[dpdk-dev] [PATCH v2 2/2] bus/vdev: fix find device implementation

[Gaetan Rivet <gaetan.rivet@6wind.com>]

If start is set and a device before it matches the data,
this device is returned.

This induces potentially infinite loops.

Fixes: c7fe1eea8a74 ("bus: simplify finding starting point")
Cc: stable@dpdk.org

Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
---
 drivers/bus/vdev/rte_bus_vdev.h |  3 +++
 drivers/bus/vdev/vdev.c         | 14 +++++++++-----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/vdev/rte_bus_vdev.h b/drivers/bus/vdev/rte_bus_vdev.h
index 646d6c090..f9b5eb596 100644
--- a/drivers/bus/vdev/rte_bus_vdev.h
+++ b/drivers/bus/vdev/rte_bus_vdev.h
@@ -25,6 +25,9 @@ struct rte_vdev_device {
 #define RTE_DEV_TO_VDEV(ptr) \
 	container_of(ptr, struct rte_vdev_device, device)
 
+#define RTE_DEV_TO_VDEV_CONST(ptr) \
+	container_of(ptr, const struct rte_vdev_device, device)
+
 static inline const char *
 rte_vdev_device_name(const struct rte_vdev_device *dev)
 {
diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index 84fa51f98..9f576eb80 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -495,16 +495,20 @@ static struct rte_device *
 vdev_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
 		 const void *data)
 {
+	const struct rte_vdev_device *vstart;
 	struct rte_vdev_device *dev;
 
 	rte_spinlock_lock(&vdev_device_list_lock);
-	TAILQ_FOREACH(dev, &vdev_device_list, next) {
-		if (start && &dev->device == start) {
-			start = NULL;
-			continue;
-		}
+	if (start != NULL) {
+		vstart = RTE_DEV_TO_VDEV_CONST(start);
+		dev = TAILQ_NEXT(vstart, next);
+	} else {
+		dev = TAILQ_FIRST(&vdev_device_list);
+	}
+	while (dev != NULL) {
 		if (cmp(&dev->device, data) == 0)
 			break;
+		dev = TAILQ_NEXT(dev, next);
 	}
 	rte_spinlock_unlock(&vdev_device_list_lock);
 
-- 
2.11.0