[PATCH] kdump: Documentation for Kdump
[linux-2.6.git] / Documentation / kdump / gdbmacros.txt
1 #
2 # This file contains a few gdb macros (user defined commands) to extract
3 # useful information from kernel crashdump (kdump) like stack traces of
4 # all the processes or a particular process and trapinfo.
5 #
6 # These macros can be used by copying this file in .gdbinit (put in home
7 # directory or current directory) or by invoking gdb command with
8 # --command=<command-file-name> option
9 #
10 # Credits:
11 # Alexander Nyberg <alexn@telia.com>
12 # V Srivatsa <vatsa@in.ibm.com>
13 # Maneesh Soni <maneesh@in.ibm.com>
14 #
15
16 define bttnobp
17         set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
18         set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
19         set $init_t=&init_task
20         set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
21         while ($next_t != $init_t)
22                 set $next_t=(struct task_struct *)$next_t
23                 printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
24                 printf "===================\n"
25                 set var $stackp = $next_t.thread.esp
26                 set var $stack_top = ($stackp & ~4095) + 4096
27
28                 while ($stackp < $stack_top)
29                         if (*($stackp) > _stext && *($stackp) < _sinittext)
30                                 info symbol *($stackp)
31                         end
32                         set $stackp += 4
33                 end
34                 set $next_th=(((char *)$next_t->pids[1].pid_list.next) - $pid_off)
35                 while ($next_th != $next_t)
36                         set $next_th=(struct task_struct *)$next_th
37                         printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
38                         printf "===================\n"
39                         set var $stackp = $next_t.thread.esp
40                         set var $stack_top = ($stackp & ~4095) + 4096
41
42                         while ($stackp < $stack_top)
43                                 if (*($stackp) > _stext && *($stackp) < _sinittext)
44                                         info symbol *($stackp)
45                                 end
46                                 set $stackp += 4
47                         end
48                         set $next_th=(((char *)$next_th->pids[1].pid_list.next) - $pid_off)
49                 end
50                 set $next_t=(char *)($next_t->tasks.next) - $tasks_off
51         end
52 end
53 document bttnobp
54         dump all thread stack traces on a kernel compiled with !CONFIG_FRAME_POINTER
55 end
56
57 define btt
58         set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
59         set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
60         set $init_t=&init_task
61         set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
62         while ($next_t != $init_t)
63                 set $next_t=(struct task_struct *)$next_t
64                 printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
65                 printf "===================\n"
66                 set var $stackp = $next_t.thread.esp
67                 set var $stack_top = ($stackp & ~4095) + 4096
68                 set var $stack_bot = ($stackp & ~4095)
69
70                 set $stackp = *($stackp)
71                 while (($stackp < $stack_top) && ($stackp > $stack_bot))
72                         set var $addr = *($stackp + 4)
73                         info symbol $addr
74                         set $stackp = *($stackp)
75                 end
76
77                 set $next_th=(((char *)$next_t->pids[1].pid_list.next) - $pid_off)
78                 while ($next_th != $next_t)
79                         set $next_th=(struct task_struct *)$next_th
80                         printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
81                         printf "===================\n"
82                         set var $stackp = $next_t.thread.esp
83                         set var $stack_top = ($stackp & ~4095) + 4096
84                         set var $stack_bot = ($stackp & ~4095)
85
86                         set $stackp = *($stackp)
87                         while (($stackp < $stack_top) && ($stackp > $stack_bot))
88                                 set var $addr = *($stackp + 4)
89                                 info symbol $addr
90                                 set $stackp = *($stackp)
91                         end
92                         set $next_th=(((char *)$next_th->pids[1].pid_list.next) - $pid_off)
93                 end
94                 set $next_t=(char *)($next_t->tasks.next) - $tasks_off
95         end
96 end
97 document btt
98         dump all thread stack traces on a kernel compiled with CONFIG_FRAME_POINTER
99 end
100
101 define btpid
102         set var $pid = $arg0
103         set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
104         set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
105         set $init_t=&init_task
106         set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
107         set var $pid_task = 0
108
109         while ($next_t != $init_t)
110                 set $next_t=(struct task_struct *)$next_t
111
112                 if ($next_t.pid == $pid)
113                         set $pid_task = $next_t
114                 end
115
116                 set $next_th=(((char *)$next_t->pids[1].pid_list.next) - $pid_off)
117                 while ($next_th != $next_t)
118                         set $next_th=(struct task_struct *)$next_th
119                         if ($next_th.pid == $pid)
120                                 set $pid_task = $next_th
121                         end
122                         set $next_th=(((char *)$next_th->pids[1].pid_list.next) - $pid_off)
123                 end
124                 set $next_t=(char *)($next_t->tasks.next) - $tasks_off
125         end
126
127         printf "\npid %d; comm %s:\n", $pid_task.pid, $pid_task.comm
128         printf "===================\n"
129         set var $stackp = $pid_task.thread.esp
130         set var $stack_top = ($stackp & ~4095) + 4096
131         set var $stack_bot = ($stackp & ~4095)
132
133         set $stackp = *($stackp)
134         while (($stackp < $stack_top) && ($stackp > $stack_bot))
135                 set var $addr = *($stackp + 4)
136                 info symbol $addr
137                 set $stackp = *($stackp)
138         end
139 end
140 document btpid
141         backtrace of pid
142 end
143
144
145 define trapinfo
146         set var $pid = $arg0
147         set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
148         set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
149         set $init_t=&init_task
150         set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
151         set var $pid_task = 0
152
153         while ($next_t != $init_t)
154                 set $next_t=(struct task_struct *)$next_t
155
156                 if ($next_t.pid == $pid)
157                         set $pid_task = $next_t
158                 end
159
160                 set $next_th=(((char *)$next_t->pids[1].pid_list.next) - $pid_off)
161                 while ($next_th != $next_t)
162                         set $next_th=(struct task_struct *)$next_th
163                         if ($next_th.pid == $pid)
164                                 set $pid_task = $next_th
165                         end
166                         set $next_th=(((char *)$next_th->pids[1].pid_list.next) - $pid_off)
167                 end
168                 set $next_t=(char *)($next_t->tasks.next) - $tasks_off
169         end
170
171         printf "Trapno %ld, cr2 0x%lx, error_code %ld\n", $pid_task.thread.trap_no, \
172                                 $pid_task.thread.cr2, $pid_task.thread.error_code
173
174 end
175 document trapinfo
176         Run info threads and lookup pid of thread #1
177         'trapinfo <pid>' will tell you by which trap & possibly
178         addresthe kernel paniced.
179 end