eal: fix multi-process hotplug if already probed

When primary process receives an IPC attach request
of a device that's already locally-attached, it
doesn't setup its variables properly and is prone to
segfaulting on a subsequent rollback.

`ret = local_dev_probe(req->devargs, &dev)`

The above function will set `dev` pointer to the
proper device *unless* it returns with error. One of
those errors is -EEXIST, which the hotplug function
explicitly ignores. For -EEXIST, it proceeds with
attaching the device and expects the dev pointer to
be valid.

This patch makes `local_dev_probe` set the dev pointer
even if it returns -EEXIST.

Fixes: ac9e4a17370f ("eal: support attach/detach shared device from secondary")

Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>

diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
index 1fdc9ab..a08dc08 100644 (file)
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -168,16 +168,14 @@ local_dev_probe(const char *devargs, struct rte_device **new_dev)
        }
 
        ret = dev->bus->plug(dev);
-       if (ret) {
-               if (rte_dev_is_probed(dev)) /* if already succeeded earlier */
-                       return ret; /* no rollback */
+       if (ret && !rte_dev_is_probed(dev)) { /* if hasn't ever succeeded */
                RTE_LOG(ERR, EAL, "Driver cannot attach the device (%s)\n",
                        dev->name);
                goto err_devarg;
        }
 
        *new_dev = dev;
-       return 0;
+       return ret;
 
 err_devarg:
        if (rte_devargs_remove(da) != 0) {