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 
25 use 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 ;)
40 my (@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 #
118 sub 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 $size;
129 }
130 
131 #
132 # main()
133 #
134 my ($func, $file, $lastslash, $total_size, $addr, $intro);
135 
136 $total_size = 0;
137 
138 while (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 += $size;
186 	}
187 }
188 if ($total_size > $min_stack) {
189 	push @stack, "$intro$total_size\n";
190 }
191 
192 # Sort output by size (last field) and function name if size is the same
193 sub sort_lines {
194 	my ($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 $func_b;
205 	}
206 }
207 
208 print sort { sort_lines($a, $b) } @stack;
209