== DF-2374 hook dispatch vs deregister race (ACHARNESS #3, 90s) ==
ACSIM: op: hook_reg
ACSIM: DF-2374 hook cmd 0xdf740001 registered (fn=0xffffffff806....)
ACSIM: op: hook_churn_start
ACSIM: DF-2374 churn kthread started: dereg+canary+rereg loop
hook_racer: 1607354 ioctls (0 dispatched-ok-counted, all hook_fn calls) in 90s
ACSIM: DF-2374 churn stopped: calls=1607354 regs=5175 deregs=5175
RESULT: no panic / no canary jump in 5175 free+canary windows -- race not closed
(same result in an earlier 45s attempt; window: acpi.c:3421 unlock -> :3426 hp->fn)