linux/drivers/net/hyperv, branch v4.19

hv_netvsc: pair VF based on serial number

2018-09-17T14:59:41Z

Matching network device based on MAC address is problematic since a non VF network device can be creted with a duplicate MAC address causing confusion and problems. The VMBus API does provide a serial number that is a better matching method. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

hv_netvsc: fix schedule in RCU context

2018-09-13T17:30:26Z

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

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

2018-09-01T06:07:54Z

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

hv_netvsc: ignore devices that are not PCI

2018-08-21T19:02:11Z

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

Merge tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2018-08-18T18:04:51Z

Pull char/misc driver updates from Greg KH: "Here is the bit set of char/misc drivers for 4.19-rc1 There is a lot here, much more than normal, seems like everyone is writing new driver subsystems these days... Anyway, major things here are: - new FSI driver subsystem, yet-another-powerpc low-level hardware bus - gnss, finally an in-kernel GPS subsystem to try to tame all of the crazy out-of-tree drivers that have been floating around for years, combined with some really hacky userspace implementations. This is only for GNSS receivers, but you have to start somewhere, and this is great to see. Other than that, there are new slimbus drivers, new coresight drivers, new fpga drivers, and loads of DT bindings for all of these and existing drivers. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits) android: binder: Rate-limit debug and userspace triggered err msgs fsi: sbefifo: Bump max command length fsi: scom: Fix NULL dereference misc: mic: SCIF Fix scif_get_new_port() error handling misc: cxl: changed asterisk position genwqe: card_base: Use true and false for boolean values misc: eeprom: assignment outside the if statement uio: potential double frees if __uio_register_device() fails eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency misc: ti-st: Fix memory leak in the error path of probe() android: binder: Show extra_buffers_size in trace firmware: vpd: Fix section enabled flag on vpd_section_destroy platform: goldfish: Retire pdev_bus goldfish: Use dedicated macros instead of manual bit shifting goldfish: Add missing includes to goldfish.h mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux dt-bindings: mux: add adi,adgs1408 Drivers: hv: vmbus: Cleanup synic memory free path Drivers: hv: vmbus: Remove use of slow_virt_to_phys() Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind() ...

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

2018-08-14T17:24:12Z

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

hv_netvsc: Add per-cpu ethtool stats for netvsc

2018-07-30T19:35:04Z

This patch implements following ethtool stats fields for netvsc: cpu_tx/rx_packets/bytes cpu_vf_tx/rx_packets/bytes Corresponding per-cpu counters already exist in current code. Exposing these counters will help troubleshooting performance issues. for_each_present_cpu() was used instead of for_each_possible_cpu(). for_each_possible_cpu() would create very long and useless output. It is still being used for internal buffer, but not for ethtool output. There could be an overflow if cpu was added between ethtool call netvsc_get_sset_count() and netvsc_get_ethtool_stats() and netvsc_get_strings(). (still safe if cpu was removed) ethtool makes these three function calls separately. As long as we use ethtool, I can't see any clean solution. Currently and in foreseeable short term, Hyper-V doesn't support cpu hot-plug. Plus, ethtool is for admin use. Unlikely the admin would perform such combo operations. Changes in v2: - Remove cpp style comment - Resubmit after freeze Changes in v3: - Reimplemented with kvmalloc instead of alloc_percpu Changes in v4: - Fixed inconsistent array size - Use kvmalloc_array instead of kvmalloc Signed-off-by: Yidong Ren Reviewed-by: Stephen Hemminger Signed-off-by: David S. Miller

Merge ra.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux

2018-07-21T04:17:12Z

All conflicts were trivial overlapping changes, so reasonably easy to resolve. Signed-off-by: David S. Miller

hv_netvsc: Fix napi reschedule while receive completion is busy

2018-07-18T22:23:30Z

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

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

2018-07-16T21:01:10Z

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