Messages in this thread Patch in this message | | | Date | Fri, 02 May 2008 12:26:29 -0500 | From | Eric Sandeen <> | Subject | [PATCH] find dynamic stack allocations in checkstack.pl |
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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> ---
Index: linux-2.6.25/scripts/checkstack.pl =================================================================== --- linux-2.6.25.orig/scripts/checkstack.pl 2008-05-02 12:18:15.426407528 -0500 +++ linux-2.6.25/scripts/checkstack.pl 2008-05-02 12:18:25.989469552 -0500 @@ -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;
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