On 30/09/2022 15:19, Jakub Kicinski wrote:

On Fri, 30 Sep 2022 10:03:01 +0100 Edward Cree wrote:

quoted

It has one (do_trace_netlink_extack()), but sadly that won't play
 so well with formatted extacks since AIUI trace needs a constant
 string (I'm just giving it the format string in my prototype).
But yeah it's better than nothing.

We can add a new one which copies the data. Presumably we'd have a "set
an extack msg which needs to be freed" helper were we could place it?
It'd mean we cut off at a static length but good enough, I say.

Hmm, seems I was wrong about the tracepoint, the machinery already
 handles a dynamic string just fine.
I should have an RFC patch ready in a few days.

-ed