The problem seems to happen in this line of trace_event_ignore_this_pid():

pid_list = rcu_dereference_raw(tr->filtered_pids);

It seems it got inlined within trace_event_buffer_reserve()

There strangest thing I found so far is this:

crash> sym global_trace
ffffffffbcdb7e80 (d) global_trace
crash> list ftrace_trace_arrays
ffffffffbcdb7e70
ffffffffbcdb7e80

trace_array has size 7672, but ffffffffbcdb7e70 is only 16 bytes away from
ffffffffbcdb7e80.

Also this:

crash> struct trace_array.events -o global_trace
struct trace_array {
  [ffffffffbcdb9be0] struct list_head events;
}
crash> list -s trace_event_file.tr -o trace_event_file.list ffffffffbcdb9be0
ffffffffbcdb9be0
  tr = 0xffffffffbcdb7b20
ffff8ccb45cdfb00
  tr = 0xffffffffbcdb7e80
ffff8ccb45cdf580
  tr = 0xffffffffbcdb7e80
ffff8ccb45cdfe18
  tr = 0xffffffffbcdb7e80
...
  tr = 0xffffffffbcdb7e80

The first one 0xffffffffbcdb7b20 is only 864 bytes away from 0xffffffffbcdb7e80