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.
Despite this patch being a fix, it also introduces
a design decision - when any secondary process fails
to attach a device, the primary process that already
had the device attached won't attempt to detach that
device locally as a part of the rollback routine.
Primary process would have already printed a message
"Failed to [...] on secondary" and now it will also
print a warning "Devices may not be in sync [...]".
Fixes: ac9e4a17370f ("eal: support attach/detach shared device from secondary")
Cc: qi.z.zh...@intel.com
Signed-off-by: Darek Stojaczyk <dariusz.stojac...@intel.com>
---
lib/librte_eal/common/hotplug_mp.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/lib/librte_eal/common/hotplug_mp.c
b/lib/librte_eal/common/hotplug_mp.c
index 7c9fcc46c..7ee074a31 100644
--- a/lib/librte_eal/common/hotplug_mp.c
+++ b/lib/librte_eal/common/hotplug_mp.c
@@ -88,7 +88,7 @@ __handle_secondary_request(void *param)
(const struct eal_dev_mp_req *)msg->param;
struct eal_dev_mp_req tmp_req;
struct rte_devargs *da;
- struct rte_device *dev;
+ struct rte_device *dev = NULL;
struct rte_bus *bus;
int ret = 0;
@@ -168,7 +168,15 @@ __handle_secondary_request(void *param)
if (req->t == EAL_DEV_REQ_TYPE_ATTACH) {
tmp_req.t = EAL_DEV_REQ_TYPE_ATTACH_ROLLBACK;
eal_dev_hotplug_request_to_secondary(&tmp_req);
- local_dev_remove(dev);
+ if (dev == NULL) {
+ /* device was already attached at the time we got the
+ * request, don't detach it now.
+ */
+ RTE_LOG(WARNING, EAL,
+ "Devices in secondary may not sync with
primary\n");
+ } else {
+ local_dev_remove(dev);
+ }
} else {
tmp_req.t = EAL_DEV_REQ_TYPE_DETACH_ROLLBACK;
eal_dev_hotplug_request_to_secondary(&tmp_req);
--
2.17.1
