xref: /linux/scripts/checkstack.pl (revision cbafa54aa2ae23939846e150ad4ba98c784f6395) 
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