xref: /linux-6.15/scripts/gdb/linux/tasks.py (revision 276d97d9) 
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    def next(self):
49        return self.__next__()
50
51def get_task_by_pid(pid):
52    for task in TaskList():
53        if int(task['pid']) == pid:
54            return task
55    return None
56
57
58class LxTaskByPidFunc(gdb.Function):
59    """Find Linux task by PID and return the task_struct variable.
60
61$lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and
62return that task_struct variable which PID matches."""
63
64    def __init__(self):
65        super(LxTaskByPidFunc, self).__init__("lx_task_by_pid")
66
67    def invoke(self, pid):
68        task = get_task_by_pid(pid)
69        if task:
70            return task.dereference()
71        else:
72            raise gdb.GdbError("No task of PID " + str(pid))
73
74
75LxTaskByPidFunc()
76
77
78thread_info_type = utils.CachedType("struct thread_info")
79
80ia64_task_size = None
81
82
83def get_thread_info(task):
84    global thread_info_type
85    thread_info_ptr_type = thread_info_type.get_type().pointer()
86    if utils.is_target_arch("ia64"):
87        global ia64_task_size
88        if ia64_task_size is None:
89            ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
90        thread_info_addr = task.address + ia64_task_size
91        thread_info = thread_info_addr.cast(thread_info_ptr_type)
92    else:
93        thread_info = task['stack'].cast(thread_info_ptr_type)
94    return thread_info.dereference()
95
96
97class LxThreadInfoFunc (gdb.Function):
98    """Calculate Linux thread_info from task variable.
99
100$lx_thread_info(TASK): Given TASK, return the corresponding thread_info
101variable."""
102
103    def __init__(self):
104        super(LxThreadInfoFunc, self).__init__("lx_thread_info")
105
106    def invoke(self, task):
107        return get_thread_info(task)
108
109
110LxThreadInfoFunc()
111