tools/exitsnoop: Remove ctypes cast operation

tools/exitsnoop.py

@@ -3,7 +3,6 @@
 from __future__ import print_function
 
 import argparse
-import ctypes as ct
 import os
 import platform
 import re
@@ -78,22 +77,6 @@ class Global():
  SIGNUM_TO_SIGNAME = dict((v, re.sub("^SIG", "", k))
  for k,v in signal.__dict__.items() if re.match("^SIG[A-Z]+$", k))
 
-
-class Data(ct.Structure):
- """Event data matching struct data_t in _embedded_c()."""
- _TASK_COMM_LEN = 16 # linux/sched.h
- _pack_ = 1
- _fields_ = [
- ("start_time", ct.c_ulonglong), # task->start_time, see --timespec arg
- ("exit_time", ct.c_ulonglong), # bpf_ktime_get_ns()
- ("pid", ct.c_uint), # task->tgid, thread group id == sys_getpid()
- ("tid", ct.c_uint), # task->pid, thread id == sys_gettid()
- ("ppid", ct.c_uint),# task->parent->tgid, notified of exit
- ("exit_code", ct.c_int),
- ("sig_info", ct.c_uint),
- ("task", ct.c_char * _TASK_COMM_LEN)
- ]
-
 def _embedded_c(args):
  """Generate C program for sched_process_exit tracepoint in kernel/exit.c."""
  c = """
@@ -112,7 +95,6 @@ def _embedded_c(args):
  char task[TASK_COMM_LEN];
  } __attribute__((packed));
 
- BPF_STATIC_ASSERT(sizeof(struct data_t) == CTYPES_SIZEOF_DATA);
  BPF_PERF_OUTPUT(events);
 
  TRACEPOINT_PROBE(sched, sched_process_exit)
@@ -154,7 +136,6 @@ def _embedded_c(args):
  code_substitutions = [
  ('EBPF_COMMENT', '' if not Global.args.ebpf else _ebpf_comment()),
  ("BPF_STATIC_ASSERT_DEF", bpf_static_assert_def),
- ("CTYPES_SIZEOF_DATA", str(ct.sizeof(Data))),
  ('FILTER_PID', filter_pid),
  ('FILTER_EXIT_CODE', '0' if not Global.args.failed else 'task->exit_code == 0'),
  ('PROCESS_START_TIME_NS', 'task->start_time' if not Global.args.timespec else
@@ -182,9 +163,12 @@ def _print_header():
  print("%-16s %-6s %-6s %-6s %-7s %-10s" %
  ("PCOMM", "PID", "PPID", "TID", "AGE(s)", "EXIT_CODE"))
 
+buffer = None
+
 def _print_event(cpu, data, size): # callback
  """Print the exit event."""
- e = ct.cast(data, ct.POINTER(Data)).contents
+ global buffer
+ e = buffer["events"].event(data)
  if Global.args.timestamp:
  now = datetime.utcnow() if Global.args.utc else datetime.now()
  print("%-13s" % (now.strftime("%H:%M:%S.%f")[:-3]), end="")
@@ -271,6 +255,7 @@ def signum_to_signame(signum):
 # Script: invoked as a script
 # =============================
 def main():
+ global buffer
  try:
  rc, buffer = initialize()
  if rc: