find dynamic stack allocations in checkstack.pl
Currently, checkstack.pl only looks for fixed subtractions from the stack
pointer. However, things like this:
void function(int size)
{
char stackbuster[size << 2];
...
are certainly worth pointing out, I think.
This could perhaps be done more cleanly, and the following patch only
adds "dynamic" REs for x86 and x86_64, but it works:
0x00b0 crypto_cbc_decrypt_inplace [cbc]: Dynamic (%rax)
0x00ad crypto_pcbc_decrypt_inplace [pcbc]: Dynamic (%rax)
0x02f6 crypto_pcbc_encrypt_inplace [pcbc]: Dynamic (%rax)
0x036c _crypto_xcbc_digest_setkey [xcbc]: Dynamic (%rax)
...
(Inspired by Keith Owens' old stack-check script)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/checkstack.pl b/scripts/checkstack.pl
index 340ad69..358f96c 100755
--- a/scripts/checkstack.pl
+++ b/scripts/checkstack.pl
@@ -26,8 +26,12 @@
# $& (whole re) matches the complete objdump line with the stack growth
# $1 (first bracket) matches the size of the stack growth
#
+# $dre is similar, but for dynamic stack redutions:
+# $& (whole re) matches the complete objdump line with the stack growth
+# $1 (first bracket) matches the dynamic amount of the stack growth
+#
# use anything else and feel the pain ;)
-my (@stack, $re, $x, $xs);
+my (@stack, $re, $dre, $x, $xs);
{
my $arch = shift;
if ($arch eq "") {
@@ -46,9 +50,11 @@
} elsif ($arch =~ /^i[3456]86$/) {
#c0105234: 81 ec ac 05 00 00 sub $0x5ac,%esp
$re = qr/^.*[as][du][db] \$(0x$x{1,8}),\%esp$/o;
+ $dre = qr/^.*[as][du][db] (%.*),\%esp$/o;
} elsif ($arch eq 'x86_64') {
# 2f60: 48 81 ec e8 05 00 00 sub $0x5e8,%rsp
$re = qr/^.*[as][du][db] \$(0x$x{1,8}),\%rsp$/o;
+ $dre = qr/^.*[as][du][db] (\%.*),\%rsp$/o;
} elsif ($arch eq 'ia64') {
#e0000000044011fc: 01 0f fc 8c adds r12=-384,r12
$re = qr/.*adds.*r12=-(([0-9]{2}|[3-9])[0-9]{2}),r12/o;
@@ -141,6 +147,22 @@
next if ($size < 100);
push @stack, "$intro$size\n";
}
+ elsif (defined $dre && $line =~ m/$dre/) {
+ my $size = "Dynamic ($1)";
+
+ next if $line !~ m/^($xs*)/;
+ my $addr = $1;
+ $addr =~ s/ /0/g;
+ $addr = "0x$addr";
+
+ my $intro = "$addr $func [$file]:";
+ my $padlen = 56 - length($intro);
+ while ($padlen > 0) {
+ $intro .= ' ';
+ $padlen -= 8;
+ }
+ push @stack, "$intro$size\n";
+ }
}
print sort bysize @stack;