xref: /linux/scripts/checkstack.pl (revision 45d8b572fac3aa8b49d53c946b3685eaf78a2824) 
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#	Arm port by Holger Schurig
12#	Random bits by Matt Mackall <mpm@selenic.com>
13#	M68k port by Geert Uytterhoeven and Andreas Schwab
14#	AArch64, PARISC ports by Kyle McMartin
15#	sparc port by Martin Habets <errandir_news@mph.eclipse.co.uk>
16#	ppc64le port by Breno Leitao <leitao@debian.org>
17#	riscv port by Wadim Mueller <wafgo01@gmail.com>
18#	loongarch port by Youling Tang <tangyouling@kylinos.cn>
19#
20#	Usage:
21#	objdump -d vmlinux | scripts/checkstack.pl [arch] [min_stack]
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 = 512;
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 'm68k') {
72		#    2b6c:       4e56 fb70       linkw %fp,#-1168
73		#  1df770:       defc ffe4       addaw #-28,%sp
74		$re = qr/.*(?:linkw %fp,|addaw )#-([0-9]{1,4})(?:,%sp)?$/o;
75	} elsif ($arch eq 'mips64') {
76		#8800402c:       67bdfff0        daddiu  sp,sp,-16
77		$re = qr/.*daddiu.*sp,sp,-([0-9]{1,8})/o;
78	} elsif ($arch eq 'mips') {
79		#88003254:       27bdffe0        addiu   sp,sp,-32
80		$re = qr/.*addiu.*sp,sp,-([0-9]{1,8})/o;
81	} elsif ($arch eq 'nios2') {
82		#25a8:	defffb04 	addi	sp,sp,-20
83		$re = qr/.*addi.*sp,sp,-([0-9]{1,8})/o;
84	} elsif ($arch eq 'openrisc') {
85		# c000043c:       9c 21 fe f0     l.addi r1,r1,-272
86		$re = qr/.*l\.addi.*r1,r1,-([0-9]{1,8})/o;
87	} elsif ($arch eq 'parisc' || $arch eq 'parisc64') {
88		$re = qr/.*ldo ($x{1,8})\(sp\),sp/o;
89	} elsif ($arch eq 'powerpc' || $arch =~ /^ppc(64)?(le)?$/ ) {
90		# powerpc    : 94 21 ff 30     stwu    r1,-208(r1)
91		# ppc64(le)  : 81 ff 21 f8     stdu    r1,-128(r1)
92		$re = qr/.*st[dw]u.*r1,-($x{1,8})\(r1\)/o;
93	} elsif ($arch =~ /^s390x?$/) {
94		#   11160:       a7 fb ff 60             aghi   %r15,-160
95		# or
96		#  100092:	 e3 f0 ff c8 ff 71	 lay	 %r15,-56(%r15)
97		$re = qr/.*(?:lay|ag?hi).*\%r15,-([0-9]+)(?:\(\%r15\))?$/o;
98	} elsif ($arch eq 'sparc' || $arch eq 'sparc64') {
99		# f0019d10:       9d e3 bf 90     save  %sp, -112, %sp
100		$re = qr/.*save.*%sp, -([0-9]{1,8}), %sp/o;
101	} elsif ($arch =~ /^riscv(64)?$/) {
102		#ffffffff8036e868:	c2010113          	addi	sp,sp,-992
103		$re = qr/.*addi.*sp,sp,-([0-9]{1,8})/o;
104	} elsif ($arch =~ /^loongarch(32|64)?$/) {
105		#9000000000224708:	02ff4063		addi.d  $sp, $sp, -48(0xfd0)
106		$re = qr/.*addi\..*sp, .*sp, -([0-9]{1,8}).*/o;
107	} else {
108		print("wrong or unknown architecture \"$arch\"\n");
109		exit
110	}
111}
112
113#
114# To count stack usage of push {*, fp, ip, lr, pc} instruction in ARM,
115# if FRAME POINTER is enabled.
116# e.g. c01f0d48: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc}
117#
118sub arm_push_handling {
119	my $regex = qr/.*push.*fp, ip, lr, pc}/o;
120	my $size = 0;
121	my $line_arg = shift;
122
123	if ($line_arg =~ m/$regex/) {
124		$size = $line_arg =~ tr/,//;
125		$size = ($size + 1) * 4;
126	}
127
128	return $size;
129}
130
131#
132# main()
133#
134my ($func, $file, $lastslash, $total_size, $addr, $intro);
135
136$total_size = 0;
137
138while (my $line = <STDIN>) {
139	if ($line =~ m/$funcre/) {
140		$func = $1;
141		next if $line !~ m/^($x*)/;
142		if ($total_size > $min_stack) {
143			push @stack, "$intro$total_size\n";
144		}
145		$addr = "0x$1";
146		$intro = "$addr $func [$file]:";
147		my $padlen = 56 - length($intro);
148		while ($padlen > 0) {
149			$intro .= '	';
150			$padlen -= 8;
151		}
152
153		$total_size = 0;
154	}
155	elsif ($line =~ m/(.*):\s*file format/) {
156		$file = $1;
157		$file =~ s/\.ko//;
158		$lastslash = rindex($file, "/");
159		if ($lastslash != -1) {
160			$file = substr($file, $lastslash + 1);
161		}
162	}
163	elsif ($line =~ m/$re/) {
164		my $size = $1;
165		$size = hex($size) if ($size =~ /^0x/);
166
167		if ($size > 0xf0000000) {
168			$size = - $size;
169			$size += 0x80000000;
170			$size += 0x80000000;
171		}
172		next if ($size > 0x10000000);
173
174		$total_size += $size;
175	}
176	elsif (defined $dre && $line =~ m/$dre/) {
177		my $size = $1;
178
179		$size = hex($size) if ($size =~ /^0x/);
180		$total_size += $size;
181	}
182	elsif (defined $sub) {
183		my $size = &$sub($line);
184
185		$total_size += $size;
186	}
187}
188if ($total_size > $min_stack) {
189	push @stack, "$intro$total_size\n";
190}
191
192# Sort output by size (last field) and function name if size is the same
193sub sort_lines {
194	my ($a, $b) = @_;
195
196	my $num_a = $1 if $a =~ /:\t*(\d+)$/;
197	my $num_b = $1 if $b =~ /:\t*(\d+)$/;
198	my $func_a = $1 if $a =~ / (.*):/;
199	my $func_b = $1 if $b =~ / (.*):/;
200
201	if ($num_a != $num_b) {
202		return $num_b <=> $num_a;
203	} else {
204		return $func_a cmp $func_b;
205	}
206}
207
208print sort { sort_lines($a, $b) } @stack;
209