kernel/scripts/gdb/linux/tasks.py

   1 #
   2 # gdb helper commands and functions for Linux kernel debugging
   3 #
   4 #  task & thread tools
   5 #
   6 # Copyright (c) Siemens AG, 2011-2013
   7 #
   8 # Authors:
   9 #  Jan Kiszka <jan.kiszka@siemens.com>
  10 #
  11 # This work is licensed under the terms of the GNU GPL version 2.
  12 #
  13
  14 import gdb
  15
  16 from linux import utils
  17
  18
  19 task_type = utils.CachedType("struct task_struct")
  20
  21
  22 def task_lists():
  23     task_ptr_type = task_type.get_type().pointer()
  24     init_task = gdb.parse_and_eval("init_task").address
  25     t = g = init_task
  26
  27     while True:
  28         while True:
  29             yield t
  30
  31             t = utils.container_of(t['thread_group']['next'],
  32                                    task_ptr_type, "thread_group")
  33             if t == g:
  34                 break
  35
  36         t = g = utils.container_of(g['tasks']['next'],
  37                                    task_ptr_type, "tasks")
  38         if t == init_task:
  39             return
  40
  41
  42 def get_task_by_pid(pid):
  43     for task in task_lists():
  44         if int(task['pid']) == pid:
  45             return task
  46     return None
  47
  48
  49 class LxTaskByPidFunc(gdb.Function):
  50     """Find Linux task by PID and return the task_struct variable.
  51
  52 $lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and
  53 return that task_struct variable which PID matches."""
  54
  55     def __init__(self):
  56         super(LxTaskByPidFunc, self).__init__("lx_task_by_pid")
  57
  58     def invoke(self, pid):
  59         task = get_task_by_pid(pid)
  60         if task:
  61             return task.dereference()
  62         else:
  63             raise gdb.GdbError("No task of PID " + str(pid))
  64
  65
  66 LxTaskByPidFunc()
  67
  68
  69 class LxPs(gdb.Command):
  70     """Dump Linux tasks."""
  71
  72     def __init__(self):
  73         super(LxPs, self).__init__("lx-ps", gdb.COMMAND_DATA)
  74
  75     def invoke(self, arg, from_tty):
  76         for task in task_lists():
  77             gdb.write("{address} {pid} {comm}\n".format(
  78                 address=task,
  79                 pid=task["pid"],
  80                 comm=task["comm"].string()))
  81
  82 LxPs()
  83
  84
  85 thread_info_type = utils.CachedType("struct thread_info")
  86
  87 ia64_task_size = None
  88
  89
  90 def get_thread_info(task):
  91     thread_info_ptr_type = thread_info_type.get_type().pointer()
  92     if utils.is_target_arch("ia64"):
  93         global ia64_task_size
  94         if ia64_task_size is None:
  95             ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
  96         thread_info_addr = task.address + ia64_task_size
  97         thread_info = thread_info_addr.cast(thread_info_ptr_type)
  98     else:
  99         thread_info = task['stack'].cast(thread_info_ptr_type)
 100     return thread_info.dereference()
 101
 102
 103 class LxThreadInfoFunc (gdb.Function):
 104     """Calculate Linux thread_info from task variable.
 105
 106 $lx_thread_info(TASK): Given TASK, return the corresponding thread_info
 107 variable."""
 108
 109     def __init__(self):
 110         super(LxThreadInfoFunc, self).__init__("lx_thread_info")
 111
 112     def invoke(self, task):
 113         return get_thread_info(task)
 114
 115
 116 LxThreadInfoFunc()