mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 09:59:32 +00:00
46d10a0943
Use errors=replace because it is never desirable for lx-dmesg to fail on string decoding errors, not even if the log buffer is corrupt and we show incorrect info. The kernel will sometimes print utf8, for example the copyright symbol from jffs2. In order to make this work specify 'utf8' everywhere because python2 otherwise defaults to 'ascii'. In theory the second errors='replace' is not be required because everything that can be decoded as utf8 should also be encodable back to utf8. But it's better to be extra safe here. It's worth noting that this is definitely not true for encoding='ascii', unknown characters are replaced with U+FFFD REPLACEMENT CHARACTER and they fail to encode back to ascii. Link: http://lkml.kernel.org/r/acee067f3345954ed41efb77b80eebdc038619c6.1498481469.git.leonard.crestez@nxp.com Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Acked-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Kieran Bingham <kieran@ksquared.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
73 lines
2.4 KiB
Python
73 lines
2.4 KiB
Python
#
|
|
# gdb helper commands and functions for Linux kernel debugging
|
|
#
|
|
# kernel log buffer dump
|
|
#
|
|
# Copyright (c) Siemens AG, 2011, 2012
|
|
#
|
|
# Authors:
|
|
# Jan Kiszka <jan.kiszka@siemens.com>
|
|
#
|
|
# This work is licensed under the terms of the GNU GPL version 2.
|
|
#
|
|
|
|
import gdb
|
|
import sys
|
|
|
|
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(
|
|
"(void *)'printk.c'::log_buf")).split()[0], 16)
|
|
log_first_idx = int(gdb.parse_and_eval("'printk.c'::log_first_idx"))
|
|
log_next_idx = int(gdb.parse_and_eval("'printk.c'::log_next_idx"))
|
|
log_buf_len = int(gdb.parse_and_eval("'printk.c'::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 = utils.read_memoryview(inf, start, length).tobytes()
|
|
else:
|
|
log_buf_2nd_half = log_buf_len - log_first_idx
|
|
a = utils.read_memoryview(inf, start, log_buf_2nd_half)
|
|
b = utils.read_memoryview(inf, log_buf_addr, log_next_idx)
|
|
log_buf = a.tobytes() + b.tobytes()
|
|
|
|
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])
|
|
text = log_buf[pos + 16:pos + 16 + text_len].decode(
|
|
encoding='utf8', errors='replace')
|
|
time_stamp = utils.read_u64(log_buf[pos:pos + 8])
|
|
|
|
for line in text.splitlines():
|
|
msg = u"[{time:12.6f}] {line}\n".format(
|
|
time=time_stamp / 1000000000.0,
|
|
line=line)
|
|
# With python2 gdb.write will attempt to convert unicode to
|
|
# ascii and might fail so pass an utf8-encoded str instead.
|
|
if sys.hexversion < 0x03000000:
|
|
msg = msg.encode(encoding='utf8', errors='replace')
|
|
gdb.write(msg)
|
|
|
|
pos += length
|
|
|
|
|
|
LxDmesg()
|