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 <[email protected]>
  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, lists
  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 = init_task
  26
  27     while True:
  28         thread_head = t['signal']['thread_head']
  29         for thread in lists.list_for_each_entry(thread_head, task_ptr_type, 'thread_node'):
  30             yield thread
  31
  32         t = utils.container_of(t['tasks']['next'],
  33                                task_ptr_type, "tasks")
  34         if t == init_task:
  35             return
  36
  37
  38 def get_task_by_pid(pid):
  39     for task in task_lists():
  40         if int(task['pid']) == pid:
  41             return task
  42     return None
  43
  44
  45 class LxTaskByPidFunc(gdb.Function):
  46     """Find Linux task by PID and return the task_struct variable.
  47
  48 $lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and
  49 return that task_struct variable which PID matches."""
  50
  51     def __init__(self):
  52         super(LxTaskByPidFunc, self).__init__("lx_task_by_pid")
  53
  54     def invoke(self, pid):
  55         task = get_task_by_pid(pid)
  56         if task:
  57             return task.dereference()
  58         else:
  59             raise gdb.GdbError("No task of PID " + str(pid))
  60
  61
  62 LxTaskByPidFunc()
  63
  64
  65 class LxPs(gdb.Command):
  66     """Dump Linux tasks."""
  67
  68     def __init__(self):
  69         super(LxPs, self).__init__("lx-ps", gdb.COMMAND_DATA)
  70
  71     def invoke(self, arg, from_tty):
  72         gdb.write("{:>10} {:>12} {:>7}\n".format("TASK", "PID", "COMM"))
  73         for task in task_lists():
  74             gdb.write("{} {:^5} {}\n".format(
  75                 task.format_string().split()[0],
  76                 task["pid"].format_string(),
  77                 task["comm"].string()))
  78
  79
  80 LxPs()
  81
  82
  83 thread_info_type = utils.CachedType("struct thread_info")
  84
  85 ia64_task_size = None
  86
  87
  88 def get_thread_info(task):
  89     thread_info_ptr_type = thread_info_type.get_type().pointer()
  90     if utils.is_target_arch("ia64"):
  91         global ia64_task_size
  92         if ia64_task_size is None:
  93             ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
  94         thread_info_addr = task.address + ia64_task_size
  95         thread_info = thread_info_addr.cast(thread_info_ptr_type)
  96     else:
  97         if task.type.fields()[0].type == thread_info_type.get_type():
  98             return task['thread_info']
  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()
 117
 118
 119 class LxThreadInfoByPidFunc (gdb.Function):
 120     """Calculate Linux thread_info from task variable found by pid
 121
 122 $lx_thread_info_by_pid(PID): Given PID, return the corresponding thread_info
 123 variable."""
 124
 125     def __init__(self):
 126         super(LxThreadInfoByPidFunc, self).__init__("lx_thread_info_by_pid")
 127
 128     def invoke(self, pid):
 129         task = get_task_by_pid(pid)
 130         if task:
 131             return get_thread_info(task.dereference())
 132         else:
 133             raise gdb.GdbError("No task of PID " + str(pid))
 134
 135
 136 LxThreadInfoByPidFunc()