script: improve markup_oops.pl to also decode oopses in modules

There has been some light flamewar on lkml about decoding oopses
in modules (as part of the crashdump flamewar).

Now this isn't rocket science, just the markup_oops.pl script
cheaped out and didn't handle modules. But really; a flamewar
all about that?? What happened to C++ in the kernel or reading
files from inside the kernel?

This patch adds module support to markup_oops.pl; it's not the
most pretty perl but it works for my testcases...

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

scripts/markup_oops.pl

@@ -1,5 +1,7 @@
 #!/usr/bin/perl -w
 
+use File::Basename;
+
 # Copyright 2008, Intel Corporation
 #
 # This file is part of the Linux kernel
@@ -13,30 +15,71 @@
 
 
 my $vmlinux_name = $ARGV[0];
-
+if (!defined($vmlinux_name)) {
+	my $kerver = `uname -r`;
+	chomp($kerver);
+	$vmlinux_name = "/lib/modules/$kerver/build/vmlinux";
+	print "No vmlinux specified, assuming $vmlinux_name\n";
+}
+my $filename = $vmlinux_name;
 #
 # Step 1: Parse the oops to find the EIP value
 #
 
 my $target = "0";
+my $function;
+my $module = "";
+my $func_offset;
+my $vmaoffset = 0;
+
 while (<STDIN>) {
-	if ($_ =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
+	my $line = $_;
+	if ($line =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
 		$target = $1;
 	}
-}
+	if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]/) {
+		$function = $1;
+		$func_offset = $2;
+	}
 
-if ($target =~ /^f8/) {
-	print "This script does not work on modules ... \n";
-	exit;
+	# check if it's a module
+	if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) {
+		$module = $3;
+	}
 }
 
+my $decodestart = hex($target) - hex($func_offset);
+my $decodestop = $decodestart + 8192;
 if ($target eq "0") {
 	print "No oops found!\n";
 	print "Usage: \n";
 	print "    dmesg | perl scripts/markup_oops.pl vmlinux\n";
 	exit;
 }
 
+# if it's a module, we need to find the .ko file and calculate a load offset
+if ($module ne "") {
+	my $dir = dirname($filename);
+	$dir = $dir . "/";
+	my $mod = $module . ".ko";
+	my $modulefile = `find $dir -name $mod | head -1`;
+	chomp($modulefile);
+	$filename = $modulefile;
+	if ($filename eq "") {
+		print "Module .ko file for $module not found. Aborting\n";
+		exit;
+	}
+	# ok so we found the module, now we need to calculate the vma offset
+	open(FILE, "objdump -dS $filename |") || die "Cannot start objdump";
+	while (<FILE>) {
+		if ($_ =~ /^([0-9a-f]+) \<$function\>\:/) {
+			my $fu = $1;
+			$vmaoffset = hex($target) - hex($fu) - hex($func_offset);
+		}
+	}
+	close(FILE);
+}
+
 my $counter = 0;
 my $state   = 0;
 my $center  = 0;
@@ -59,9 +102,7 @@ sub InRange {
 # 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 $vmlinux_name |") || die "Cannot start objdump";
+open(FILE, "objdump -dS --adjust-vma=$vmaoffset --start-address=$decodestart --stop-address=$decodestop $filename |") || die "Cannot start objdump";
 
 while (<FILE>) {
 	my $line = $_;