2 # gdb helper commands and functions for Linux kernel debugging
4 # kernel log buffer dump
6 # Copyright (c) Siemens AG, 2011, 2012
9 # Jan Kiszka <jan.kiszka@siemens.com>
11 # This work is licensed under the terms of the GNU GPL version 2.
17 from linux
import utils
20 class LxDmesg(gdb
.Command
):
21 """Print Linux kernel log buffer."""
24 super(LxDmesg
, self
).__init
__("lx-dmesg", gdb
.COMMAND_DATA
)
26 def invoke(self
, arg
, from_tty
):
27 log_buf_addr
= int(str(gdb
.parse_and_eval(
28 "(void *)'printk.c'::log_buf")).split()[0], 16)
29 log_first_idx
= int(gdb
.parse_and_eval("'printk.c'::log_first_idx"))
30 log_next_idx
= int(gdb
.parse_and_eval("'printk.c'::log_next_idx"))
31 log_buf_len
= int(gdb
.parse_and_eval("'printk.c'::log_buf_len"))
33 inf
= gdb
.inferiors()[0]
34 start
= log_buf_addr
+ log_first_idx
35 if log_first_idx
< log_next_idx
:
37 length
= log_next_idx
- log_first_idx
38 log_buf
= utils
.read_memoryview(inf
, start
, length
).tobytes()
40 log_buf_2nd_half
= log_buf_len
- log_first_idx
41 a
= utils
.read_memoryview(inf
, start
, log_buf_2nd_half
)
42 b
= utils
.read_memoryview(inf
, log_buf_addr
, log_next_idx
)
43 log_buf
= a
.tobytes() + b
.tobytes()
46 while pos
< log_buf
.__len
__():
47 length
= utils
.read_u16(log_buf
[pos
+ 8:pos
+ 10])
49 if log_buf_2nd_half
== -1:
50 gdb
.write("Corrupted log buffer!\n")
52 pos
= log_buf_2nd_half
55 text_len
= utils
.read_u16(log_buf
[pos
+ 10:pos
+ 12])
56 text
= log_buf
[pos
+ 16:pos
+ 16 + text_len
].decode(
57 encoding
='utf8', errors
='replace')
58 time_stamp
= utils
.read_u64(log_buf
[pos
:pos
+ 8])
60 for line
in text
.splitlines():
61 msg
= u
"[{time:12.6f}] {line}\n".format(
62 time
=time_stamp
/ 1000000000.0,
64 # With python2 gdb.write will attempt to convert unicode to
65 # ascii and might fail so pass an utf8-encoded str instead.
66 if sys
.hexversion
< 0x03000000:
67 msg
= msg
.encode(encoding
='utf8', errors
='replace')