Commit 5aea50b5 authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Linus Torvalds

scripts: script from kerneloops.org to pretty print oops dumps

We're struggling all the time to figure out where the code came from that
oopsed..  The script below (a adaption from a script used by
kerneloops.org) can help developers quite a bit, at least for non-module
cases.

It works and looks like this:

[/home/arjan/linux]$ dmesg | perl scripts/markup_oops.pl vmlinux
 {
 	struct agp_memory *memory;

 	memory = agp_allocate_memory(agp_bridge, pg_count, type);
 c055c10f:	89 c2                	mov    %eax,%edx
 	if (memory == NULL)
 c055c111:	74 19                	je     c055c12c <agp_allocate_memory_wrap+0x30>
 /* This function must only be called when current_controller != NULL */
 static void agp_insert_into_pool(struct agp_memory * temp)
 {
 	struct agp_memory *prev;

 	prev = agp_fe.current_controller->pool;
 c055c113:	a1 ec dc 8f c0       	mov    0xc08fdcec,%eax
*c055c118:	8b 40 10             	mov    0x10(%eax),%eax     <----- faulting instruction

 	if (prev != NULL) {
 c055c11b:	85 c0                	test   %eax,%eax
 c055c11d:	74 05                	je     c055c124 <agp_allocate_memory_wrap+0x28>
 		prev->prev = temp;
 c055c11f:	89 50 04             	mov    %edx,0x4(%eax)
 		temp->next = prev;
 c055c122:	89 02                	mov    %eax,(%edx)
 	}
 	agp_fe.current_controller->pool = temp;
 c055c124:	a1 ec dc 8f c0       	mov    0xc08fdcec,%eax
 c055c129:	89 50 10             	mov    %edx,0x10(%eax)
 	if (memory == NULL)
 		return NULL;

 	agp_insert_into_pool(memory);

so in this case, we faulted while dereferencing agp_fe.current_controller
pointer, and we get to see exactly which function and line it affects...
Personally I find this very useful, and I can see value for having this
script in the kernel for more-than-just-me to use.

Caveats:
* It only works for oopses not-in-modules
* It only works nicely for kernels compiled with CONFIG_DEBUG_INFO
* It's not very fast.
* It only works on x86
Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d6624f99
#!/usr/bin/perl -w
# Copyright 2008, Intel Corporation
#
# This file is part of the Linux kernel
#
# This program file is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; version 2 of the License.
#
# Authors:
# Arjan van de Ven <arjan@linux.intel.com>
my $vmlinux_name = $ARGV[0];
#
# Step 1: Parse the oops to find the EIP value
#
my $target = "0";
while (<STDIN>) {
if ($_ =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
$target = $1;
}
}
if ($target =~ /^f8/) {
print "This script does not work on modules ... \n";
exit;
}
if ($target eq "0") {
print "No oops found!\n";
print "Usage: \n";
print " dmesg | perl scripts/markup_oops.pl vmlinux\n";
exit;
}
my $counter = 0;
my $state = 0;
my $center = 0;
my @lines;
sub InRange {
my ($address, $target) = @_;
my $ad = "0x".$address;
my $ta = "0x".$target;
my $delta = hex($ad) - hex($ta);
if (($delta > -4096) && ($delta < 4096)) {
return 1;
}
return 0;
}
# first, parse the input into the lines array, but to keep size down,
# we only do this for 4Kb around the sweet spot
my $filename;
open(FILE, "objdump -dS $vmlinux_name |") || die "Cannot start objdump";
while (<FILE>) {
my $line = $_;
chomp($line);
if ($state == 0) {
if ($line =~ /^([a-f0-9]+)\:/) {
if (InRange($1, $target)) {
$state = 1;
}
}
} else {
if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) {
my $val = $1;
if (!InRange($val, $target)) {
last;
}
if ($val eq $target) {
$center = $counter;
}
}
$lines[$counter] = $line;
$counter = $counter + 1;
}
}
close(FILE);
if ($counter == 0) {
print "No matching code found \n";
exit;
}
if ($center == 0) {
print "No matching code found \n";
exit;
}
my $start;
my $finish;
my $codelines = 0;
my $binarylines = 0;
# now we go up and down in the array to find how much we want to print
$start = $center;
while ($start > 1) {
$start = $start - 1;
my $line = $lines[$start];
if ($line =~ /^([a-f0-9]+)\:/) {
$binarylines = $binarylines + 1;
} else {
$codelines = $codelines + 1;
}
if ($codelines > 10) {
last;
}
if ($binarylines > 20) {
last;
}
}
$finish = $center;
$codelines = 0;
$binarylines = 0;
while ($finish < $counter) {
$finish = $finish + 1;
my $line = $lines[$finish];
if ($line =~ /^([a-f0-9]+)\:/) {
$binarylines = $binarylines + 1;
} else {
$codelines = $codelines + 1;
}
if ($codelines > 10) {
last;
}
if ($binarylines > 20) {
last;
}
}
my $i;
my $fulltext = "";
$i = $start;
while ($i < $finish) {
if ($i == $center) {
$fulltext = $fulltext . "*$lines[$i] <----- faulting instruction\n";
} else {
$fulltext = $fulltext . " $lines[$i]\n";
}
$i = $i +1;
}
print $fulltext;
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