lua: Do not try to detach buffers as kprobes

src/lua/bcc/bpf.lua

@@ -41,7 +41,8 @@ function Bpf.static.cleanup_probes()
   local function detach_all(probe_type, all_probes)
     for key, probe in pairs(all_probes) do
       libbcc.perf_reader_free(probe)
-      if type(key) == "string" then
+      -- skip bcc-specific kprobes
+      if not key:starts("bcc:") then
         local desc = string.format("-:%s/%s", probe_type, key)
         log.info("detaching %s", desc)
 

src/lua/bcc/table.lua

@@ -236,7 +236,7 @@ function PerfEventArray:initialize(bpf, map_id, map_fd, key_type, leaf_type)
 end
 
 local function _perf_id(id, cpu)
-  return string.format("perf_event_array:%d:%d", tonumber(id), cpu or 0)
+  return string.format("bcc:perf_event_array:%d:%d", tonumber(id), cpu or 0)
 end
 
 function PerfEventArray:_open_perf_buffer(cpu, callback, ctype)