Re: [PATCH] x86/debug: Handle warnings before the notifier chain

[Alexander Shishkin]

Peter Zijlstra <peterz@xxxxxxxxxxxxx> writes:

> On Mon, Jul 24, 2017 at 01:04:28PM +0300, Alexander Shishkin wrote:
>> Commit
>> 
>>   9a93848fe787 ("x86/debug: Implement __WARN() using UD0")
>> 
>> turned warnings into UD0, but the fixup code only runs after the
>> notify_die() chain. This is a problem, in particular, with kgdb,
>> which kicks in as if it was a BUG().
>> 
>> Fix this by running the fixup code before the notifier chain in
>> the invalid op handler path.
>
> So arguable it might be nice to have kgdb trap on a WARN, but it
> treating it as a BUG is obviously undesirable.
>
> Jason, what would you want kgdb to do here?

Ping.