xref: /linux-6.15/scripts/markup_oops.pl (revision c19ef7fd)
1#!/usr/bin/perl -w
2
3use File::Basename;
4
5# Copyright 2008, Intel Corporation
6#
7# This file is part of the Linux kernel
8#
9# This program file is free software; you can redistribute it and/or modify it
10# under the terms of the GNU General Public License as published by the
11# Free Software Foundation; version 2 of the License.
12#
13# Authors:
14# 	Arjan van de Ven <[email protected]>
15
16
17my $vmlinux_name = $ARGV[0];
18if (!defined($vmlinux_name)) {
19	my $kerver = `uname -r`;
20	chomp($kerver);
21	$vmlinux_name = "/lib/modules/$kerver/build/vmlinux";
22	print "No vmlinux specified, assuming $vmlinux_name\n";
23}
24my $filename = $vmlinux_name;
25#
26# Step 1: Parse the oops to find the EIP value
27#
28
29my $target = "0";
30my $function;
31my $module = "";
32my $func_offset;
33my $vmaoffset = 0;
34
35my %regs;
36
37
38sub parse_x86_regs
39{
40	my ($line) = @_;
41	if ($line =~ /EAX: ([0-9a-f]+) EBX: ([0-9a-f]+) ECX: ([0-9a-f]+) EDX: ([0-9a-f]+)/) {
42		$regs{"%eax"} = $1;
43		$regs{"%ebx"} = $2;
44		$regs{"%ecx"} = $3;
45		$regs{"%edx"} = $4;
46	}
47	if ($line =~ /ESI: ([0-9a-f]+) EDI: ([0-9a-f]+) EBP: ([0-9a-f]+) ESP: ([0-9a-f]+)/) {
48		$regs{"%esi"} = $1;
49		$regs{"%edi"} = $2;
50		$regs{"%esp"} = $4;
51	}
52}
53
54sub process_x86_regs
55{
56	my ($line, $cntr) = @_;
57	my $str = "";
58	if (length($line) < 40) {
59		return ""; # not an asm istruction
60	}
61
62	# find the arguments to the instruction
63	if ($line =~ /([0-9a-zA-Z\,\%\(\)\-\+]+)$/) {
64		$lastword = $1;
65	} else {
66		return "";
67	}
68
69	# we need to find the registers that get clobbered,
70	# since their value is no longer relevant for previous
71	# instructions in the stream.
72
73	$clobber = $lastword;
74	# first, remove all memory operands, they're read only
75	$clobber =~ s/\([a-z0-9\%\,]+\)//g;
76	# then, remove everything before the comma, thats the read part
77	$clobber =~ s/.*\,//g;
78
79	# if this is the instruction that faulted, we haven't actually done
80	# the write yet... nothing is clobbered.
81	if ($cntr == 0) {
82		$clobber = "";
83	}
84
85	foreach $reg (keys(%regs)) {
86		my $val = $regs{$reg};
87		# first check if we're clobbering this register; if we do
88		# we print it with a =>, and then delete its value
89		if ($clobber =~ /$reg/) {
90			if (length($val) > 0) {
91				$str = $str . " $reg => $val ";
92			}
93			$regs{$reg} = "";
94			$val = "";
95		}
96		# now check if we're reading this register
97		if ($lastword =~ /$reg/) {
98			if (length($val) > 0) {
99				$str = $str . " $reg = $val ";
100			}
101		}
102	}
103	return $str;
104}
105
106# parse the oops
107while (<STDIN>) {
108	my $line = $_;
109	if ($line =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
110		$target = $1;
111	}
112	if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]/) {
113		$function = $1;
114		$func_offset = $2;
115	}
116
117	# check if it's a module
118	if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) {
119		$module = $3;
120	}
121	parse_x86_regs($line);
122}
123
124my $decodestart = hex($target) - hex($func_offset);
125my $decodestop = hex($target) + 8192;
126if ($target eq "0") {
127	print "No oops found!\n";
128	print "Usage: \n";
129	print "    dmesg | perl scripts/markup_oops.pl vmlinux\n";
130	exit;
131}
132
133# if it's a module, we need to find the .ko file and calculate a load offset
134if ($module ne "") {
135	my $dir = dirname($filename);
136	$dir = $dir . "/";
137	my $mod = $module . ".ko";
138	my $modulefile = `find $dir -name $mod | head -1`;
139	chomp($modulefile);
140	$filename = $modulefile;
141	if ($filename eq "") {
142		print "Module .ko file for $module not found. Aborting\n";
143		exit;
144	}
145	# ok so we found the module, now we need to calculate the vma offset
146	open(FILE, "objdump -dS $filename |") || die "Cannot start objdump";
147	while (<FILE>) {
148		if ($_ =~ /^([0-9a-f]+) \<$function\>\:/) {
149			my $fu = $1;
150			$vmaoffset = hex($target) - hex($fu) - hex($func_offset);
151		}
152	}
153	close(FILE);
154}
155
156my $counter = 0;
157my $state   = 0;
158my $center  = 0;
159my @lines;
160my @reglines;
161
162sub InRange {
163	my ($address, $target) = @_;
164	my $ad = "0x".$address;
165	my $ta = "0x".$target;
166	my $delta = hex($ad) - hex($ta);
167
168	if (($delta > -4096) && ($delta < 4096)) {
169		return 1;
170	}
171	return 0;
172}
173
174
175
176# first, parse the input into the lines array, but to keep size down,
177# we only do this for 4Kb around the sweet spot
178
179open(FILE, "objdump -dS --adjust-vma=$vmaoffset --start-address=$decodestart --stop-address=$decodestop $filename |") || die "Cannot start objdump";
180
181while (<FILE>) {
182	my $line = $_;
183	chomp($line);
184	if ($state == 0) {
185		if ($line =~ /^([a-f0-9]+)\:/) {
186			if (InRange($1, $target)) {
187				$state = 1;
188			}
189		}
190	} else {
191		if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) {
192			my $val = $1;
193			if (!InRange($val, $target)) {
194				last;
195			}
196			if ($val eq $target) {
197				$center = $counter;
198			}
199		}
200		$lines[$counter] = $line;
201
202		$counter = $counter + 1;
203	}
204}
205
206close(FILE);
207
208if ($counter == 0) {
209	print "No matching code found \n";
210	exit;
211}
212
213if ($center == 0) {
214	print "No matching code found \n";
215	exit;
216}
217
218my $start;
219my $finish;
220my $codelines = 0;
221my $binarylines = 0;
222# now we go up and down in the array to find how much we want to print
223
224$start = $center;
225
226while ($start > 1) {
227	$start = $start - 1;
228	my $line = $lines[$start];
229	if ($line =~ /^([a-f0-9]+)\:/) {
230		$binarylines = $binarylines + 1;
231	} else {
232		$codelines = $codelines + 1;
233	}
234	if ($codelines > 10) {
235		last;
236	}
237	if ($binarylines > 20) {
238		last;
239	}
240}
241
242
243$finish = $center;
244$codelines = 0;
245$binarylines = 0;
246while ($finish < $counter) {
247	$finish = $finish + 1;
248	my $line = $lines[$finish];
249	if ($line =~ /^([a-f0-9]+)\:/) {
250		$binarylines = $binarylines + 1;
251	} else {
252		$codelines = $codelines + 1;
253	}
254	if ($codelines > 10) {
255		last;
256	}
257	if ($binarylines > 20) {
258		last;
259	}
260}
261
262
263my $i;
264
265
266# start annotating the registers in the asm.
267# this goes from the oopsing point back, so that the annotator
268# can track (opportunistically) which registers got written and
269# whos value no longer is relevant.
270
271$i = $center;
272while ($i >= $start) {
273	$reglines[$i] = process_x86_regs($lines[$i], $center - $i);
274	$i = $i - 1;
275}
276
277$i = $start;
278while ($i < $finish) {
279	my $line;
280	if ($i == $center) {
281		$line =  "*$lines[$i] ";
282	} else {
283		$line =  " $lines[$i] ";
284	}
285	print $line;
286	if (defined($reglines[$i]) && length($reglines[$i]) > 0) {
287		my $c = 60 - length($line);
288		while ($c > 0) { print " "; $c = $c - 1; };
289		print "| $reglines[$i]";
290	}
291	if ($i == $center) {
292		print "<--- faulting instruction";
293	}
294	print "\n";
295	$i = $i +1;
296}
297
298