scripts/system-tests/run-kprobe-fuzzing.py

   1 # Copyright (C) 2018 - Francis Deslauriers <francis.deslauriers@efficios.com>
   2 #
   3 # This program is free software: you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation, either version 3 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 import datetime
  17 import gzip
  18 import os
  19 import pprint
  20 import subprocess
  21 import sys
  22
  23 NB_KPROBES_PER_ITER=500
  24 NB_KPROBES_PER_ROUND=20000
  25
  26 def load_instr_points(instr_points_archive):
  27     print('Reading instrumentation points from \'{}\'.'.format(instr_points_archive), end='')
  28     sys.stdout.flush()
  29
  30     with gzip.open(instr_points_archive, 'r') as f:
  31         data = f.read()
  32     print(' Done.')
  33
  34     return [x.decode('utf-8') for x in data.split()]
  35
  36 def enable_kprobe_events(instr_points):
  37     print('Enabling events from {} to {}...'.format(instr_points[0], instr_points[-1]), end='')
  38     sys.stdout.flush()
  39
  40     # Use os module directly, because this is a sysfs file and seeking inside
  41     # the file is not supported. The python open() function with the append
  42     # ('a') flag uses lseek(, SEEK_END) to move the write pointer to the end.
  43     fd = os.open('/sys/kernel/debug/tracing/kprobe_events', os.O_WRONLY|os.O_CREAT|os.O_APPEND)
  44     for i, point in enumerate(instr_points):
  45
  46         kprobe_cmd = 'r:event_{} {}\n'.format(i, point).encode('utf-8')
  47         try:
  48             os.write(fd, kprobe_cmd)
  49         except OSError:
  50             continue
  51     os.close(fd)
  52     print(' Done.')
  53
  54 def set_kprobe_tracing_state(state):
  55     if state not in (0 ,1):
  56         raise ValueError
  57
  58     try:
  59         with open('/sys/kernel/debug/tracing/events/kprobes/enable', 'w') as enable_kprobe_file:
  60             enable_kprobe_file.write('{}\n'.format(state))
  61     except IOError:
  62         print('kprobes/enable file does not exist')
  63
  64     if state == 0:
  65         # Clear the content of the trace.
  66         open('/sys/kernel/debug/tracing/trace', 'w').close()
  67         # Clear all the events.
  68         open('/sys/kernel/debug/tracing/kprobe_events', 'w').close()
  69
  70 def run_workload():
  71     print('Running workload...', end='')
  72     sys.stdout.flush()
  73     workload = ['stress', '--cpu', '2', '--io', '4', '--vm', '2',
  74                 '--vm-bytes', '128M', '--hdd', '3', '--timeout', '3s']
  75     try:
  76         with open(os.devnull) as devnull:
  77             subprocess.call(workload, stdout=devnull, stderr=devnull)
  78     except OSError as e:
  79         print("Workload execution failed:", e, file=sys.stderr)
  80         pprint.pprint(workload)
  81
  82     print(' Done.')
  83
  84 def mount_tracingfs():
  85     with open(os.devnull) as devnull:
  86         subprocess.call(['mount', '-t', 'debugfs', 'nodev', '/sys/kernel/debug/'],
  87                 stdout=devnull, stderr=devnull)
  88
  89 def print_dashed_line():
  90     print('-'*100)
  91
  92 def main():
  93     assert(len(sys.argv) == 3)
  94
  95     instr_point_archive = sys.argv[1]
  96     round_nb = int(sys.argv[2])
  97     # Load instrumentation points to disk and attach it to lava test run.
  98     instrumentation_points = load_instr_points(instr_point_archive)
  99
 100     # We are past the end of the instrumentation point list.
 101     if len(instrumentation_points)/NB_KPROBES_PER_ROUND <= round_nb:
 102         print('No instrumentation point for round {}.'.format(round_nb))
 103         return
 104
 105     mount_tracingfs()
 106
 107     # Loop over the list by enabling ranges of NB_KPROBES_PER_ITER kprobes.
 108     for i in range(int(NB_KPROBES_PER_ROUND/NB_KPROBES_PER_ITER)):
 109         print_dashed_line()
 110         lower_bound = (round_nb * NB_KPROBES_PER_ROUND) + (i * NB_KPROBES_PER_ITER)
 111         upper_bound = lower_bound + NB_KPROBES_PER_ITER
 112         print('Time now: {}, {} to {}'.format(datetime.datetime.now(), lower_bound , upper_bound))
 113         enable_kprobe_events(instrumentation_points[lower_bound:upper_bound])
 114         set_kprobe_tracing_state(1)
 115         run_workload()
 116         print('\n')
 117         set_kprobe_tracing_state(0)
 118
 119 if __name__ == "__main__":
 120     main()