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 14import gdb 15 16from linux import utils 17 18 19task_type = utils.CachedType("struct task_struct") 20 21 22class TaskList: 23 def __init__(self): 24 global task_type 25 self.task_ptr_type = task_type.get_type().pointer() 26 self.init_task = gdb.parse_and_eval("init_task") 27 self.curr_group = self.init_task.address 28 self.curr_task = None 29 30 def __iter__(self): 31 return self 32 33 def next(self): 34 t = self.curr_task 35 if not t or t == self.curr_group: 36 self.curr_group = \ 37 utils.container_of(self.curr_group['tasks']['next'], 38 self.task_ptr_type, "tasks") 39 if self.curr_group == self.init_task.address: 40 raise StopIteration 41 t = self.curr_task = self.curr_group 42 else: 43 self.curr_task = \ 44 utils.container_of(t['thread_group']['next'], 45 self.task_ptr_type, "thread_group") 46 return t 47 48 49def get_task_by_pid(pid): 50 for task in TaskList(): 51 if int(task['pid']) == pid: 52 return task 53 return None 54 55 56class LxTaskByPidFunc(gdb.Function): 57 """Find Linux task by PID and return the task_struct variable. 58 59$lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and 60return that task_struct variable which PID matches.""" 61 62 def __init__(self): 63 super(LxTaskByPidFunc, self).__init__("lx_task_by_pid") 64 65 def invoke(self, pid): 66 task = get_task_by_pid(pid) 67 if task: 68 return task.dereference() 69 else: 70 raise gdb.GdbError("No task of PID " + str(pid)) 71 72 73LxTaskByPidFunc() 74