netdev - Re: [PATCH net v2 2/2] net: ks8851: Handle softirqs at the end of IRQ thread to fix hang

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <a8e28385-5b92-4149-be0c-cfce6394fbc2@denx.de>
Date: Fri, 12 Apr 2024 13:29:04 +0200
From: Marek Vasut <marex@...x.de>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>,
 Uwe Kleine-König <u.kleine-koenig@...gutronix.de>,
 Dmitry Torokhov <dmitry.torokhov@...il.com>,
 Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
 Mark Brown <broonie@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
 Ratheesh Kannoth <rkannoth@...vell.com>,
 Ronald Wahl <ronald.wahl@...itan.com>, Simon Horman <horms@...nel.org>
Subject: Re: [PATCH net v2 2/2] net: ks8851: Handle softirqs at the end of IRQ
 thread to fix hang

On 4/8/24 4:52 PM, Andy Shevchenko wrote:
> On Fri, Apr 05, 2024 at 10:30:40PM +0200, Marek Vasut wrote:
>> The ks8851_irq() thread may call ks8851_rx_pkts() in case there are
>> any packets in the MAC FIFO, which calls netif_rx(). This netif_rx()
>> implementation is guarded by local_bh_disable() and local_bh_enable().
>> The local_bh_enable() may call do_softirq() to run softirqs in case
>> any are pending. One of the softirqs is net_rx_action, which ultimately
>> reaches the driver .start_xmit callback. If that happens, the system
>> hangs. The entire call chain is below:
>>
>> ks8851_start_xmit_par from netdev_start_xmit
>> netdev_start_xmit from dev_hard_start_xmit
>> dev_hard_start_xmit from sch_direct_xmit
>> sch_direct_xmit from __dev_queue_xmit
>> __dev_queue_xmit from __neigh_update
>> __neigh_update from neigh_update
>> neigh_update from arp_process.constprop.0
>> arp_process.constprop.0 from __netif_receive_skb_one_core
>> __netif_receive_skb_one_core from process_backlog
>> process_backlog from __napi_poll.constprop.0
>> __napi_poll.constprop.0 from net_rx_action
>> net_rx_action from __do_softirq
>> __do_softirq from call_with_stack
>> call_with_stack from do_softirq
>> do_softirq from __local_bh_enable_ip
>> __local_bh_enable_ip from netif_rx
>> netif_rx from ks8851_irq
>> ks8851_irq from irq_thread_fn
> 
>> irq_thread_fn from irq_thread
>> irq_thread from kthread
>> kthread from ret_from_fork
> 
> These lines are unneeded (in case you need a new version, you can drop them).

I just got back and going through a mountain of email, I see Jakub 
already picked the V2, so, noted for next time. Thank you !