xref: /linux-6.15/scripts/gdb/linux/tasks.py (revision 542e893f) 
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, lists
17
18
19task_type = utils.CachedType("struct task_struct")
20
21
22def 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
38def 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
45class LxTaskByPidFunc(gdb.Function):
46    """Find Linux task by PID and return the task_struct variable.
47
48$lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and
49return that task_struct variable which PID matches."""
50
51    def __init__(self):
52        super(LxTaskByPidFunc, self).__init__("lx_task_by_pid")
53
54    def invoke(self, pid):
55        task = get_task_by_pid(pid)
56        if task:
57            return task.dereference()
58        else:
59            raise gdb.GdbError("No task of PID " + str(pid))
60
61
62LxTaskByPidFunc()
63
64
65class LxPs(gdb.Command):
66    """Dump Linux tasks."""
67
68    def __init__(self):
69        super(LxPs, self).__init__("lx-ps", gdb.COMMAND_DATA)
70
71    def invoke(self, arg, from_tty):
72        gdb.write("{:>10} {:>12} {:>7}\n".format("TASK", "PID", "COMM"))
73        for task in task_lists():
74            gdb.write("{} {:^5} {}\n".format(
75                task.format_string().split()[0],
76                task["pid"].format_string(),
77                task["comm"].string()))
78
79
80LxPs()
81
82
83thread_info_type = utils.CachedType("struct thread_info")
84
85ia64_task_size = None
86
87
88def get_thread_info(task):
89    thread_info_ptr_type = thread_info_type.get_type().pointer()
90    if utils.is_target_arch("ia64"):
91        global ia64_task_size
92        if ia64_task_size is None:
93            ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
94        thread_info_addr = task.address + ia64_task_size
95        thread_info = thread_info_addr.cast(thread_info_ptr_type)
96    else:
97        if task.type.fields()[0].type == thread_info_type.get_type():
98            return task['thread_info']
99        thread_info = task['stack'].cast(thread_info_ptr_type)
100    return thread_info.dereference()
101
102
103class LxThreadInfoFunc (gdb.Function):
104    """Calculate Linux thread_info from task variable.
105
106$lx_thread_info(TASK): Given TASK, return the corresponding thread_info
107variable."""
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
116LxThreadInfoFunc()
117
118
119class 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
123variable."""
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
136LxThreadInfoByPidFunc()
137