xref: /linux-6.15/scripts/gdb/linux/tasks.py (revision 6ad18b73) 
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
22def task_lists():
23    global task_type
24    task_ptr_type = task_type.get_type().pointer()
25    init_task = gdb.parse_and_eval("init_task").address
26    t = g = init_task
27
28    while True:
29        while True:
30            yield t
31
32            t = utils.container_of(t['thread_group']['next'],
33                                   task_ptr_type, "thread_group")
34            if t == g:
35                break
36
37        t = g = utils.container_of(g['tasks']['next'],
38                                   task_ptr_type, "tasks")
39        if t == init_task:
40            return
41
42
43def get_task_by_pid(pid):
44    for task in task_lists():
45        if int(task['pid']) == pid:
46            return task
47    return None
48
49
50class LxTaskByPidFunc(gdb.Function):
51    """Find Linux task by PID and return the task_struct variable.
52
53$lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and
54return that task_struct variable which PID matches."""
55
56    def __init__(self):
57        super(LxTaskByPidFunc, self).__init__("lx_task_by_pid")
58
59    def invoke(self, pid):
60        task = get_task_by_pid(pid)
61        if task:
62            return task.dereference()
63        else:
64            raise gdb.GdbError("No task of PID " + str(pid))
65
66
67LxTaskByPidFunc()
68
69
70thread_info_type = utils.CachedType("struct thread_info")
71
72ia64_task_size = None
73
74
75def get_thread_info(task):
76    global thread_info_type
77    thread_info_ptr_type = thread_info_type.get_type().pointer()
78    if utils.is_target_arch("ia64"):
79        global ia64_task_size
80        if ia64_task_size is None:
81            ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
82        thread_info_addr = task.address + ia64_task_size
83        thread_info = thread_info_addr.cast(thread_info_ptr_type)
84    else:
85        thread_info = task['stack'].cast(thread_info_ptr_type)
86    return thread_info.dereference()
87
88
89class LxThreadInfoFunc (gdb.Function):
90    """Calculate Linux thread_info from task variable.
91
92$lx_thread_info(TASK): Given TASK, return the corresponding thread_info
93variable."""
94
95    def __init__(self):
96        super(LxThreadInfoFunc, self).__init__("lx_thread_info")
97
98    def invoke(self, task):
99        return get_thread_info(task)
100
101
102LxThreadInfoFunc()
103