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

[Jonathan Erb]

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: sta...@dpdk.org

Signed-off-by: Jonathan Erb <jonathan....@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