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
  25 def load_instr_points(instr_points_archive):
  26     print('Reading instrumentation points from \'{}\'.'.format(instr_points_archive), end='')
  27     sys.stdout.flush()
  28
  29     with gzip.open(instr_points_archive, 'r') as f:
  30         data = f.read()
  31     print(' Done.')
  32
  33     return [x.decode('utf-8') for x in data.split()]
  34
  35 def enable_kprobe_events(instr_points):
  36     print('Enabling events...', end='')
  37     sys.stdout.flush()
  38
  39     # Use os module directly, because this is a sysfs file and seeking inside
  40     # the file is not supported. The python open() function with the append
  41     # ('a') flag uses lseek(, SEEK_END) to move the write pointer to the end.
  42     fd = os.open('/sys/kernel/debug/tracing/kprobe_events', os.O_WRONLY|os.O_CREAT|os.O_APPEND)
  43     for i, point in enumerate(instr_points):
  44
  45         kprobe_cmd = 'r:event_{} {}\n'.format(i, point).encode('utf-8')
  46         try:
  47             os.write(fd, kprobe_cmd)
  48         except OSError:
  49             continue
  50     os.close(fd)
  51     print(' Done.')
  52
  53 def set_kprobe_tracing_state(state):
  54     if state not in (0 ,1):
  55         raise ValueError
  56
  57     if state == 0:
  58         # Clear the content of the trace.
  59         open('/sys/kernel/debug/tracing/trace', 'w').close()
  60
  61     try:
  62         with open('/sys/kernel/debug/tracing/events/kprobes/enable', 'w') as enable_kprobe_file:
  63             enable_kprobe_file.write('{}\n'.format(state))
  64     except IOError:
  65         print('kprobes/enable file does not exist')
  66
  67 def run_workload():
  68     print('Running workload...', end='')
  69     sys.stdout.flush()
  70     workload = ['stress', '--cpu', '2', '--io', '4', '--vm', '2',
  71                 '--vm-bytes', '128M', '--hdd', '3', '--timeout', '3s']
  72     try:
  73         with open(os.devnull) as devnull:
  74             subprocess.call(workload, stdout=devnull, stderr=devnull)
  75     except OSError as e:
  76         print("Workload execution failed:", e, file=sys.stderr)
  77         pprint.pprint(workload)
  78
  79     print(' Done.')
  80
  81 def mount_tracingfs():
  82     with open(os.devnull) as devnull:
  83         subprocess.call(['mount', '-t', 'debugfs', 'nodev', '/sys/kernel/debug/'],
  84                 stdout=devnull, stderr=devnull)
  85
  86 def print_dashed_line():
  87     print('-'*100)
  88
  89 def main():
  90     assert(len(sys.argv) == 2)
  91
  92     instr_point_archive = sys.argv[1]
  93     # Load instrumentation points to disk and attach it to lava test run.
  94     instrumentation_points = load_instr_points(instr_point_archive)
  95
  96     mount_tracingfs()
  97
  98     # Loop over the list by enabling ranges of NB_KPROBES_PER_ITER kprobes.
  99     for i in range(int(len(instrumentation_points)/NB_KPROBES_PER_ITER)):
 100         print_dashed_line()
 101         print('Time now: {}, {} to {}'.format(datetime.datetime.now(), i*NB_KPROBES_PER_ITER, (i+1)*NB_KPROBES_PER_ITER))
 102         set_kprobe_tracing_state(0)
 103         enable_kprobe_events(instrumentation_points[i*NB_KPROBES_PER_ITER:(i+1)*NB_KPROBES_PER_ITER])
 104         set_kprobe_tracing_state(1)
 105         run_workload()
 106         print('\n')
 107
 108 if __name__ == "__main__":
 109     main()