Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756043Ab3J1JjF (ORCPT ); Mon, 28 Oct 2013 05:39:05 -0400 Received: from david.siemens.de ([192.35.17.14]:15580 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755873Ab3J1JjC (ORCPT ); Mon, 28 Oct 2013 05:39:02 -0400 From: Jan Kiszka To: Andrew Morton , linux-kernel@vger.kernel.org Cc: Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Andi Kleen , Tom Tromey , Ben Widawsky , Borislav Petkov , Tatiana Al-Chueyr Martins , Kay Sievers Subject: [PATCH v6 11/21] scripts/gdb: Add lx-dmesg command Date: Mon, 28 Oct 2013 09:58:48 +0100 Message-Id: <387b1b969845799c0a1d9af23c9e9dfb4b7f4485.1382950737.git.jan.kiszka@siemens.com> X-Mailer: git-send-email 1.8.1.1.298.ge7eed54 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3204 Lines: 99 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. CC: Kay Sievers Signed-off-by: Jan Kiszka --- scripts/gdb/linux/dmesg.py | 64 ++++++++++++++++++++++++++++++++++++++++++++++ scripts/gdb/vmlinux-gdb.py | 1 + 2 files changed, 65 insertions(+) create mode 100644 scripts/gdb/linux/dmesg.py diff --git a/scripts/gdb/linux/dmesg.py b/scripts/gdb/linux/dmesg.py new file mode 100644 index 0000000..7650f24 --- /dev/null +++ b/scripts/gdb/linux/dmesg.py @@ -0,0 +1,64 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# kernel log buffer dump +# +# Copyright (c) Siemens AG, 2011, 2012 +# +# Authors: +# Jan Kiszka +# +# This work is licensed under the terms of the GNU GPL version 2. +# + +import gdb +import string + +from linux import utils + + +class LxDmesg(gdb.Command): + """Print Linux kernel log buffer.""" + + def __init__(self): + super(LxDmesg, self).__init__("lx-dmesg", gdb.COMMAND_DATA) + + def invoke(self, arg, from_tty): + log_buf_addr = int(str(gdb.parse_and_eval("log_buf")).split()[0], 16) + log_first_idx = int(gdb.parse_and_eval("log_first_idx")) + log_next_idx = int(gdb.parse_and_eval("log_next_idx")) + log_buf_len = int(gdb.parse_and_eval("log_buf_len")) + + inf = gdb.inferiors()[0] + start = log_buf_addr + log_first_idx + if log_first_idx < log_next_idx: + log_buf_2nd_half = -1 + length = log_next_idx - log_first_idx + log_buf = inf.read_memory(start, length) + else: + log_buf_2nd_half = log_buf_len - log_first_idx + log_buf = inf.read_memory(start, log_buf_2nd_half) + \ + inf.read_memory(log_buf_addr, log_next_idx) + + pos = 0 + while pos < log_buf.__len__(): + length = utils.read_u16(log_buf[pos + 8:pos + 10]) + if length == 0: + if log_buf_2nd_half == -1: + gdb.write("Corrupted log buffer!\n") + break + pos = log_buf_2nd_half + continue + + text_len = utils.read_u16(log_buf[pos + 10:pos + 12]) + time_stamp = utils.read_u64(log_buf[pos:pos + 8]) + + for line in log_buf[pos + 16:pos + 16 + text_len].splitlines(): + gdb.write("[{time:12.6f}] {line}\n".format( + time=time_stamp / 1000000000.0, + line=line)) + + pos += length + + +LxDmesg() diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py index cf2e716..fa66d23 100644 --- a/scripts/gdb/vmlinux-gdb.py +++ b/scripts/gdb/vmlinux-gdb.py @@ -25,3 +25,4 @@ else: import linux.utils import linux.symbols import linux.modules + import linux.dmesg -- 1.8.1.1.298.ge7eed54 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/