[PATCH RESEND v7 1/5] drivers/bus: restore driver assignment at front of probing

[Huisong Li <lihuisong@huawei.com>]

The driver assignment was moved back at the end of the device probing
because there is no something to use rte_driver during the phase of
probing. See commit 391797f04208 ("drivers/bus: move driver assignment
to end of probing")

However, it is necessary for probing callback to reference rte_driver
before probing. For example, probing callback may call some APIs which
access the rte_pci_driver::driver by the device::driver pointer to get
driver information. In this case, a segment fault will occur in probing
callback if there is not this assignment.

Further, some comments in code need to be updated if we do that. The
driver pointer in rte_device is set before probing and needs to be reset
if probing failed. And rte_dev_is_probed can not be called inside probing.

Fixes: 391797f04208 ("drivers/bus: move driver assignment to end of probing")
Cc: stable@dpdk.org

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Acked-by: Chengwen Feng <fengchengwen@huawei.com>
---
 drivers/bus/auxiliary/auxiliary_common.c |  9 +++++++--
 drivers/bus/dpaa/dpaa_bus.c              |  9 +++++++--
 drivers/bus/fslmc/fslmc_bus.c            |  8 +++++++-
 drivers/bus/ifpga/ifpga_bus.c            | 12 +++++++++---
 drivers/bus/pci/pci_common.c             |  9 +++++++--
 drivers/bus/vdev/vdev.c                  | 10 ++++++++--
 drivers/bus/vmbus/vmbus_common.c         |  9 +++++++--
 7 files changed, 52 insertions(+), 14 deletions(-)

diff --git a/drivers/bus/auxiliary/auxiliary_common.c b/drivers/bus/auxiliary/auxiliary_common.c
index e6cbc4d356..8ce41a38d9 100644
--- a/drivers/bus/auxiliary/auxiliary_common.c
+++ b/drivers/bus/auxiliary/auxiliary_common.c
@@ -132,16 +132,21 @@ rte_auxiliary_probe_one_driver(struct rte_auxiliary_driver *drv,
 	}
 
 	dev->driver = drv;
+	/*
+	 * Reference rte_driver before probing so as to this pointer can
+	 * be used to get driver information in case of segment fault in
+	 * probing callback.
+	 */
+	dev->device.driver = &drv->driver;
 
 	AUXILIARY_LOG(INFO, "Probe auxiliary driver: %s device: %s (NUMA node %i)",
 		      drv->driver.name, dev->name, dev->device.numa_node);
 	ret = drv->probe(drv, dev);
 	if (ret != 0) {
 		dev->driver = NULL;
+		dev->device.driver = NULL;
 		rte_intr_instance_free(dev->intr_handle);
 		dev->intr_handle = NULL;
-	} else {
-		dev->device.driver = &drv->driver;
 	}
 
 	return ret;
diff --git a/drivers/bus/dpaa/dpaa_bus.c b/drivers/bus/dpaa/dpaa_bus.c
index 1f6997c77e..eae2a03ff3 100644
--- a/drivers/bus/dpaa/dpaa_bus.c
+++ b/drivers/bus/dpaa/dpaa_bus.c
@@ -697,17 +697,22 @@ rte_dpaa_bus_probe(void)
 			    (dev->device.devargs &&
 			     dev->device.devargs->policy == RTE_DEV_BLOCKED))
 				continue;
-
+			/*
+			 * Reference rte_driver before probing so as to this
+			 * pointer can be used to get driver information in case
+			 * of segment fault in probing callback.
+			 */
+			dev->device.driver = &drv->driver;
 			if (probe_all ||
 			    (dev->device.devargs &&
 			     dev->device.devargs->policy == RTE_DEV_ALLOWED)) {
 				ret = drv->probe(drv, dev);
 				if (ret) {
+					dev->device.driver = NULL;
 					DPAA_BUS_ERR("unable to probe:%s",
 						     dev->name);
 				} else {
 					dev->driver = drv;
-					dev->device.driver = &drv->driver;
 				}
 			}
 			break;
diff --git a/drivers/bus/fslmc/fslmc_bus.c b/drivers/bus/fslmc/fslmc_bus.c
index c155f4a2fd..db13b1d60c 100644
--- a/drivers/bus/fslmc/fslmc_bus.c
+++ b/drivers/bus/fslmc/fslmc_bus.c
@@ -472,15 +472,21 @@ rte_fslmc_probe(void)
 				continue;
 			}
 
+			/*
+			 * Reference rte_driver before probing so as to this
+			 * pointer can be used to get driver information in case
+			 * of segment fault in probing callback.
+			 */
+			dev->device.driver = &drv->driver;
 			if (probe_all ||
 			   (dev->device.devargs &&
 			    dev->device.devargs->policy == RTE_DEV_ALLOWED)) {
 				ret = drv->probe(drv, dev);
 				if (ret) {
+					dev->device.driver = NULL;
 					DPAA2_BUS_ERR("Unable to probe");
 				} else {
 					dev->driver = drv;
-					dev->device.driver = &drv->driver;
 				}
 			}
 			break;
diff --git a/drivers/bus/ifpga/ifpga_bus.c b/drivers/bus/ifpga/ifpga_bus.c
index ffb0c61214..bfe7077645 100644
--- a/drivers/bus/ifpga/ifpga_bus.c
+++ b/drivers/bus/ifpga/ifpga_bus.c
@@ -294,13 +294,19 @@ ifpga_probe_one_driver(struct rte_afu_driver *drv,
 
 	/* reference driver structure */
 	afu_dev->driver = drv;
+	/*
+	 * Reference rte_driver before probing so as to this pointer can
+	 * be used to get driver information in case of segment fault in
+	 * probing callback.
+	 */
+	afu_dev->device.driver = &drv->driver;
 
 	/* call the driver probe() function */
 	ret = drv->probe(afu_dev);
-	if (ret)
+	if (ret) {
 		afu_dev->driver = NULL;
-	else
-		afu_dev->device.driver = &drv->driver;
+		afu_dev->device.driver = NULL;
+	}
 
 	return ret;
 }
diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
index 1173f0887c..0a237a04cf 100644
--- a/drivers/bus/pci/pci_common.c
+++ b/drivers/bus/pci/pci_common.c
@@ -297,6 +297,12 @@ rte_pci_probe_one_driver(struct rte_pci_driver *dr,
 				return ret;
 			}
 		}
+		/*
+		 * Reference rte_driver before probing so as to this pointer can
+		 * be used to get driver information in case of segment fault in
+		 * probing callback.
+		 */
+		dev->device.driver = &dr->driver;
 	}
 
 	PCI_LOG(INFO, "Probe PCI driver: %s (%x:%04x) device: "PCI_PRI_FMT" (socket %i)",
@@ -309,6 +315,7 @@ rte_pci_probe_one_driver(struct rte_pci_driver *dr,
 		return ret; /* no rollback if already succeeded earlier */
 	if (ret) {
 		dev->driver = NULL;
+		dev->device.driver = NULL;
 		if ((dr->drv_flags & RTE_PCI_DRV_NEED_MAPPING) &&
 			/* Don't unmap if device is unsupported and
 			 * driver needs mapped resources.
@@ -320,8 +327,6 @@ rte_pci_probe_one_driver(struct rte_pci_driver *dr,
 		dev->vfio_req_intr_handle = NULL;
 		rte_intr_instance_free(dev->intr_handle);
 		dev->intr_handle = NULL;
-	} else {
-		dev->device.driver = &dr->driver;
 	}
 
 	return ret;
diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index ec7abe7cda..2bf8e1f7fe 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -207,9 +207,15 @@ vdev_probe_all_drivers(struct rte_vdev_device *dev)
 		return -1;
 	}
 
+	/*
+	 * Reference rte_driver before probing so as to this pointer can
+	 * be used to get driver information in case of segment fault in
+	 * probing callback.
+	 */
+	dev->device.driver = &driver->driver;
 	ret = driver->probe(dev);
-	if (ret == 0)
-		dev->device.driver = &driver->driver;
+	if (ret != 0)
+		dev->device.driver = NULL;
 	return ret;
 }
 
diff --git a/drivers/bus/vmbus/vmbus_common.c b/drivers/bus/vmbus/vmbus_common.c
index b9139c6e6c..0238f15f4f 100644
--- a/drivers/bus/vmbus/vmbus_common.c
+++ b/drivers/bus/vmbus/vmbus_common.c
@@ -119,6 +119,12 @@ vmbus_probe_one_driver(struct rte_vmbus_driver *dr,
 
 	/* reference driver structure */
 	dev->driver = dr;
+	/*
+	 * Reference rte_driver before probing so as to this pointer can
+	 * be used to get driver information in case of segment fault in
+	 * probing callback.
+	 */
+	dev->device.driver = &dr->driver;
 
 	if (dev->device.numa_node < 0 && rte_socket_count() > 1)
 		VMBUS_LOG(INFO, "Device %s is not NUMA-aware", guid);
@@ -128,9 +134,8 @@ vmbus_probe_one_driver(struct rte_vmbus_driver *dr,
 	ret = dr->probe(dr, dev);
 	if (ret) {
 		dev->driver = NULL;
+		dev->device.driver = NULL;
 		rte_vmbus_unmap_device(dev);
-	} else {
-		dev->device.driver = &dr->driver;
 	}
 
 	return ret;
-- 
2.33.0