Re: rtnl_lock deadlock with tg3 driver
From: Baptiste Covolato <hidden>
Date: 2020-08-31 19:20:47
On Sun, Aug 30, 2020 at 9:58 PM Michael Chan [off-list ref] wrote:
On Fri, Aug 28, 2020 at 5:40 PM Baptiste Covolato [off-list ref] wrote:quoted
Hi David, Michael, I am contacting you because I'm experiencing an issue that seems to be awfully close to what David attempted to fix related to the tg3 driver infinite sleep while holding rtnl_lock (https://lkml.org/lkml/2020/6/15/1122).David's remaining issue was tg3_reset_task() returning failure due to some hardware error. This would leave the driver in a limbo state with netif_running() still true, but NAPI not enabled. This can easily lead to a soft lockup with rtnl held when it tries to disable NAPI again. I think the proper fix is to close the device when tg3_reset_task() fails to bring it to a consistent state. I haven't heard back from David in a while, so I will propose a patch to do this in the next day. Let's see if this patch will also work for you. Thanks.
Thanks Michael. Looking forward to trying this patch out. -- Baptiste Covolato