#!/usr/bin/env perl
# SPDX-License-Identifier: GPL-2.0
# Check the stack usage of functions
#
# Copyright Joern Engel <joern@lazybastard.org>
# 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
# Random bits by Matt Mackall <mpm@selenic.com>
# M68k port by Geert Uytterhoeven and Andreas Schwab
# AArch64, PARISC ports by Kyle McMartin
# sparc port by Martin Habets <errandir_news@mph.eclipse.co.uk>
# ppc64le port by Breno Leitao <leitao@debian.org>
# riscv port by Wadim Mueller <wafgo01@gmail.com>
#
# Usage:
# objdump -d vmlinux | scripts/checkstack.pl [arch]
#
# TODO : Port to all architectures (one regex per arch)
use strict;
# 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
#
# $dre is similar, but for dynamic stack redutions:
# $& (whole re) matches the complete objdump line with the stack growth
# $1 (first bracket) matches the dynamic amount of the stack growth
#
# $sub: subroutine for special handling to check stack usage.
#
# use anything else and feel the pain ;)
my (@stack, $re, $dre, $sub, $x, $xs, $funcre, $min_stack);
{
my $arch = shift;
if ($arch eq "") {
$arch = `uname -m`;
chomp($arch);
}
$min_stack = shift;
if ($min_stack eq "" || $min_stack !~ /^\d+$/) {
$min_stack = 100;
}
$x = "[0-9a-f]"; # hex character
$xs = "[0-9a-f ]"; # hex character or space
$funcre = qr/^$x* <(.*)>:$/;
if ($arch =~ '^(aarch|arm)64$') {
#ffffffc0006325cc: a9bb7bfd stp x29, x30, [sp, #-80]!
#a110: d11643ff sub sp, sp, #0x590
$re = qr/^.*stp.*sp, \#-([0-9]{1,8})\]\!/o;
$dre = qr/^.*sub.*sp, sp, #(0x$x{1,8})/o;
} elsif ($arch eq 'arm') {
#c0008ffc: e24dd064 sub sp, sp, #100 ; 0x64
$re = qr/.*sub.*sp, sp, #([0-9]{1,4})/o;
$sub = \&arm_push_handling;
} elsif ($arch =~ /^x86(_64)?$/ || $arch =~ /^i[3456]86$/) {
#c0105234: 81 ec ac 05 00 00 sub $0x5ac,%esp
# or
# 2f60: 48 81 ec e8 05 00 00 sub $0x5e8,%rsp
$re = qr/^.*[as][du][db] \$(0x$x{1,8}),\%(e|r)sp$/o;
$dre = qr/^.*[as][du][db] (%.*),\%(e|r)sp$/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 'nios2') {
#25a8: defffb04 addi sp,sp,-20
$re = qr/.*addi.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
} elsif ($arch eq 'openrisc') {
# c000043c: 9c 21 fe f0 l.addi r1,r1,-272
$re = qr/.*l\.addi.*r1,r1,-(([0-9]{2}|[3-9])[0-9]{2})/o;
} elsif ($arch eq 'parisc' || $arch eq 'parisc64') {
$re = qr/.*ldo ($x{1,8})\(sp\),sp/o;
} elsif ($arch eq 'powerpc' || $arch =~ /^ppc(64)?(le)?$/ ) {
# powerpc : 94 21 ff 30 stwu r1,-208(r1)
# ppc64(le) : 81 ff 21 f8 stdu r1,-128(r1)
$re = qr/.*st[dw]u.*r1,-($x{1,8})\(r1\)/o;
} elsif ($arch =~ /^s390x?$/) {
# 11160: a7 fb ff 60 aghi %r15,-160
# or
# 100092: e3 f0 ff c8 ff 71 lay %r15,-56(%r15)
$re = qr/.*(?:lay|ag?hi).*\%r15,-(([0-9]{2}|[3-9])[0-9]{2})
(?:\(\%r15\))?$/ox;
} elsif ($arch eq 'sparc' || $arch eq 'sparc64') {
# f0019d10: 9d e3 bf 90 save %sp, -112, %sp
$re = qr/.*save.*%sp, -(([0-9]{2}|[3-9])[0-9]{2}), %sp/o;
} elsif ($arch =~ /^riscv(64)?$/) {
#ffffffff8036e868: c2010113 addi sp,sp,-992
$re = qr/.*addi.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
} else {
print("wrong or unknown architecture \"$arch\"\n");
exit
}
}
#
# To count stack usage of push {*, fp, ip, lr, pc} instruction in ARM,
# if FRAME POINTER is enabled.
# e.g. c01f0d48: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc}
#
sub arm_push_handling {
my $regex = qr/.*push.*fp, ip, lr, pc}/o;
my $size = 0;
my $line_arg = shift;
if ($line_arg =~ m/$regex/) {
$size = $line_arg =~ tr/,//;
$size = ($size + 1) * 4;
}
return $size;
}
#
# main()
#
my ($func, $file, $lastslash, $total_size, $addr, $intro);
$total_size = 0;
while (my $line = <STDIN>) {
if ($line =~ m/$funcre/) {
$func = $1;
next if $line !~ m/^($xs*)/;
if ($total_size > $min_stack) {
push @stack, "$intro$total_size\n";
}
$addr = $1;
$addr =~ s/ /0/g;
$addr = "0x$addr";
$intro = "$addr $func [$file]:";
my $padlen = 56 - length($intro);
while ($padlen > 0) {
$intro .= ' ';
$padlen -= 8;
}
$total_size = 0;
}
elsif ($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);
$total_size += $size;
}
elsif (defined $dre && $line =~ m/$dre/) {
my $size = $1;
$size = hex($size) if ($size =~ /^0x/);
$total_size += $size;
}
elsif (defined $sub) {
my $size = &$sub($line);
$total_size += $size;
}
}
if ($total_size > $min_stack) {
push @stack, "$intro$total_size\n";
}
# Sort output by size (last field)
print sort { ($b =~ /:\t*(\d+)$/)[0] <=> ($a =~ /:\t*(\d+)$/)[0] } @stack;
