_dev *
+rte_eth_dev_allocated(const char *name)
+{
+	struct rte_eth_dev *ethdev;
+
+	rte_eth_dev_shared_data_prepare();
+
+	rte_spinlock_lock(&rte_eth_dev_shared_data->ownership_lock);
+
+	ethdev = rte_eth_dev_allocated_nolock(name);
+
+	rte_spinlock_unlock(&rte_eth_dev_shared_data->ownership_lock);
+
+	return ethdev;
+}
+
 static uint16_t
 rte_eth_dev_find_free_port(void)
 {
@@ -286,7 +302,7 @@  rte_eth_dev_allocate(const char *name)
 		goto unlock;
 	}
 
-	if (rte_eth_dev_allocated(name) != NULL) {
+	if (rte_eth_dev_allocated_nolock(name) != NULL) {
 		ethdev_log(ERR,
 			"Ethernet Device with name %s already allocated!",
 			name);