scripts/qemugdb/aio.py

   1 #!/usr/bin/python
   2
   3 # GDB debugging support: aio/iohandler debug
   4 #
   5 # Copyright (c) 2015 Red Hat, Inc.
   6 #
   7 # Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
   8 #
   9 # This work is licensed under the terms of the GNU GPL, version 2 or
  10 # later.  See the COPYING file in the top-level directory.
  11 #
  12
  13 import gdb
  14 from qemugdb import coroutine
  15
  16 def isnull(ptr):
  17     return ptr == gdb.Value(0).cast(ptr.type)
  18
  19 def dump_aiocontext(context, verbose):
  20     '''Display a dump and backtrace for an aiocontext'''
  21     cur = context['aio_handlers']['lh_first']
  22     # Get pointers to functions we're going to process specially
  23     sym_fd_coroutine_enter = gdb.parse_and_eval('fd_coroutine_enter')
  24
  25     while not isnull(cur):
  26         entry = cur.dereference()
  27         gdb.write('----\n%s\n' % entry)
  28         if verbose and cur['io_read'] == sym_fd_coroutine_enter:
  29             coptr = (cur['opaque'].cast(gdb.lookup_type('FDYieldUntilData').pointer()))['co']
  30             coptr = coptr.cast(gdb.lookup_type('CoroutineUContext').pointer())
  31             coroutine.bt_jmpbuf(coptr['env']['__jmpbuf'])
  32         cur = cur['node']['le_next'];
  33
  34     gdb.write('----\n')
  35
  36 class HandlersCommand(gdb.Command):
  37     '''Display aio handlers'''
  38     def __init__(self):
  39         gdb.Command.__init__(self, 'qemu handlers', gdb.COMMAND_DATA,
  40                              gdb.COMPLETE_NONE)
  41
  42     def invoke(self, arg, from_tty):
  43         verbose = False
  44         argv = gdb.string_to_argv(arg)
  45
  46         if len(argv) > 0 and argv[0] == '--verbose':
  47             verbose = True
  48             argv.pop(0)
  49
  50         if len(argv) > 1:
  51             gdb.write('usage: qemu handlers [--verbose] [handler]\n')
  52             return
  53
  54         if len(argv) == 1:
  55             handlers_name = argv[0]
  56         else:
  57             handlers_name = 'qemu_aio_context'
  58         dump_aiocontext(gdb.parse_and_eval(handlers_name), verbose)