This is related to CONFIG_DEBUG_OBJECTS but may be relevant for other debug configs as well. We should use lib/stackdepot.c (CONFIG_STACKDEPOT) in more debugging facilities to memorize full stack traces. stackdepot maps a full stack trace to an u32 (i.e. smaller than memorizing a single PC).
In particular come up in the context of:
which contains just:
------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint:
and then Thomas says:
"One of the cleaned up devices has left an active timer which belongs to a
delayed work. That's all I can decode out of that splat. :("
Presumably having a full stack for the timer allocation would make this actionable.