source: MondoRescue/branches/2.2.5/mindi-busybox/scripts/checkstack.pl @ 1765

#!/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 eq 'blackfin') {
        #      52:       00 e8 03 00     LINK 0xc;
        $re = qr/.*LINK (0x$x{1,5});$/o;
    } elsif ($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;