netdev - Re: [PATCH net] virtio_net: move netdev_tx_reset

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACGkMEs3X8KH3zHLkT74COqHa6N9noKT8TaUj-KRLkaok4Pv_w@mail.gmail.com>
Date: Thu, 15 Aug 2024 14:03:26 +0800
From: Jason Wang <jasowang@...hat.com>
To: "Michael S. Tsirkin" <mst@...hat.com>
Cc: Jiri Pirko <jiri@...nulli.us>, virtualization@...ts.linux.dev, 
	xuanzhuo@...ux.alibaba.com, eperezma@...hat.com, davem@...emloft.net, 
	edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com, 
	netdev@...r.kernel.org, m.szyprowski@...sung.com
Subject: Re: [PATCH net] virtio_net: move netdev_tx_reset_queue() call before
 RX napi enable

On Wed, Aug 14, 2024 at 8:29 PM Michael S. Tsirkin <mst@...hat.com> wrote:
>
> On Wed, Aug 14, 2024 at 02:25:00PM +0200, Jiri Pirko wrote:
> > From: Jiri Pirko <jiri@...dia.com>
> >
> > During suspend/resume the following BUG was hit:
> > ------------[ cut here ]------------
> > kernel BUG at lib/dynamic_queue_limits.c:99!
> > Internal error: Oops - BUG: 0 [#1] SMP ARM
> > Modules linked in: bluetooth ecdh_generic ecc libaes
> > CPU: 1 PID: 1282 Comm: rtcwake Not tainted
> > 6.10.0-rc3-00732-gc8bd1f7f3e61 #15240
> > Hardware name: Generic DT based system
> > PC is at dql_completed+0x270/0x2cc
> > LR is at __free_old_xmit+0x120/0x198
> > pc : [<c07ffa54>]    lr : [<c0c42bf4>]    psr: 80000013
> > ...
> > Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
> > Control: 10c5387d  Table: 43a4406a  DAC: 00000051
> > ...
> > Process rtcwake (pid: 1282, stack limit = 0xfbc21278)
> > Stack: (0xe0805e80 to 0xe0806000)
> > ...
> > Call trace:
> >   dql_completed from __free_old_xmit+0x120/0x198
> >   __free_old_xmit from free_old_xmit+0x44/0xe4
> >   free_old_xmit from virtnet_poll_tx+0x88/0x1b4
> >   virtnet_poll_tx from __napi_poll+0x2c/0x1d4
> >   __napi_poll from net_rx_action+0x140/0x2b4
> >   net_rx_action from handle_softirqs+0x11c/0x350
> >   handle_softirqs from call_with_stack+0x18/0x20
> >   call_with_stack from do_softirq+0x48/0x50
> >   do_softirq from __local_bh_enable_ip+0xa0/0xa4
> >   __local_bh_enable_ip from virtnet_open+0xd4/0x21c
> >   virtnet_open from virtnet_restore+0x94/0x120
> >   virtnet_restore from virtio_device_restore+0x110/0x1f4
> >   virtio_device_restore from dpm_run_callback+0x3c/0x100
> >   dpm_run_callback from device_resume+0x12c/0x2a8
> >   device_resume from dpm_resume+0x12c/0x1e0
> >   dpm_resume from dpm_resume_end+0xc/0x18
> >   dpm_resume_end from suspend_devices_and_enter+0x1f0/0x72c
> >   suspend_devices_and_enter from pm_suspend+0x270/0x2a0
> >   pm_suspend from state_store+0x68/0xc8
> >   state_store from kernfs_fop_write_iter+0x10c/0x1cc
> >   kernfs_fop_write_iter from vfs_write+0x2b0/0x3dc
> >   vfs_write from ksys_write+0x5c/0xd4
> >   ksys_write from ret_fast_syscall+0x0/0x54
> > Exception stack(0xe8bf1fa8 to 0xe8bf1ff0)
> > ...
> > ---[ end trace 0000000000000000 ]---
> >
> > After virtnet_napi_enable() is called, the following path is hit:
> >   __napi_poll()
> >     -> virtnet_poll()
> >       -> virtnet_poll_cleantx()
> >         -> netif_tx_wake_queue()
> >
> > That wakes the TX queue and allows skbs to be submitted and accounted by
> > BQL counters.
> >
> > Then netdev_tx_reset_queue() is called that resets BQL counters and
> > eventually leads to the BUG in dql_completed().
> >
> > Move virtnet_napi_tx_enable() what does BQL counters reset before RX
> > napi enable to avoid the issue.
> >
> > Reported-by: Marek Szyprowski <m.szyprowski@...sung.com>
> > Closes: https://lore.kernel.org/netdev/e632e378-d019-4de7-8f13-07c572ab37a9@samsung.com/
> > Fixes: c8bd1f7f3e61 ("virtio_net: add support for Byte Queue Limits")
> > Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>
> > Signed-off-by: Jiri Pirko <jiri@...dia.com>
>
> Acked-by: Michael S. Tsirkin <mst@...hat.com>

Acked-by: Jason Wang <jasowang@...hat.com>

Thanks