xref: /linux/scripts/gdb/linux/tasks.py (revision 2da68a77) 
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
14import gdb
15
16from linux import utils
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 = 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
42def 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
49class LxTaskByPidFunc(gdb.Function):
50    """Find Linux task by PID and return the task_struct variable.
51
52$lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and
53return that task_struct variable which PID matches."""
54
55    def __init__(self):
56        super(LxTaskByPidFunc, self).__init__("lx_task_by_pid")
57
58    def invoke(self, pid):
59        task = get_task_by_pid(pid)
60        if task:
61            return task.dereference()
62        else:
63            raise gdb.GdbError("No task of PID " + str(pid))
64
65
66LxTaskByPidFunc()
67
68
69class LxPs(gdb.Command):
70    """Dump Linux tasks."""
71
72    def __init__(self):
73        super(LxPs, self).__init__("lx-ps", gdb.COMMAND_DATA)
74
75    def invoke(self, arg, from_tty):
76        gdb.write("{:>10} {:>12} {:>7}\n".format("TASK", "PID", "COMM"))
77        for task in task_lists():
78            gdb.write("{} {:^5} {}\n".format(
79                task.format_string().split()[0],
80                task["pid"].format_string(),
81                task["comm"].string()))
82
83
84LxPs()
85
86
87thread_info_type = utils.CachedType("struct thread_info")
88
89ia64_task_size = None
90
91
92def get_thread_info(task):
93    thread_info_ptr_type = thread_info_type.get_type().pointer()
94    if utils.is_target_arch("ia64"):
95        global ia64_task_size
96        if ia64_task_size is None:
97            ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
98        thread_info_addr = task.address + ia64_task_size
99        thread_info = thread_info_addr.cast(thread_info_ptr_type)
100    else:
101        if task.type.fields()[0].type == thread_info_type.get_type():
102            return task['thread_info']
103        thread_info = task['stack'].cast(thread_info_ptr_type)
104    return thread_info.dereference()
105
106
107class LxThreadInfoFunc (gdb.Function):
108    """Calculate Linux thread_info from task variable.
109
110$lx_thread_info(TASK): Given TASK, return the corresponding thread_info
111variable."""
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
120LxThreadInfoFunc()
121
122
123class 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
127variable."""
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
140LxThreadInfoByPidFunc()
141