Re: [PATCH] add checkstack Makefile target

["Jörn Engel" <joern@wohnheim.fh-wedel.de>]

Added Keith to cc

On Tue, 4 March 2003 08:24:43 +0100, Jörn Engel wrote:
> On Tue, 4 March 2003 09:03:04 +0200, Muli Ben-Yehuda wrote:
> > 
> > Keith Owens has such a script, and even posted it here a time or
> > three. You can find it (and various other near scripts) at
> > http://www.kernelnewbies.org/scripts/.
> 
> Good point!
> Comparing both, there are some points in my favor though:
> - Works for ppc as well, other platforms should be simple.
> - Works for cross-compiling out of the box.
> - More readable. :)
- Linus output is nicer.

Con:
- Keith is _much_ faster. 14s vs. 200s on some test kernel.

Tough call. How much does speed matter for something like this?

Still, the patch was updated a little.

Jörn

-- 
Geld macht nicht glücklich.
Glück macht nicht satt.

diff -Naur foo/linux-2.4.20/arch/i386/Makefile linux-2.4.20/arch/i386/Makefile
--- foo/linux-2.4.20/arch/i386/Makefile	Fri Nov 29 00:53:09 2002
+++ linux-2.4.20/arch/i386/Makefile	Mon Mar  3 21:38:36 2003
@@ -139,9 +139,18 @@
 	@$(MAKEBOOT) BOOTIMAGE=bzImage install
 
 archclean:
+	$(RM) $(TOPDIR)/scripts/checkstack_i386.pl
 	@$(MAKEBOOT) clean
 
 archmrproper:
 
 archdep:
 	@$(MAKEBOOT) dep
+
+$(TOPDIR)/scripts/checkstack_i386.pl: $(TOPDIR)/scripts/checkstack.pl
+	(cd $(TOPDIR)/scripts/ && ln -s checkstack.pl checkstack_i386.pl)
+
+checkstack: vmlinux $(TOPDIR)/scripts/checkstack_i386.pl
+	$(OBJDUMP) -d vmlinux | \
+	grep 'sub.*$0x...,.*esp' | \
+	$(TOPDIR)/scripts/checkstack_i386.pl
diff -Naur foo/linux-2.4.20/arch/ppc/Makefile linux-2.4.20/arch/ppc/Makefile
--- foo/linux-2.4.20/arch/ppc/Makefile	Fri Nov 29 00:53:11 2002
+++ linux-2.4.20/arch/ppc/Makefile	Mon Mar  3 21:38:52 2003
@@ -108,6 +108,7 @@
 	cp -f arch/ppc/configs/$(@:config=defconfig) arch/ppc/defconfig
 
 archclean:
+	$(RM) $(TOPDIR)/scripts/checkstack_ppc.pl
 	rm -f arch/ppc/kernel/{mk_defs,ppc_defs.h,find_name,checks}
 	@$(MAKEBOOT) clean
 
@@ -115,3 +116,11 @@
 
 archdep: scripts/mkdep
 	$(MAKEBOOT) fastdep
+
+$(TOPDIR)/scripts/checkstack_ppc.pl: $(TOPDIR)/scripts/checkstack.pl
+	(cd $(TOPDIR)/scripts/ && ln -s checkstack.pl checkstack_ppc.pl)
+
+checkstack: vmlinux $(TOPDIR)/scripts/checkstack_ppc.pl
+	$(OBJDUMP) -d vmlinux | \
+	grep 'stwu.*r1,-.\{3,\}(r1)' | \
+	$(TOPDIR)/scripts/checkstack_ppc.pl
diff -Naur foo/linux-2.4.20/scripts/checkstack.pl linux-2.4.20/scripts/checkstack.pl
--- foo/linux-2.4.20/scripts/checkstack.pl	Thu Jan  1 01:00:00 1970
+++ linux-2.4.20/scripts/checkstack.pl	Tue Mar  4 11:07:23 2003
@@ -0,0 +1,105 @@
+#!/usr/bin/perl
+
+#	Check the stack usage of functions
+#
+#	Copyright Joern Engel <joern@wh.fh-wedel.de>
+#	Inspired by Linus Torvalds
+#	Original idea maybe from Keith Owens
+#
+#	Usage for ppc:
+#	ln -s stackcheck.pl stackcheck_ppc.pl
+#	powerpc-linux-objdump -d vmlinux | \
+#	grep 'stwu.*r1,-.\{3,\}(r1)' | \
+#	stackcheck_ppc.pl
+
+# check for arch
+{
+	(my $arch = $0) =~ s/.*checkstack_(.+)\.pl$/\1/;
+	if ($arch =~ /^i386$/) {
+		$get_code = 'get_code_i386 "@_"';
+		$bysize = 'bysize_i386 "@_"';
+	} elsif ($arch =~ /^ppc$/) {
+		$get_code = 'get_code_ppc "@_"';
+		$bysize = 'bysize_ppc "@_"';
+	} else {
+		print "wrong or unknown architecture";
+		exit
+	}
+}
+
+# arch-independent: address and function name
+sub get_intro($) {
+	my $line = $_[0];
+
+	(my $addr = $line) =~ s/^([0-9a-f]{8}).*/0x\1/;
+	chomp($addr);
+
+	my $ksymoops = `ksymoops -v vmlinux -m System.map -K -L -O -A $addr | \
+			tail -2 | head -1`;
+	(my $func = $ksymoops) =~ s/^Adhoc [0-9a-f]{8} (<.*>)/\1/;
+	chomp($func);
+
+	my $intro = "$addr $func:";
+	my $padlen = 56 - length($intro);
+	while ($padlen > 0) {
+		$intro .= '	';
+		$padlen -= 8;
+	}
+	return $intro
+}
+
+# arch-specific: code and comparison
+
+#c00029f4:       94 21 ff 30     stwu    r1,-208(r1)
+sub get_code_ppc {
+	(my $code = shift) =~ s/.*(stwu.*)/\1/;
+	chomp($code);
+	return $code
+}
+
+sub bysize_ppc {
+	($asize = $a) =~ s/.*r1,-([0-9]+)\(r1\)/\1/;
+	($bsize = $b) =~ s/.*r1,-([0-9]+)\(r1\)/\1/;
+	$bsize <=> $asize 
+}
+
+#c0105234:       81 ec ac 05 00 00       sub    $0x5ac,%esp
+sub get_code_i386 {
+	(my $code = shift) =~ s/.*(sub.*)/\1/;
+	chomp($code);
+	return $code
+}
+
+sub bysize_i386 {
+	($asize = $a) =~ s/.*sub.*\$0x([0-9]+),\%esp/\1/;
+	($bsize = $b) =~ s/.*sub.*\$0x([0-9]+),\%esp/\1/;
+	$a cmp $b
+}
+
+sub get_code($) {
+	eval $get_code
+}
+
+sub bysize($) {
+	eval $bysize
+}
+
+#
+# main()
+#
+$i = 5;
+while (defined($line = <STDIN>)
+	#&& $i-- > 0
+	) {
+
+	my $intro = get_intro($line);
+	my $code = get_code($line);
+
+	$stack[@stack] = "$intro $code";
+}
+
+@sortedstack = sort bysize @stack;
+
+foreach $i (@sortedstack) {
+	print("$i\n");
+}