From b2b43d1b698235ee674e588c224db38d9b78d1ea Mon Sep 17 00:00:00 2001 From: Richard Levitte Date: Fri, 17 Jan 2020 08:29:28 +0100 Subject: [PATCH] Add GNU properties note for Intel CET in x86_64-xlate.pl This appears to be emitted with gcc and clang with -fcf-protection selected, so we should do the same. We're trying to be smart, and only emit this when the 'endbranch' pseudo-mnemonic has been used at least once. This is inspired by and owes to work done by @hjl-tools (github) Reviewed-by: Bernd Edlinger (Merged from https://github.com/openssl/openssl/pull/10875) --- crypto/perlasm/x86_64-xlate.pl | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl index 4a7ec7a6e9..e5644014ab 100755 --- a/crypto/perlasm/x86_64-xlate.pl +++ b/crypto/perlasm/x86_64-xlate.pl @@ -101,6 +101,24 @@ elsif (!$gas) $decor="\$L\$"; } +my $cet_property = <<'_____'; + .section ".note.gnu.property", "a" + .align 8 + .long 1f - 0f + .long 4f - 1f + .long 5 +0: + .asciz "GNU" +1: + .align 8 + .long 0xc0000002 + .long 3f - 2f +2: + .long 3 +3: + .p2align 3 +4: +_____ my $current_segment; my $current_function; my %globals; @@ -1127,7 +1145,9 @@ my $vprotq = sub { # Intel Control-flow Enforcement Technology extension. All functions and # indirect branch targets will have to start with this instruction... +my $used_cet = 0; my $endbranch = sub { + $used_cet = 1; (0xf3,0x0f,0x1e,0xfa); }; @@ -1213,6 +1233,7 @@ while(defined(my $line=<>)) { print $line,"\n"; } +print "$cet_property" if ($gas && $used_cet); print "\n$current_segment\tENDS\n" if ($current_segment && $masm); print "END\n" if ($masm); -- 2.25.1