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kernel/linux-rt-4.4.41/scripts/gdb/linux/cpus.py 3.48 KB
5113f6f70   김현기   kernel add
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  #
  # gdb helper commands and functions for Linux kernel debugging
  #
  #  per-cpu tools
  #
  # Copyright (c) Siemens AG, 2011-2013
  #
  # Authors:
  #  Jan Kiszka <jan.kiszka@siemens.com>
  #
  # This work is licensed under the terms of the GNU GPL version 2.
  #
  
  import gdb
  
  from linux import tasks, utils
  
  
  MAX_CPUS = 4096
  
  
  def get_current_cpu():
      if utils.get_gdbserver_type() == utils.GDBSERVER_QEMU:
          return gdb.selected_thread().num - 1
      elif utils.get_gdbserver_type() == utils.GDBSERVER_KGDB:
          tid = gdb.selected_thread().ptid[2]
          if tid > (0x100000000 - MAX_CPUS - 2):
              return 0x100000000 - tid - 2
          else:
              return tasks.get_thread_info(tasks.get_task_by_pid(tid))['cpu']
      else:
          raise gdb.GdbError("Sorry, obtaining the current CPU is not yet "
                             "supported with this gdb server.")
  
  
  def per_cpu(var_ptr, cpu):
      if cpu == -1:
          cpu = get_current_cpu()
      if utils.is_target_arch("sparc:v9"):
          offset = gdb.parse_and_eval(
              "trap_block[{0}].__per_cpu_base".format(str(cpu)))
      else:
          try:
              offset = gdb.parse_and_eval(
                  "__per_cpu_offset[{0}]".format(str(cpu)))
          except gdb.error:
              # !CONFIG_SMP case
              offset = 0
      pointer = var_ptr.cast(utils.get_long_type()) + offset
      return pointer.cast(var_ptr.type).dereference()
  
  
  cpu_mask = {}
  
  
  def cpu_mask_invalidate(event):
      global cpu_mask
      cpu_mask = {}
      gdb.events.stop.disconnect(cpu_mask_invalidate)
      if hasattr(gdb.events, 'new_objfile'):
          gdb.events.new_objfile.disconnect(cpu_mask_invalidate)
  
  
  def cpu_list(mask_name):
      global cpu_mask
      mask = None
      if mask_name in cpu_mask:
          mask = cpu_mask[mask_name]
      if mask is None:
          mask = gdb.parse_and_eval(mask_name + ".bits")
          if hasattr(gdb, 'events'):
              cpu_mask[mask_name] = mask
              gdb.events.stop.connect(cpu_mask_invalidate)
              if hasattr(gdb.events, 'new_objfile'):
                  gdb.events.new_objfile.connect(cpu_mask_invalidate)
      bits_per_entry = mask[0].type.sizeof * 8
      num_entries = mask.type.sizeof * 8 / bits_per_entry
      entry = -1
      bits = 0
  
      while True:
          while bits == 0:
              entry += 1
              if entry == num_entries:
                  return
              bits = mask[entry]
              if bits != 0:
                  bit = 0
                  break
  
          while bits & 1 == 0:
              bits >>= 1
              bit += 1
  
          cpu = entry * bits_per_entry + bit
  
          bits >>= 1
          bit += 1
  
          yield cpu
  
  
  class PerCpu(gdb.Function):
      """Return per-cpu variable.
  
  $lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the
  given CPU number. If CPU is omitted, the CPU of the current context is used.
  Note that VAR has to be quoted as string."""
  
      def __init__(self):
          super(PerCpu, self).__init__("lx_per_cpu")
  
      def invoke(self, var_name, cpu=-1):
          var_ptr = gdb.parse_and_eval("&" + var_name.string())
          return per_cpu(var_ptr, cpu)
  
  
  PerCpu()
  
  
  class LxCurrentFunc(gdb.Function):
      """Return current task.
  
  $lx_current([CPU]): Return the per-cpu task variable for the given CPU
  number. If CPU is omitted, the CPU of the current context is used."""
  
      def __init__(self):
          super(LxCurrentFunc, self).__init__("lx_current")
  
      def invoke(self, cpu=-1):
          var_ptr = gdb.parse_and_eval("&current_task")
          return per_cpu(var_ptr, cpu).dereference()
  
  
  LxCurrentFunc()