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("log_buf")).split()[0], 16)
28 log_first_idx = int(gdb.parse_and_eval("log_first_idx"))
29 log_next_idx = int(gdb.parse_and_eval("log_next_idx"))
30 log_buf_len = int(gdb.parse_and_eval("log_buf_len"))
32 inf = gdb.inferiors()[0]
33 start = log_buf_addr + log_first_idx
34 if log_first_idx < log_next_idx:
36 length = log_next_idx - log_first_idx
37 log_buf = inf.read_memory(start, length)
39 log_buf_2nd_half = log_buf_len - log_first_idx
40 log_buf = inf.read_memory(start, log_buf_2nd_half) + \
41 inf.read_memory(log_buf_addr, log_next_idx)
44 while pos < log_buf.__len__():
45 length = utils.read_u16(log_buf[pos + 8:pos + 10])
47 if log_buf_2nd_half == -1:
48 gdb.write("Corrupted log buffer!\n")
50 pos = log_buf_2nd_half
53 text_len = utils.read_u16(log_buf[pos + 10:pos + 12])
54 text = log_buf[pos + 16:pos + 16 + text_len]
55 time_stamp = utils.read_u64(log_buf[pos:pos + 8])
57 for line in memoryview(text).tobytes().splitlines():
58 gdb.write("[{time:12.6f}] {line}\n".format(
59 time=time_stamp / 1000000000.0,