[dpdk-dev] [PATCH v2] bus/vmbus: Fix crash when handling packets in secondary process

[Jonathan Erb <jonathan.erb@banduracyber.com>]

Have secondary processes construct their own copy of primary channel with
own mappings.

Remove vmbus_channel primary ptr from struct mapped_vmbus_resource as its
not used.

Populate virtual memory address "addr" in struct rte_mem_resource for
secondary processes as netvsc will attempt to reference it thus causing
a crash. It was initialized for primary processes but not for secondary.
Cc: stable@dpdk.org

Signed-off-by: Jonathan Erb <jonathan.erb@banduracyber.com>
---
v2:
* Remove unnecessary check for NULL pointer before call to rte_free() 
per reviwer comment.

 drivers/bus/vmbus/private.h          |  1 -
 drivers/bus/vmbus/vmbus_channel.c    |  4 +---
 drivers/bus/vmbus/vmbus_common_uio.c | 14 +++++++++-----
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/bus/vmbus/private.h b/drivers/bus/vmbus/private.h
index 528d60a42f..746212bd5f 100644
--- a/drivers/bus/vmbus/private.h
+++ b/drivers/bus/vmbus/private.h
@@ -42,7 +42,6 @@ struct mapped_vmbus_resource {
 
 	rte_uuid_t id;
 	int nb_maps;
-	struct vmbus_channel *primary;
 	struct vmbus_map maps[VMBUS_MAX_RESOURCE];
 	char path[PATH_MAX];
 };
diff --git a/drivers/bus/vmbus/vmbus_channel.c b/drivers/bus/vmbus/vmbus_channel.c
index f67f1c438a..119b9b367e 100644
--- a/drivers/bus/vmbus/vmbus_channel.c
+++ b/drivers/bus/vmbus/vmbus_channel.c
@@ -351,10 +351,8 @@ int rte_vmbus_chan_open(struct rte_vmbus_device *device,
 
 	err = vmbus_chan_create(device, device->relid, 0,
 				device->monitor_id, new_chan);
-	if (!err) {
+	if (!err)
 		device->primary = *new_chan;
-		uio_res->primary = *new_chan;
-	}
 
 	return err;
 }
diff --git a/drivers/bus/vmbus/vmbus_common_uio.c b/drivers/bus/vmbus/vmbus_common_uio.c
index 8582e32c1d..83c56b6fa2 100644
--- a/drivers/bus/vmbus/vmbus_common_uio.c
+++ b/drivers/bus/vmbus/vmbus_common_uio.c
@@ -69,8 +69,10 @@ vmbus_uio_map_secondary(struct rte_vmbus_device *dev)
 					     fd, offset,
 					     uio_res->maps[i].size, 0);
 
-		if (mapaddr == uio_res->maps[i].addr)
+		if (mapaddr == uio_res->maps[i].addr) {
+			dev->resource[i].addr = mapaddr;
 			continue;	/* successful map */
+		}
 
 		if (mapaddr == MAP_FAILED)
 			VMBUS_LOG(ERR,
@@ -88,9 +90,9 @@ vmbus_uio_map_secondary(struct rte_vmbus_device *dev)
 	/* fd is not needed in secondary process, close it */
 	close(fd);
 
-	dev->primary = uio_res->primary;
-	if (!dev->primary) {
-		VMBUS_LOG(ERR, "missing primary channel");
+	if (vmbus_chan_create(dev, dev->relid, 0,
+					dev->monitor_id, &dev->primary)) {
+		VMBUS_LOG(ERR, "cannot create primary channel");
 		return -1;
 	}
 
@@ -211,8 +213,10 @@ vmbus_uio_unmap_resource(struct rte_vmbus_device *dev)
 		return;
 
 	/* secondary processes - just free maps */
-	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
+	if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
+		rte_free(dev->primary);
 		return vmbus_uio_unmap(uio_res);
+	}
 
 	TAILQ_REMOVE(uio_res_list, uio_res, next);
 
-- 
2.17.1