xref: /linux/scripts/checkstack.pl (revision bf80eef2212a1e8451df13b52533f4bc31bb4f8e) 
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#	riscv port by Wadim Mueller <wafgo01@gmail.com>
20#
21#	Usage:
22#	objdump -d vmlinux | scripts/checkstack.pl [arch]
23#
24#	TODO :	Port to all architectures (one regex per arch)
25
26use strict;
27
28# check for arch
29#
30# $re is used for two matches:
31# $& (whole re) matches the complete objdump line with the stack growth
32# $1 (first bracket) matches the size of the stack growth
33#
34# $dre is similar, but for dynamic stack redutions:
35# $& (whole re) matches the complete objdump line with the stack growth
36# $1 (first bracket) matches the dynamic amount of the stack growth
37#
38# $sub: subroutine for special handling to check stack usage.
39#
40# use anything else and feel the pain ;)
41my (@stack, $re, $dre, $sub, $x, $xs, $funcre, $min_stack);
42{
43	my $arch = shift;
44	if ($arch eq "") {
45		$arch = `uname -m`;
46		chomp($arch);
47	}
48
49	$min_stack = shift;
50	if ($min_stack eq "" || $min_stack !~ /^\d+$/) {
51		$min_stack = 100;
52	}
53
54	$x	= "[0-9a-f]";	# hex character
55	$xs	= "[0-9a-f ]";	# hex character or space
56	$funcre = qr/^$x* <(.*)>:$/;
57	if ($arch =~ '^(aarch|arm)64$') {
58		#ffffffc0006325cc:       a9bb7bfd        stp     x29, x30, [sp, #-80]!
59		#a110:       d11643ff        sub     sp, sp, #0x590
60		$re = qr/^.*stp.*sp, \#-([0-9]{1,8})\]\!/o;
61		$dre = qr/^.*sub.*sp, sp, #(0x$x{1,8})/o;
62	} elsif ($arch eq 'arm') {
63		#c0008ffc:	e24dd064	sub	sp, sp, #100	; 0x64
64		$re = qr/.*sub.*sp, sp, #([0-9]{1,4})/o;
65		$sub = \&arm_push_handling;
66	} elsif ($arch =~ /^x86(_64)?$/ || $arch =~ /^i[3456]86$/) {
67		#c0105234:       81 ec ac 05 00 00       sub    $0x5ac,%esp
68		# or
69		#    2f60:    48 81 ec e8 05 00 00       sub    $0x5e8,%rsp
70		$re = qr/^.*[as][du][db]    \$(0x$x{1,8}),\%(e|r)sp$/o;
71		$dre = qr/^.*[as][du][db]    (%.*),\%(e|r)sp$/o;
72	} elsif ($arch eq 'ia64') {
73		#e0000000044011fc:       01 0f fc 8c     adds r12=-384,r12
74		$re = qr/.*adds.*r12=-(([0-9]{2}|[3-9])[0-9]{2}),r12/o;
75	} elsif ($arch eq 'm68k') {
76		#    2b6c:       4e56 fb70       linkw %fp,#-1168
77		#  1df770:       defc ffe4       addaw #-28,%sp
78		$re = qr/.*(?:linkw %fp,|addaw )#-([0-9]{1,4})(?:,%sp)?$/o;
79	} elsif ($arch eq 'mips64') {
80		#8800402c:       67bdfff0        daddiu  sp,sp,-16
81		$re = qr/.*daddiu.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
82	} elsif ($arch eq 'mips') {
83		#88003254:       27bdffe0        addiu   sp,sp,-32
84		$re = qr/.*addiu.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
85	} elsif ($arch eq 'nios2') {
86		#25a8:	defffb04 	addi	sp,sp,-20
87		$re = qr/.*addi.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
88	} elsif ($arch eq 'openrisc') {
89		# c000043c:       9c 21 fe f0     l.addi r1,r1,-272
90		$re = qr/.*l\.addi.*r1,r1,-(([0-9]{2}|[3-9])[0-9]{2})/o;
91	} elsif ($arch eq 'parisc' || $arch eq 'parisc64') {
92		$re = qr/.*ldo ($x{1,8})\(sp\),sp/o;
93	} elsif ($arch eq 'powerpc' || $arch =~ /^ppc(64)?(le)?$/ ) {
94		# powerpc    : 94 21 ff 30     stwu    r1,-208(r1)
95		# ppc64(le)  : 81 ff 21 f8     stdu    r1,-128(r1)
96		$re = qr/.*st[dw]u.*r1,-($x{1,8})\(r1\)/o;
97	} elsif ($arch =~ /^s390x?$/) {
98		#   11160:       a7 fb ff 60             aghi   %r15,-160
99		# or
100		#  100092:	 e3 f0 ff c8 ff 71	 lay	 %r15,-56(%r15)
101		$re = qr/.*(?:lay|ag?hi).*\%r15,-(([0-9]{2}|[3-9])[0-9]{2})
102		      (?:\(\%r15\))?$/ox;
103	} elsif ($arch =~ /^sh64$/) {
104		#XXX: we only check for the immediate case presently,
105		#     though we will want to check for the movi/sub
106		#     pair for larger users. -- PFM.
107		#a00048e0:       d4fc40f0        addi.l  r15,-240,r15
108		$re = qr/.*addi\.l.*r15,-(([0-9]{2}|[3-9])[0-9]{2}),r15/o;
109	} elsif ($arch eq 'sparc' || $arch eq 'sparc64') {
110		# f0019d10:       9d e3 bf 90     save  %sp, -112, %sp
111		$re = qr/.*save.*%sp, -(([0-9]{2}|[3-9])[0-9]{2}), %sp/o;
112	} elsif ($arch =~ /^riscv(64)?$/) {
113		#ffffffff8036e868:	c2010113          	addi	sp,sp,-992
114		$re = qr/.*addi.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o;
115	} else {
116		print("wrong or unknown architecture \"$arch\"\n");
117		exit
118	}
119}
120
121#
122# To count stack usage of push {*, fp, ip, lr, pc} instruction in ARM,
123# if FRAME POINTER is enabled.
124# e.g. c01f0d48: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc}
125#
126sub arm_push_handling {
127	my $regex = qr/.*push.*fp, ip, lr, pc}/o;
128	my $size = 0;
129	my $line_arg = shift;
130
131	if ($line_arg =~ m/$regex/) {
132		$size = $line_arg =~ tr/,//;
133		$size = ($size + 1) * 4;
134	}
135
136	return $size;
137}
138
139#
140# main()
141#
142my ($func, $file, $lastslash, $total_size, $addr, $intro);
143
144$total_size = 0;
145
146while (my $line = <STDIN>) {
147	if ($line =~ m/$funcre/) {
148		$func = $1;
149		next if $line !~ m/^($xs*)/;
150		if ($total_size > $min_stack) {
151			push @stack, "$intro$total_size\n";
152		}
153
154		$addr = $1;
155		$addr =~ s/ /0/g;
156		$addr = "0x$addr";
157
158		$intro = "$addr $func [$file]:";
159		my $padlen = 56 - length($intro);
160		while ($padlen > 0) {
161			$intro .= '	';
162			$padlen -= 8;
163		}
164
165		$total_size = 0;
166	}
167	elsif ($line =~ m/(.*):\s*file format/) {
168		$file = $1;
169		$file =~ s/\.ko//;
170		$lastslash = rindex($file, "/");
171		if ($lastslash != -1) {
172			$file = substr($file, $lastslash + 1);
173		}
174	}
175	elsif ($line =~ m/$re/) {
176		my $size = $1;
177		$size = hex($size) if ($size =~ /^0x/);
178
179		if ($size > 0xf0000000) {
180			$size = - $size;
181			$size += 0x80000000;
182			$size += 0x80000000;
183		}
184		next if ($size > 0x10000000);
185
186		$total_size += $size;
187	}
188	elsif (defined $dre && $line =~ m/$dre/) {
189		my $size = $1;
190
191		$size = hex($size) if ($size =~ /^0x/);
192		$total_size += $size;
193	}
194	elsif (defined $sub) {
195		my $size = &$sub($line);
196
197		$total_size += $size;
198	}
199}
200if ($total_size > $min_stack) {
201	push @stack, "$intro$total_size\n";
202}
203
204# Sort output by size (last field)
205print sort { ($b =~ /:\t*(\d+)$/)[0] <=> ($a =~ /:\t*(\d+)$/)[0] } @stack;
206