forked from mirrors/linux
ae7dbaad23
This pokes into the log buffer of the debugged kernel, dumping it to the gdb console. Helping in case the target should or can no longer execute dmesg itself. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
64 lines
1.9 KiB
Python
64 lines
1.9 KiB
Python
#
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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 string
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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("log_buf")).split()[0], 16)
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log_first_idx = int(gdb.parse_and_eval("log_first_idx"))
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log_next_idx = int(gdb.parse_and_eval("log_next_idx"))
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log_buf_len = int(gdb.parse_and_eval("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 = inf.read_memory(start, length)
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else:
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log_buf_2nd_half = log_buf_len - log_first_idx
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log_buf = inf.read_memory(start, log_buf_2nd_half) + \
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inf.read_memory(log_buf_addr, log_next_idx)
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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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time_stamp = utils.read_u64(log_buf[pos:pos + 8])
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for line in log_buf[pos + 16:pos + 16 + text_len].splitlines():
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gdb.write("[{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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pos += length
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LxDmesg()
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