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         gdb.write("{:>10} {:>12} {:>7}\n".format("TASK", "PID", "COMM"))
  77         for task in task_lists():
  78             gdb.write("{} {:^5} {}\n".format(
  79                 task.format_string().split()[0],
  80                 task["pid"].format_string(),
  81                 task["comm"].string()))
  82
  83
  84 LxPs()
  85
  86
  87 thread_info_type = utils.CachedType("struct thread_info")
  88
  89 ia64_task_size = None
  90
  91
  92 def get_thread_info(task):
  93     thread_info_ptr_type = thread_info_type.get_type().pointer()
  94     if utils.is_target_arch("ia64"):
  95         global ia64_task_size
  96         if ia64_task_size is None:
  97             ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
  98         thread_info_addr = task.address + ia64_task_size
  99         thread_info = thread_info_addr.cast(thread_info_ptr_type)
 100     else:
 101         if task.type.fields()[0].type == thread_info_type.get_type():
 102             return task['thread_info']
 103         thread_info = task['stack'].cast(thread_info_ptr_type)
 104     return thread_info.dereference()
 105
 106
 107 class LxThreadInfoFunc (gdb.Function):
 108     """Calculate Linux thread_info from task variable.
 109
 110 $lx_thread_info(TASK): Given TASK, return the corresponding thread_info
 111 variable."""
 112
 113     def __init__(self):
 114         super(LxThreadInfoFunc, self).__init__("lx_thread_info")
 115
 116     def invoke(self, task):
 117         return get_thread_info(task)
 118
 119
 120 LxThreadInfoFunc()
 121
 122
 123 class LxThreadInfoByPidFunc (gdb.Function):
 124     """Calculate Linux thread_info from task variable found by pid
 125
 126 $lx_thread_info_by_pid(PID): Given PID, return the corresponding thread_info
 127 variable."""
 128
 129     def __init__(self):
 130         super(LxThreadInfoByPidFunc, self).__init__("lx_thread_info_by_pid")
 131
 132     def invoke(self, pid):
 133         task = get_task_by_pid(pid)
 134         if task:
 135             return get_thread_info(task.dereference())
 136         else:
 137             raise gdb.GdbError("No task of PID " + str(pid))
 138
 139
 140 LxThreadInfoByPidFunc()