Re: BUG: unable to handle kernel paging request from pty_write [was: Linux 4.4.2]

On Thu, 25 Feb 2016 11:09:35 -0800
Linus Torvalds [off-list ref] wrote:

Jiri, were you messing around with tracing when this happened? Or
maybe shutting down CPU's? There was a RCU locking problem with CPU
shutdown, maybe this is one of the symptoms. The fix for that is
recent, and not in 4.4.2.

Adding Steven Rostedt to the cc. Steven, does that look like a possible case?

Possible: yes. Likely: no

The recent fix would require shutting down a CPU at the same time as a
tracepoint is enabled or disabled. Rather difficult to hit, but easier
on a virtual machine. If Jiri was not enabling/disabling tracepoints or
shutting down CPUs, then it would not be the bug.

But as the comm of the bug is gdb and this running on a virtual
machine, I think the bug may be elsewhere. Corrupt stack possibly?

-- Steve