markup_oops.pl: add options to improve cross-sompilation environments

The markup_oops.pl have 3 troubles to support cross-compiler environment:
1.  It use objdump directly.
2.  It use modinfo to get the message of module.
3.  It use hex function that cannot support 64-bit number in 32-bit arch.

This patch add 3 options to markup_oops.pl:
1. -c CROSS_COMPILE	Specify the prefix used for toolchain.
2. -m MODULE_DIRNAME	Specify the module directory name.
3. Change hex function to Math::BigInt->from_hex.

After this patch, parse the x8664 oops in x86, we can:
cat amd64m | perl ~/kernel/tmp/m.pl -c /home/teawater/kernel/bin/x8664- -m ./e.ko vmlinux

Thanks,
Hui

Signed-off-by: Hui Zhu <teawater@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: ozan@pardus.org.tr
Cc: Matthew Wilcox <willy@linux.intel.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/markup_oops.pl

@@ -2,6 +2,7 @@
 
 use File::Basename;
 use Math::BigInt;
+use Getopt::Long;
 
 # Copyright 2008, Intel Corporation
 #
@@ -15,17 +16,26 @@
 # 	Arjan van de Ven <arjan@linux.intel.com>
 
 
-my $vmlinux_name = $ARGV[0];
+my $cross_compile = "";
+my $vmlinux_name = "";
+my $modulefile = "";
+
+# Get options
+Getopt::Long::GetOptions(
+	'cross-compile|c=s'	=> \$cross_compile,
+	'module|m=s'	=> \$modulefile,
+	'help|h'		=> \&usage,
+);
+my $vmlinux_name = $ARGV[$#ARGV];
 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
-#
+
+# Parse the oops to find the EIP value
 
 my $target = "0";
 my $function;
@@ -177,26 +187,26 @@ sub process_x86_regs
 my $decodestop = Math::BigInt->from_hex("0x$target") + 8192;
 if ($target eq "0") {
 	print "No oops found!\n";
-	print "Usage: \n";
-	print "    dmesg | perl scripts/markup_oops.pl vmlinux\n";
-	exit;
+	usage();
 }
 
 # if it's a module, we need to find the .ko file and calculate a load offset
 if ($module ne "") {
-	my $modulefile = `modinfo $module | grep '^filename:' | awk '{ print \$2 }'`;
-	chomp($modulefile);
+	if ($modulefile eq "") {
+		my $modulefile = `modinfo $module | grep '^filename:' | awk '{ print \$2 }'`;
+		chomp($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";
+	open(FILE, $cross_compile."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);
+			$vmaoffset = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$fu") - Math::BigInt->from_hex("0x$func_offset");
 		}
 	}
 	close(FILE);
@@ -212,7 +222,7 @@ sub InRange {
 	my ($address, $target) = @_;
 	my $ad = "0x".$address;
 	my $ta = "0x".$target;
-	my $delta = hex($ad) - hex($ta);
+	my $delta = Math::BigInt->from_hex($ad) - Math::BigInt->from_hex($ta);
 
 	if (($delta > -4096) && ($delta < 4096)) {
 		return 1;
@@ -225,7 +235,7 @@ 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
 
-open(FILE, "objdump -dS --adjust-vma=$vmaoffset --start-address=$decodestart --stop-address=$decodestop $filename |") || die "Cannot start objdump";
+open(FILE, $cross_compile."objdump -dS --adjust-vma=$vmaoffset --start-address=$decodestart --stop-address=$decodestop $filename |") || die "Cannot start objdump";
 
 while (<FILE>) {
 	my $line = $_;
@@ -345,3 +355,16 @@ sub InRange {
 	$i = $i +1;
 }
 
+sub usage {
+	print <<EOT;
+Usage:
+  dmesg | perl $0 [OPTION] [VMLINUX]
+
+OPTION:
+  -c, --cross-compile CROSS_COMPILE	Specify the prefix used for toolchain.
+  -m, --module MODULE_DIRNAME		Specify the module directory name.
+  -h, --help				Help.
+EOT
+	exit;
+}
+