74 lines
2.4 KiB
Python
Executable file
74 lines
2.4 KiB
Python
Executable file
#
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# gdb helper commands and functions for Linux kernel debugging
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#
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# kernel log buffer dump
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#
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# Copyright (c) Siemens AG, 2011, 2012
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#
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# Authors:
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# Jan Kiszka <jan.kiszka@siemens.com>
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#
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# This work is licensed under the terms of the GNU GPL version 2.
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#
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import gdb
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import sys
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from linux import utils
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class LxDmesg(gdb.Command):
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"""Print Linux kernel log buffer."""
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def __init__(self):
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super(LxDmesg, self).__init__("lx-dmesg", gdb.COMMAND_DATA)
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def invoke(self, arg, from_tty):
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log_buf_addr = int(str(gdb.parse_and_eval(
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"(void *)'printk.c'::log_buf")).split()[0], 16)
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log_first_idx = int(gdb.parse_and_eval("'printk.c'::log_first_idx"))
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log_next_idx = int(gdb.parse_and_eval("'printk.c'::log_next_idx"))
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log_buf_len = int(gdb.parse_and_eval("'printk.c'::log_buf_len"))
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inf = gdb.inferiors()[0]
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start = log_buf_addr + log_first_idx
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if log_first_idx < log_next_idx:
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log_buf_2nd_half = -1
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length = log_next_idx - log_first_idx
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log_buf = utils.read_memoryview(inf, start, length).tobytes()
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else:
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log_buf_2nd_half = log_buf_len - log_first_idx
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a = utils.read_memoryview(inf, start, log_buf_2nd_half)
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b = utils.read_memoryview(inf, log_buf_addr, log_next_idx)
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log_buf = a.tobytes() + b.tobytes()
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pos = 0
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while pos < log_buf.__len__():
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length = utils.read_u16(log_buf[pos + 8:pos + 10])
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if length == 0:
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if log_buf_2nd_half == -1:
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gdb.write("Corrupted log buffer!\n")
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break
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pos = log_buf_2nd_half
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continue
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text_len = utils.read_u16(log_buf[pos + 10:pos + 12])
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text = log_buf[pos + 16:pos + 16 + text_len].decode(
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encoding='utf8', errors='replace')
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time_stamp = utils.read_u64(log_buf[pos:pos + 8])
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for line in text.splitlines():
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msg = u"[{time:12.6f}] {line}\n".format(
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time=time_stamp / 1000000000.0,
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line=line)
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# With python2 gdb.write will attempt to convert unicode to
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# ascii and might fail so pass an utf8-encoded str instead.
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if sys.hexversion < 0x03000000:
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msg = msg.encode(encoding='utf8', errors='replace')
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gdb.write(msg)
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pos += length
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LxDmesg()
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