1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0+
3
4usage() {
5	echo Extract any RCU CPU stall warnings present in specified file.
6	echo Filter out clocksource lines.  Note that preceding-lines excludes the
7	echo initial line of the stall warning but trailing-lines includes it.
8	echo
9	echo Usage: $(basename $0) dmesg-file [ preceding-lines [ trailing-lines ] ]
10	echo
11	echo Error: $1
12}
13
14# Terminate the script, if the argument is missing
15
16if test -f "$1" && test -r "$1"
17then
18	:
19else
20	usage "Console log file \"$1\" missing or unreadable."
21	exit 1
22fi
23
24echo $1
25preceding_lines="${2-3}"
26trailing_lines="${3-10}"
27
28awk -v preceding_lines="$preceding_lines" -v trailing_lines="$trailing_lines" '
29suffix <= 0 {
30	for (i = preceding_lines; i > 0; i--)
31		last[i] = last[i - 1];
32	last[0] = $0;
33}
34
35suffix > 0 {
36	print $0;
37	suffix--;
38	if (suffix <= 0)
39		print "";
40}
41
42suffix <= 0 && /detected stall/ {
43	for (i = preceding_lines; i >= 0; i--)
44		if (last[i] != "")
45			print last[i];
46	suffix = trailing_lines;
47}' < "$1" | tr -d '\015' | grep -v clocksource
48
49