From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757401AbbA2GzV (ORCPT ); Thu, 29 Jan 2015 01:55:21 -0500 Received: from david.siemens.de ([192.35.17.14]:58352 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751890AbbA2GzT (ORCPT ); Thu, 29 Jan 2015 01:55:19 -0500 From: Jan Kiszka To: Andrew Morton , linux-kernel@vger.kernel.org Cc: Thomas Gleixner , Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Andi Kleen , Tom Tromey , Ben Widawsky , Borislav Petkov , Kay Sievers Subject: [PATCH v11 11/28] scripts/gdb: Add lx-dmesg command Date: Thu, 29 Jan 2015 07:46:30 +0100 Message-Id: X-Mailer: git-send-email 2.1.4 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 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 -- 2.1.4