| Message ID | 20201126125520.72912-1-stf_xl@wp.pl (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 807982017730cfe853fce49ba26d453e31c84898 |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | [5.10] mt76: usb: fix crash on device removal | expand |
On 2020-11-26 13:55, stf_xl@wp.pl wrote: > From: Stanislaw Gruszka <stf_xl@wp.pl> > > Currently 'while (q->queued > 0)' loop was removed from mt76u_stop_tx() > code. This causes crash on device removal as we try to cleanup empty > queue: > > [ 96.495571] kernel BUG at include/linux/skbuff.h:2297! > [ 96.498983] invalid opcode: 0000 [#1] SMP PTI > [ 96.501162] CPU: 3 PID: 27 Comm: kworker/3:0 Not tainted 5.10.0-rc5+ #11 > [ 96.502754] Hardware name: LENOVO 20DGS08H00/20DGS08H00, BIOS J5ET48WW (1.19 ) 08/27/2015 > [ 96.504378] Workqueue: usb_hub_wq hub_event > [ 96.505983] RIP: 0010:skb_pull+0x2d/0x30 > [ 96.507576] Code: 00 00 8b 47 70 39 c6 77 1e 29 f0 89 47 70 3b 47 74 72 17 48 8b 87 c8 00 00 00 89 f6 48 01 f0 48 89 87 c8 00 00 00 c3 31 c0 c3 <0f> 0b 90 0f 1f 44 00 00 53 48 89 fb 48 8b bf c8 00 00 00 8b 43 70 > [ 96.509296] RSP: 0018:ffffb11b801639b8 EFLAGS: 00010287 > [ 96.511038] RAX: 000000001c6939ed RBX: ffffb11b801639f8 RCX: 0000000000000000 > [ 96.512964] RDX: ffffb11b801639f8 RSI: 0000000000000018 RDI: ffff90c64e4fb800 > [ 96.514710] RBP: ffff90c654551ee0 R08: ffff90c652bce7a8 R09: ffffb11b80163728 > [ 96.516450] R10: 0000000000000001 R11: 0000000000000001 R12: ffff90c64e4fb800 > [ 96.519749] R13: 0000000000000010 R14: 0000000000000020 R15: ffff90c64e352ce8 > [ 96.523455] FS: 0000000000000000(0000) GS:ffff90c96eec0000(0000) knlGS:0000000000000000 > [ 96.527171] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 96.530900] CR2: 0000242556f18288 CR3: 0000000146a10002 CR4: 00000000003706e0 > [ 96.534678] Call Trace: > [ 96.538418] mt76x02u_tx_complete_skb+0x1f/0x50 [mt76x02_usb] > [ 96.542231] mt76_queue_tx_complete+0x23/0x50 [mt76] > [ 96.546028] mt76u_stop_tx.cold+0x71/0xa2 [mt76_usb] > [ 96.549797] mt76x0u_stop+0x2f/0x90 [mt76x0u] > [ 96.553638] drv_stop+0x33/0xd0 [mac80211] > [ 96.557449] ieee80211_do_stop+0x558/0x860 [mac80211] > [ 96.561262] ? dev_deactivate_many+0x298/0x2d0 > [ 96.565101] ieee80211_stop+0x16/0x20 [mac80211] > > Fix that by adding while loop again. We need loop, not just single > check, to clean all pending entries. > > Additionally move mt76_worker_disable/enable after !mt76_has_tx_pending() > as we want to tx_worker to run to process tx queues, while we wait for > exactly that. > > I was a bit worried about accessing q->queued without lock, but > mt76_worker_disable() -> kthread_park() should assure this value will > be seen updated on other cpus. > > Fixes: fe5b5ab52e9d ("mt76: unify queue tx cleanup code") > Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl> Acked-by: Felix Fietkau <nbd@nbd.name> Thanks, - Felix
stf_xl@wp.pl wrote: > From: Stanislaw Gruszka <stf_xl@wp.pl> > > Currently 'while (q->queued > 0)' loop was removed from mt76u_stop_tx() > code. This causes crash on device removal as we try to cleanup empty > queue: > > [ 96.495571] kernel BUG at include/linux/skbuff.h:2297! > [ 96.498983] invalid opcode: 0000 [#1] SMP PTI > [ 96.501162] CPU: 3 PID: 27 Comm: kworker/3:0 Not tainted 5.10.0-rc5+ #11 > [ 96.502754] Hardware name: LENOVO 20DGS08H00/20DGS08H00, BIOS J5ET48WW (1.19 ) 08/27/2015 > [ 96.504378] Workqueue: usb_hub_wq hub_event > [ 96.505983] RIP: 0010:skb_pull+0x2d/0x30 > [ 96.507576] Code: 00 00 8b 47 70 39 c6 77 1e 29 f0 89 47 70 3b 47 74 72 17 48 8b 87 c8 00 00 00 89 f6 48 01 f0 48 89 87 c8 00 00 00 c3 31 c0 c3 <0f> 0b 90 0f 1f 44 00 00 53 48 89 fb 48 8b bf c8 00 00 00 8b 43 70 > [ 96.509296] RSP: 0018:ffffb11b801639b8 EFLAGS: 00010287 > [ 96.511038] RAX: 000000001c6939ed RBX: ffffb11b801639f8 RCX: 0000000000000000 > [ 96.512964] RDX: ffffb11b801639f8 RSI: 0000000000000018 RDI: ffff90c64e4fb800 > [ 96.514710] RBP: ffff90c654551ee0 R08: ffff90c652bce7a8 R09: ffffb11b80163728 > [ 96.516450] R10: 0000000000000001 R11: 0000000000000001 R12: ffff90c64e4fb800 > [ 96.519749] R13: 0000000000000010 R14: 0000000000000020 R15: ffff90c64e352ce8 > [ 96.523455] FS: 0000000000000000(0000) GS:ffff90c96eec0000(0000) knlGS:0000000000000000 > [ 96.527171] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 96.530900] CR2: 0000242556f18288 CR3: 0000000146a10002 CR4: 00000000003706e0 > [ 96.534678] Call Trace: > [ 96.538418] mt76x02u_tx_complete_skb+0x1f/0x50 [mt76x02_usb] > [ 96.542231] mt76_queue_tx_complete+0x23/0x50 [mt76] > [ 96.546028] mt76u_stop_tx.cold+0x71/0xa2 [mt76_usb] > [ 96.549797] mt76x0u_stop+0x2f/0x90 [mt76x0u] > [ 96.553638] drv_stop+0x33/0xd0 [mac80211] > [ 96.557449] ieee80211_do_stop+0x558/0x860 [mac80211] > [ 96.561262] ? dev_deactivate_many+0x298/0x2d0 > [ 96.565101] ieee80211_stop+0x16/0x20 [mac80211] > > Fix that by adding while loop again. We need loop, not just single > check, to clean all pending entries. > > Additionally move mt76_worker_disable/enable after !mt76_has_tx_pending() > as we want to tx_worker to run to process tx queues, while we wait for > exactly that. > > I was a bit worried about accessing q->queued without lock, but > mt76_worker_disable() -> kthread_park() should assure this value will > be seen updated on other cpus. > > Fixes: fe5b5ab52e9d ("mt76: unify queue tx cleanup code") > Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl> > Acked-by: Felix Fietkau <nbd@nbd.name> Patch applied to wireless-drivers.git, thanks. 807982017730 mt76: usb: fix crash on device removal
diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c index 7d3f0a2e5fa0..f1ae9ff835b2 100644 --- a/drivers/net/wireless/mediatek/mt76/usb.c +++ b/drivers/net/wireless/mediatek/mt76/usb.c @@ -1020,8 +1020,6 @@ void mt76u_stop_tx(struct mt76_dev *dev) { int ret; - mt76_worker_disable(&dev->tx_worker); - ret = wait_event_timeout(dev->tx_wait, !mt76_has_tx_pending(&dev->phy), HZ / 5); if (!ret) { @@ -1040,6 +1038,8 @@ void mt76u_stop_tx(struct mt76_dev *dev) usb_kill_urb(q->entry[j].urb); } + mt76_worker_disable(&dev->tx_worker); + /* On device removal we maight queue skb's, but mt76u_tx_kick() * will fail to submit urb, cleanup those skb's manually. */ @@ -1048,18 +1048,19 @@ void mt76u_stop_tx(struct mt76_dev *dev) if (!q) continue; - entry = q->entry[q->tail]; - q->entry[q->tail].done = false; - - mt76_queue_tx_complete(dev, q, &entry); + while (q->queued > 0) { + entry = q->entry[q->tail]; + q->entry[q->tail].done = false; + mt76_queue_tx_complete(dev, q, &entry); + } } + + mt76_worker_enable(&dev->tx_worker); } cancel_work_sync(&dev->usb.stat_work); clear_bit(MT76_READING_STATS, &dev->phy.state); - mt76_worker_enable(&dev->tx_worker); - mt76_tx_status_check(dev, NULL, true); } EXPORT_SYMBOL_GPL(mt76u_stop_tx);