add script which measures stack consumption.

Current top users:

0x08052f52 uncompress []:                               393312
0x080c8a58 input_tab []:                                82104
0x08092d5b ifaddrlist []:                               32828
0x08056163 loadfont_main []:                            32796
0x0806e508 colon []:                                    16532
0x08056095 do_loadfont []:                              16400
0x0806da70 place_cursor []:                             16388
0x080792e8 login_main []:                               9176

393 kb of stack??? OMG...

Makefile.custom

@@ -79,9 +79,13 @@ baseline: busybox_unstripped
 objsizes: busybox_unstripped
 	$(srctree)/scripts/objsizes
 
+.PHONY: stksizes
+stksizes: busybox_unstripped
+	$(CROSS_COMPILE)objdump -d busybox_unstripped | $(srctree)/scripts/checkstack.pl $(ARCH)
+
 .PHONY: bigdata
 bigdata: busybox_unstripped
-	nm --size-sort busybox_unstripped | grep -vi ' [tr] ' | tail -20
+	$(CROSS_COMPILE)nm --size-sort busybox_unstripped | grep -vi ' [tr] '
 
 # Documentation Targets
 .PHONY: doc

Makefile.help

@@ -39,4 +39,6 @@ help:
 	@echo '  release		- create a distribution tarball'
 	@echo '  sizes			- show size of all enabled busybox symbols'
 	@echo '  objsizes		- show size of each .o object built'
+	@echo '  bigdata		- show data objects, biggest first'
+	@echo '  stksizes		- show stack users, biggest first'
 	@echo

scripts/checkstack.pl

@@ -0,0 +1,137 @@
+#!/usr/bin/perl
+
+# Stolen from Linux kernel :)
+
+#	Check the stack usage of functions
+#
+#	Copyright Joern Engel <joern@wh.fh-wedel.de>
+#	Inspired by Linus Torvalds
+#	Original idea maybe from Keith Owens
+#	s390 port and big speedup by Arnd Bergmann <arnd@bergmann-dalldorf.de>
+#	Mips port by Juan Quintela <quintela@mandrakesoft.com>
+#	IA64 port via Andreas Dilger
+#	Arm port by Holger Schurig
+#	sh64 port by Paul Mundt
+#	Random bits by Matt Mackall <mpm@selenic.com>
+#	M68k port by Geert Uytterhoeven and Andreas Schwab
+#
+#	Usage:
+#	objdump -d vmlinux | checkstack.pl [arch]
+#
+#	TODO :	Port to all architectures (one regex per arch)
+
+# check for arch
+#
+# $re is used for two matches:
+# $& (whole re) matches the complete objdump line with the stack growth
+# $1 (first bracket) matches the size of the stack growth
+#
+# use anything else and feel the pain ;)
+my (@stack, $re, $x, $xs);
+{
+	my $arch = shift;
+	if ($arch eq "") {
+		$arch = `uname -m`;
+	}
+
+	$x	= "[0-9a-f]";	# hex character
+	$xs	= "[0-9a-f ]";	# hex character or space
+	if ($arch eq 'arm') {
+		#c0008ffc:	e24dd064	sub	sp, sp, #100	; 0x64
+		$re = qr/.*sub.*sp, sp, #(([0-9]{2}|[3-9])[0-9]{2})/o;
+	} elsif ($arch =~ /^i[3456]86$/) {
+		#c0105234:       81 ec ac 05 00 00       sub    $0x5ac,%esp
+		$re = qr/^.*[as][du][db]    \$(0x$x{1,8}),\%esp$/o;
+	} elsif ($arch eq 'x86_64') {
+		#    2f60:	48 81 ec e8 05 00 00 	sub    $0x5e8,%rsp
+		$re = qr/^.*[as][du][db]    \$(0x$x{1,8}),\%rsp$/o;
+	} elsif ($arch eq 'ia64') {
+		#e0000000044011fc:       01 0f fc 8c     adds r12=-384,r12
+		$re = qr/.*adds.*r12=-(([0-9]{2}|[3-9])[0-9]{2}),r12/o;
+	} elsif ($arch eq 'm68k') {
+		#    2b6c:       4e56 fb70       linkw %fp,#-1168
+		#  1df770:       defc ffe4       addaw #-28,%sp
+		$re = qr/.*(?:linkw %fp,|addaw )#-([0-9]{1,4})(?:,%sp)?$/o;
+	} elsif ($arch eq 'mips64') {
+		#8800402c:       67bdfff0        daddiu  sp,sp,-16
+		$re = qr/.*daddiu.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
+	} elsif ($arch eq 'mips') {
+		#88003254:       27bdffe0        addiu   sp,sp,-32
+		$re = qr/.*addiu.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
+	} elsif ($arch eq 'ppc') {
+		#c00029f4:       94 21 ff 30     stwu    r1,-208(r1)
+		$re = qr/.*stwu.*r1,-($x{1,8})\(r1\)/o;
+	} elsif ($arch eq 'ppc64') {
+		#XXX
+		$re = qr/.*stdu.*r1,-($x{1,8})\(r1\)/o;
+	} elsif ($arch eq 'powerpc') {
+		$re = qr/.*st[dw]u.*r1,-($x{1,8})\(r1\)/o;
+	} elsif ($arch =~ /^s390x?$/) {
+		#   11160:       a7 fb ff 60             aghi   %r15,-160
+		$re = qr/.*ag?hi.*\%r15,-(([0-9]{2}|[3-9])[0-9]{2})/o;
+	} elsif ($arch =~ /^sh64$/) {
+		#XXX: we only check for the immediate case presently,
+		#     though we will want to check for the movi/sub
+		#     pair for larger users. -- PFM.
+		#a00048e0:       d4fc40f0        addi.l  r15,-240,r15
+		$re = qr/.*addi\.l.*r15,-(([0-9]{2}|[3-9])[0-9]{2}),r15/o;
+	} else {
+		print("wrong or unknown architecture\n");
+		exit
+	}
+}
+
+sub bysize($) {
+	my ($asize, $bsize);
+	($asize = $a) =~ s/.*:	*(.*)$/$1/;
+	($bsize = $b) =~ s/.*:	*(.*)$/$1/;
+	$bsize <=> $asize
+}
+
+#
+# main()
+#
+my $funcre = qr/^$x* <(.*)>:$/;
+my $func;
+my $file, $lastslash;
+
+while (my $line = <STDIN>) {
+	if ($line =~ m/$funcre/) {
+		$func = $1;
+	}
+	elsif ($line =~ m/(.*):\s*file format/) {
+		$file = $1;
+		$file =~ s/\.ko//;
+		$lastslash = rindex($file, "/");
+		if ($lastslash != -1) {
+			$file = substr($file, $lastslash + 1);
+		}
+	}
+	elsif ($line =~ m/$re/) {
+		my $size = $1;
+		$size = hex($size) if ($size =~ /^0x/);
+
+		if ($size > 0xf0000000) {
+			$size = - $size;
+			$size += 0x80000000;
+			$size += 0x80000000;
+		}
+		next if ($size > 0x10000000);
+
+		next if $line !~ m/^($xs*)/;
+		my $addr = $1;
+		$addr =~ s/ /0/g;
+		$addr = "0x$addr";
+
+		my $intro = "$addr $func [$file]:";
+		my $padlen = 56 - length($intro);
+		while ($padlen > 0) {
+			$intro .= '	';
+			$padlen -= 8;
+		}
+		next if ($size < 100);
+		push @stack, "$intro$size\n";
+	}
+}
+
+print sort bysize @stack;