#!/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
  #	sh64 port by Paul Mundt
  #	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>

  #
  #	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 ($arch =~ /^sh64$/) {
  		#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;

  	} 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;

  	} else {

  		print("wrong or unknown architecture \"$arch\"
  ");

  		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
  ";
  		}
  
  		$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
  ";
  }

  # Sort output by size (last field)
  print sort { ($b =~ /:\t*(\d+)$/)[0] <=> ($a =~ /:\t*(\d+)$/)[0] } @stack;