LXR linux/scripts/checkstack.pl

   1#!/usr/bin/env perl
   2# SPDX-License-Identifier: GPL-2.0
   3
   4#       Check the stack usage of functions
   5#
   6#       Copyright Joern Engel <joern@lazybastard.org>
   7#       Inspired by Linus Torvalds
   8#       Original idea maybe from Keith Owens
   9#       s390 port and big speedup by Arnd Bergmann <arnd@bergmann-dalldorf.de>
  10#       Mips port by Juan Quintela <quintela@mandrakesoft.com>
  11#       IA64 port via Andreas Dilger
  12#       Arm port by Holger Schurig
  13#       sh64 port by Paul Mundt
  14#       Random bits by Matt Mackall <mpm@selenic.com>
  15#       M68k port by Geert Uytterhoeven and Andreas Schwab
  16#       AArch64, PARISC ports by Kyle McMartin
  17#       sparc port by Martin Habets <errandir_news@mph.eclipse.co.uk>
  18#       ppc64le port by Breno Leitao <leitao@debian.org>
  19#
  20#       Usage:
  21#       objdump -d vmlinux | scripts/checkstack.pl [arch]
  22#
  23#       TODO :  Port to all architectures (one regex per arch)
  24
  25use strict;
  26
  27# check for arch
  28#
  29# $re is used for two matches:
  30# $& (whole re) matches the complete objdump line with the stack growth
  31# $1 (first bracket) matches the size of the stack growth
  32#
  33# $dre is similar, but for dynamic stack redutions:
  34# $& (whole re) matches the complete objdump line with the stack growth
  35# $1 (first bracket) matches the dynamic amount of the stack growth
  36#
  37# $sub: subroutine for special handling to check stack usage.
  38#
  39# use anything else and feel the pain ;)
  40my (@stack, $re, $dre, $sub, $x, $xs, $funcre, $min_stack);
  41{
  42        my $arch = shift;
  43        if ($arch eq "") {
  44                $arch = `uname -m`;
  45                chomp($arch);
  46        }
  47
  48        $min_stack = shift;
  49        if ($min_stack eq "" || $min_stack !~ /^\d+$/) {
  50                $min_stack = 100;
  51        }
  52
  53        $x      = "[0-9a-f]";   # hex character
  54        $xs     = "[0-9a-f ]";  # hex character or space
  55        $funcre = qr/^$x* <(.*)>:$/;
  56        if ($arch =~ '^(aarch|arm)64$') {
  57                #ffffffc0006325cc:       a9bb7bfd        stp     x29, x30, [sp, #-80]!
  58                #a110:       d11643ff        sub     sp, sp, #0x590
  59                $re = qr/^.*stp.*sp, \#-([0-9]{1,8})\]\!/o;
  60                $dre = qr/^.*sub.*sp, sp, #(0x$x{1,8})/o;
  61        } elsif ($arch eq 'arm') {
  62                #c0008ffc:      e24dd064        sub     sp, sp, #100    ; 0x64
  63                $re = qr/.*sub.*sp, sp, #([0-9]{1,4})/o;
  64                $sub = \&arm_push_handling;
  65        } elsif ($arch =~ /^x86(_64)?$/ || $arch =~ /^i[3456]86$/) {
  66                #c0105234:       81 ec ac 05 00 00       sub    $0x5ac,%esp
  67                # or
  68                #    2f60:    48 81 ec e8 05 00 00       sub    $0x5e8,%rsp
  69                $re = qr/^.*[as][du][db]    \$(0x$x{1,8}),\%(e|r)sp$/o;
  70                $dre = qr/^.*[as][du][db]    (%.*),\%(e|r)sp$/o;
  71        } elsif ($arch eq 'ia64') {
  72                #e0000000044011fc:       01 0f fc 8c     adds r12=-384,r12
  73                $re = qr/.*adds.*r12=-(([0-9]{2}|[3-9])[0-9]{2}),r12/o;
  74        } elsif ($arch eq 'm68k') {
  75                #    2b6c:       4e56 fb70       linkw %fp,#-1168
  76                #  1df770:       defc ffe4       addaw #-28,%sp
  77                $re = qr/.*(?:linkw %fp,|addaw )#-([0-9]{1,4})(?:,%sp)?$/o;
  78        } elsif ($arch eq 'mips64') {
  79                #8800402c:       67bdfff0        daddiu  sp,sp,-16
  80                $re = qr/.*daddiu.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
  81        } elsif ($arch eq 'mips') {
  82                #88003254:       27bdffe0        addiu   sp,sp,-32
  83                $re = qr/.*addiu.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
  84        } elsif ($arch eq 'nios2') {
  85                #25a8:  defffb04        addi    sp,sp,-20
  86                $re = qr/.*addi.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
  87        } elsif ($arch eq 'openrisc') {
  88                # c000043c:       9c 21 fe f0     l.addi r1,r1,-272
  89                $re = qr/.*l\.addi.*r1,r1,-(([0-9]{2}|[3-9])[0-9]{2})/o;
  90        } elsif ($arch eq 'parisc' || $arch eq 'parisc64') {
  91                $re = qr/.*ldo ($x{1,8})\(sp\),sp/o;
  92        } elsif ($arch eq 'powerpc' || $arch =~ /^ppc(64)?(le)?$/ ) {
  93                # powerpc    : 94 21 ff 30     stwu    r1,-208(r1)
  94                # ppc64(le)  : 81 ff 21 f8     stdu    r1,-128(r1)
  95                $re = qr/.*st[dw]u.*r1,-($x{1,8})\(r1\)/o;
  96        } elsif ($arch =~ /^s390x?$/) {
  97                #   11160:       a7 fb ff 60             aghi   %r15,-160
  98                # or
  99                #  100092:       e3 f0 ff c8 ff 71       lay     %r15,-56(%r15)
 100                $re = qr/.*(?:lay|ag?hi).*\%r15,-(([0-9]{2}|[3-9])[0-9]{2})
 101                      (?:\(\%r15\))?$/ox;
 102        } elsif ($arch =~ /^sh64$/) {
 103                #XXX: we only check for the immediate case presently,
 104                #     though we will want to check for the movi/sub
 105                #     pair for larger users. -- PFM.
 106                #a00048e0:       d4fc40f0        addi.l  r15,-240,r15
 107                $re = qr/.*addi\.l.*r15,-(([0-9]{2}|[3-9])[0-9]{2}),r15/o;
 108        } elsif ($arch eq 'sparc' || $arch eq 'sparc64') {
 109                # f0019d10:       9d e3 bf 90     save  %sp, -112, %sp
 110                $re = qr/.*save.*%sp, -(([0-9]{2}|[3-9])[0-9]{2}), %sp/o;
 111        } else {
 112                print("wrong or unknown architecture \"$arch\"\n");
 113                exit
 114        }
 115}
 116
 117#
 118# To count stack usage of push {*, fp, ip, lr, pc} instruction in ARM,
 119# if FRAME POINTER is enabled.
 120# e.g. c01f0d48: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc}
 121#
 122sub arm_push_handling {
 123        my $regex = qr/.*push.*fp, ip, lr, pc}/o;
 124        my $size = 0;
 125        my $line_arg = shift;
 126
 127        if ($line_arg =~ m/$regex/) {
 128                $size = $line_arg =~ tr/,//;
 129                $size = ($size + 1) * 4;
 130        }
 131
 132        return $size;
 133}
 134
 135#
 136# main()
 137#
 138my ($func, $file, $lastslash, $total_size, $addr, $intro);
 139
 140$total_size = 0;
 141
 142while (my $line = <STDIN>) {
 143        if ($line =~ m/$funcre/) {
 144                $func = $1;
 145                next if $line !~ m/^($xs*)/;
 146                if ($total_size > $min_stack) {
 147                        push @stack, "$intro$total_size\n";
 148                }
 149
 150                $addr = $1;
 151                $addr =~ s/ /0/g;
 152                $addr = "0x$addr";
 153
 154                $intro = "$addr $func [$file]:";
 155                my $padlen = 56 - length($intro);
 156                while ($padlen > 0) {
 157                        $intro .= '     ';
 158                        $padlen -= 8;
 159                }
 160
 161                $total_size = 0;
 162        }
 163        elsif ($line =~ m/(.*):\s*file format/) {
 164                $file = $1;
 165                $file =~ s/\.ko//;
 166                $lastslash = rindex($file, "/");
 167                if ($lastslash != -1) {
 168                        $file = substr($file, $lastslash + 1);
 169                }
 170        }
 171        elsif ($line =~ m/$re/) {
 172                my $size = $1;
 173                $size = hex($size) if ($size =~ /^0x/);
 174
 175                if ($size > 0xf0000000) {
 176                        $size = - $size;
 177                        $size += 0x80000000;
 178                        $size += 0x80000000;
 179                }
 180                next if ($size > 0x10000000);
 181
 182                $total_size += $size;
 183        }
 184        elsif (defined $dre && $line =~ m/$dre/) {
 185                my $size = $1;
 186
 187                $size = hex($size) if ($size =~ /^0x/);
 188                $total_size += $size;
 189        }
 190        elsif (defined $sub) {
 191                my $size = &$sub($line);
 192
 193                $total_size += $size;
 194        }
 195}
 196if ($total_size > $min_stack) {
 197        push @stack, "$intro$total_size\n";
 198}
 199
 200# Sort output by size (last field)
 201print sort { ($b =~ /:\t*(\d+)$/)[0] <=> ($a =~ /:\t*(\d+)$/)[0] } @stack;
 202