Re: [uml-devel] uml-patch-2.4.18-24

[Roger B. <ro...@ro...>]

> Do you have CONFIG_PT_PROXY enabled?  If so, turn it off, and UML should start
> exiting on panic.
> 
> The reason for the dependency is that if it panics with CONFIG_PT_PROXY on,
> even if there's no debugger on it, you can start one and get a backtrace.

I'd like to make a case for changing this behaviour.

By default I think UML should always exit on panic.  The reason is that it
will panic if you make simple errors such as mispelling ubd filenames,
not having an init, giving poor command line options etc.  For the novice
or non-developer user, it is then quite difficult to figure out how to
get out of this.  Even my command history is full of 'killall linux'
(and hope I never run two instances of it).

If a panic does happen to a developer type, they can merely reproduce it
under the right debug environment.

The only time you 'lose' is if something is unrepeatable, which usually
isn't of much use anyway.

You can get the best of both worlds by having a command line switch that 
sets panic behaviour.  For example, the default would be 'onpanic=exit'
and people who care can set it to 'onpanic=debug' or coredump or whatever.

Roger