find dynamic stack allocations in checkstack.pl
PATCH 1/1 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)
---
scripts/checkstack.pl +23 -1
@@ -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 "") {
@@ -47,9 +51,11 @@ my (@stack, $re, $x, $xs); } elsif ($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;
@@ -142,6 +148,22 @@ while (my $line = <STDIN>) { next if ($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;
scripts/checkstack.pl while (my $line = <STDIN>) { · line 151
Quoted 6 lines · Eric Sandeen
scripts/checkstack.pl +1
-0@@ -142,6 +148,22 @@ while (my $line = <STDIN>) { next if ($size < 100); push @stack, "$intro$size\n"; } + elsif (defined $dre && $line =~ m/$dre/) {
These two could join a line. Otherwise an excellent addition.
Jörn
Signature · 2 lines
"Translations are and will always be problematic. They inflict violence upon two languages." (translation from German)
Quoted 8 lines · Jörn Engel
scripts/checkstack.pl while (my $line = <STDIN>) { · line 151
Quoted 5 lines · Eric Sandeen
scripts/checkstack.pl +1
-0@@ -142,6 +148,22 @@ while (my $line = <STDIN>) { next if ($size < 100); push @stack, "$intro$size\n"; } + elsif (defined $dre && $line =~ m/$dre/) {These two could join a line. Otherwise an excellent addition.
Thanks... was just following the existing style (in this part of the file, anyway...)
-Eric
Quoted 4 lines
Reviewed-by Joern Engel <[email protected]>Jörn