[dpdk-dev] [PATCH 1/4] eal: fix hotplug add and hotplug remove

[Qi Zhang]

If hotplug add an already plugged PCI device, it will
cause rte_pci_device->device.name be corrupted due to unexpected
rte_devargs_remove. Also if try to hotplug remove an already
unplugged device, it will cause segment fault due to unexpected
bus->unplug on a rte_device whose driver is NULL.
The patch fix these issues.

Fixes: 7e8b26650146 ("eal: fix hotplug add / remove")
Cc: stable at dpdk.org

Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
---
 lib/librte_eal/common/eal_common_dev.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
index 61cb3b162..0fa8c815d 100644
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -42,18 +42,6 @@ static struct dev_event_cb_list dev_event_cbs;
 /* spinlock for device callbacks */
 static rte_spinlock_t dev_event_lock = RTE_SPINLOCK_INITIALIZER;
 
-static int cmp_detached_dev_name(const struct rte_device *dev,
-	const void *_name)
-{
-	const char *name = _name;
-
-	/* skip attached devices */
-	if (dev->driver != NULL)
-		return 1;
-
-	return strcmp(dev->name, name);
-}
-
 static int cmp_dev_name(const struct rte_device *dev, const void *_name)
 {
 	const char *name = _name;
@@ -151,14 +139,19 @@ int __rte_experimental rte_eal_hotplug_add(const char *busname, const char *devn
 	if (ret)
 		goto err_devarg;
 
-	dev = bus->find_device(NULL, cmp_detached_dev_name, devname);
+	dev = bus->find_device(NULL, cmp_dev_name, devname);
 	if (dev == NULL) {
-		RTE_LOG(ERR, EAL, "Cannot find unplugged device (%s)\n",
+		RTE_LOG(ERR, EAL, "Cannot find device (%s)\n",
 			devname);
 		ret = -ENODEV;
 		goto err_devarg;
 	}
 
+	if (dev->driver != NULL) {
+		RTE_LOG(ERR, EAL, "Device is already plugged\n");
+		return -EEXIST;
+	}
+
 	ret = bus->plug(dev);
 	if (ret) {
 		RTE_LOG(ERR, EAL, "Driver cannot attach the device (%s)\n",
@@ -200,6 +193,11 @@ rte_eal_hotplug_remove(const char *busname, const char *devname)
 		return -EINVAL;
 	}
 
+	if (dev->driver == NULL) {
+		RTE_LOG(ERR, EAL, "Device is already unplugged\n");
+		return -ENOENT;
+	}
+
 	ret = bus->unplug(dev);
 	if (ret)
 		RTE_LOG(ERR, EAL, "Driver cannot detach the device (%s)\n",
-- 
2.13.6