kernel/linux.git/drivers/net/hyperv, branch v4.14.85

hv_netvsc: fix schedule in RCU context

2018-10-18T07:16:22+00:00

[ Upstream commit 018349d70f28a78d5343b3660cb66e1667005f8a ] When netvsc device is removed it can call reschedule in RCU context. This happens because canceling the subchannel setup work could (in theory) cause a reschedule when manipulating the timer. To reproduce, run with lockdep enabled kernel and unbind a network device from hv_netvsc (via sysfs). [ 160.682011] WARNING: suspicious RCU usage [ 160.707466] 4.19.0-rc3-uio+ #2 Not tainted [ 160.709937] ----------------------------- [ 160.712352] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section! [ 160.723691] [ 160.723691] other info that might help us debug this: [ 160.723691] [ 160.730955] [ 160.730955] rcu_scheduler_active = 2, debug_locks = 1 [ 160.762813] 5 locks held by rebind-eth.sh/1812: [ 160.766851] #0: 000000008befa37a (sb_writers#6){.+.+}, at: vfs_write+0x184/0x1b0 [ 160.773416] #1: 00000000b097f236 (&of->mutex){+.+.}, at: kernfs_fop_write+0xe2/0x1a0 [ 160.783766] #2: 0000000041ee6889 (kn->count#3){++++}, at: kernfs_fop_write+0xeb/0x1a0 [ 160.787465] #3: 0000000056d92a74 (&dev->mutex){....}, at: device_release_driver_internal+0x39/0x250 [ 160.816987] #4: 0000000030f6031e (rcu_read_lock){....}, at: netvsc_remove+0x1e/0x250 [hv_netvsc] [ 160.828629] [ 160.828629] stack backtrace: [ 160.831966] CPU: 1 PID: 1812 Comm: rebind-eth.sh Not tainted 4.19.0-rc3-uio+ #2 [ 160.832952] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012 [ 160.832952] Call Trace: [ 160.832952] dump_stack+0x85/0xcb [ 160.832952] ___might_sleep+0x1a3/0x240 [ 160.832952] __flush_work+0x57/0x2e0 [ 160.832952] ? __mutex_lock+0x83/0x990 [ 160.832952] ? __kernfs_remove+0x24f/0x2e0 [ 160.832952] ? __kernfs_remove+0x1b2/0x2e0 [ 160.832952] ? mark_held_locks+0x50/0x80 [ 160.832952] ? get_work_pool+0x90/0x90 [ 160.832952] __cancel_work_timer+0x13c/0x1e0 [ 160.832952] ? netvsc_remove+0x1e/0x250 [hv_netvsc] [ 160.832952] ? __lock_is_held+0x55/0x90 [ 160.832952] netvsc_remove+0x9a/0x250 [hv_netvsc] [ 160.832952] vmbus_remove+0x26/0x30 [ 160.832952] device_release_driver_internal+0x18a/0x250 [ 160.832952] unbind_store+0xb4/0x180 [ 160.832952] kernfs_fop_write+0x113/0x1a0 [ 160.832952] __vfs_write+0x36/0x1a0 [ 160.832952] ? rcu_read_lock_sched_held+0x6b/0x80 [ 160.832952] ? rcu_sync_lockdep_assert+0x2e/0x60 [ 160.832952] ? __sb_start_write+0x141/0x1a0 [ 160.832952] ? vfs_write+0x184/0x1b0 [ 160.832952] vfs_write+0xbe/0x1b0 [ 160.832952] ksys_write+0x55/0xc0 [ 160.832952] do_syscall_64+0x60/0x1b0 [ 160.832952] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 160.832952] RIP: 0033:0x7fe48f4c8154 Resolve this by getting RTNL earlier. This is safe because the subchannel work queue does trylock on RTNL and will detect the race. Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic") Signed-off-by: Stephen Hemminger Reviewed-by: Haiyang Zhang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

hv/netvsc: Fix NULL dereference at single queue mode fallback

2018-09-26T06:37:58+00:00

commit b19b46346f483ae055fa027cb2d5c2ca91484b91 upstream. The recent commit 916c5e1413be ("hv/netvsc: fix handling of fallback to single queue mode") tried to fix the fallback behavior to a single queue mode, but it changed the function to return zero incorrectly, while the function should return an object pointer. Eventually this leads to a NULL dereference at the callers that expect non-NULL value. Fix it by returning the proper net_device object. Fixes: 916c5e1413be ("hv/netvsc: fix handling of fallback to single queue mode") Signed-off-by: Takashi Iwai Reviewed-by: Stephen Hemminger Signed-off-by: David S. Miller Cc: Alakesh Haloi Signed-off-by: Greg Kroah-Hartman

hv_netvsc: Fix a deadlock by getting rtnl lock earlier in netvsc_probe()

2018-09-15T07:45:26+00:00

[ Upstream commit e04e7a7bbd4bbabef4e1a58367e5fc9b2edc3b10 ] This patch fixes the race between netvsc_probe() and rndis_set_subchannel(), which can cause a deadlock. These are the related 3 paths which show the deadlock: path #1: Workqueue: hv_vmbus_con vmbus_onmessage_work [hv_vmbus] Call Trace: schedule schedule_preempt_disabled __mutex_lock __device_attach bus_probe_device device_add vmbus_device_register vmbus_onoffer vmbus_onmessage_work process_one_work worker_thread kthread ret_from_fork path #2: schedule schedule_preempt_disabled __mutex_lock netvsc_probe vmbus_probe really_probe __driver_attach bus_for_each_dev driver_attach_async async_run_entry_fn process_one_work worker_thread kthread ret_from_fork path #3: Workqueue: events netvsc_subchan_work [hv_netvsc] Call Trace: schedule rndis_set_subchannel netvsc_subchan_work process_one_work worker_thread kthread ret_from_fork Before path #1 finishes, path #2 can start to run, because just before the "bus_probe_device(dev);" in device_add() in path #1, there is a line "object_uevent(&dev->kobj, KOBJ_ADD);", so systemd-udevd can immediately try to load hv_netvsc and hence path #2 can start to run. Next, path #2 offloads the subchannal's initialization to a workqueue, i.e. path #3, so we can end up in a deadlock situation like this: Path #2 gets the device lock, and is trying to get the rtnl lock; Path #3 gets the rtnl lock and is waiting for all the subchannel messages to be processed; Path #1 is trying to get the device lock, but since #2 is not releasing the device lock, path #1 has to sleep; since the VMBus messages are processed one by one, this means the sub-channel messages can't be procedded, so #3 has to sleep with the rtnl lock held, and finally #2 has to sleep... Now all the 3 paths are sleeping and we hit the deadlock. With the patch, we can make sure #2 gets both the device lock and the rtnl lock together, gets its job done, and releases the locks, so #1 and #3 will not be blocked for ever. Fixes: 8195b1396ec8 ("hv_netvsc: fix deadlock on hotplug") Signed-off-by: Dexuan Cui Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hv_netvsc: ignore devices that are not PCI

2018-09-15T07:45:26+00:00

[ Upstream commit b93c1b5ac8643cc08bb74fa8ae21d6c63dfcb23d ] Registering another device with same MAC address (such as TAP, VPN or DPDK KNI) will confuse the VF autobinding logic. Restrict the search to only run if the device is known to be a PCI attached VF. Fixes: e8ff40d4bff1 ("hv_netvsc: improve VF device matching") Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hv/netvsc: fix handling of fallback to single queue mode

2018-08-24T11:09:18+00:00

[ Upstream commit 916c5e1413be058d1c1f6e502db350df890730ce ] The netvsc device may need to fallback to running in single queue mode if host side only wants to support single queue. Recent change for handling mtu broke this in setup logic. Reported-by: Dan Carpenter Fixes: 3ffe64f1a641 ("hv_netvsc: split sub-channel setup into async and sync") Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

hv_netvsc: fix network namespace issues with VF support

2018-08-03T05:50:22+00:00

[ Upstream commit 7bf7bb37f16a80465ee3bd7c6c966f96f5a075a6 ] When finding the parent netvsc device, the search needs to be across all netvsc device instances (independent of network namespace). Find parent device of VF using upper_dev_get routine which searches only adjacent list. Fixes: e8ff40d4bff1 ("hv_netvsc: improve VF device matching") Signed-off-by: Stephen Hemminger netns aware byref Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

hv_netvsc: Fix napi reschedule while receive completion is busy

2018-07-25T09:25:10+00:00

[ Upstream commit 6b81b193b83e87da1ea13217d684b54fccf8ee8a ] If out ring is full temporarily and receive completion cannot go out, we may still need to reschedule napi if certain conditions are met. Otherwise the napi poll might be stopped forever, and cause network disconnect. Fixes: 7426b1a51803 ("netvsc: optimize receive completions") Signed-off-by: Stephen Hemminger Signed-off-by: Haiyang Zhang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hv_netvsc: split sub-channel setup into async and sync

2018-07-22T12:28:43+00:00

[ Upstream commit 3ffe64f1a641b80a82d9ef4efa7a05ce69049871 ] When doing device hotplug the sub channel must be async to avoid deadlock issues because device is discovered in softirq context. When doing changes to MTU and number of channels, the setup must be synchronous to avoid races such as when MTU and device settings are done in a single ip command. Reported-by: Thomas Walker Fixes: 8195b1396ec8 ("hv_netvsc: fix deadlock on hotplug") Fixes: 732e49850c5e ("netvsc: fix race on sub channel creation") Signed-off-by: Stephen Hemminger Signed-off-by: Haiyang Zhang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hv_netvsc: Fix a network regression after ifdown/ifup

2018-06-26T00:06:28+00:00

[ Upstream commit 52acf73b6e9a6962045feb2ba5a8921da2201915 ] Recently people reported the NIC stops working after "ifdown eth0; ifup eth0". It turns out in this case the TX queues are not enabled, after the refactoring of the common detach logic: when the NIC has sub-channels, usually we enable all the TX queues after all sub-channels are set up: see rndis_set_subchannel() -> netif_device_attach(), but in the case of "ifdown eth0; ifup eth0" where the number of channels doesn't change, we also must make sure the TX queues are enabled. The patch fixes the regression. Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic") Signed-off-by: Dexuan Cui Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hv_netvsc: enable multicast if necessary

2018-05-30T05:52:21+00:00

[ Upstream commit f03dbb06dc380274e351ca4b1ee1587ed4529e62 ] My recent change to netvsc drive in how receive flags are handled broke multicast. The Hyper-v/Azure virtual interface there is not a multicast filter list, filtering is only all or none. The driver must enable all multicast if any multicast address is present. Fixes: 009f766ca238 ("hv_netvsc: filter multicast/broadcast") Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman