From 2086edb799acf6ad5ef0bb53aa3b17abf4f7f992 Mon Sep 17 00:00:00 2001 From: David Benjamin Date: Tue, 29 Jan 2019 05:12:15 +0000 Subject: Fix some CFI issues in x86_64 assembly The add/double shortcut in ecp_nistz256-x86_64.pl left one instruction point that did not unwind, and the "slow" path in AES_cbc_encrypt was not annotated correctly. For the latter, add .cfi_{remember,restore}_state support to perlasm. Next, fill in a bunch of functions that are missing no-op .cfi_startproc and .cfi_endproc blocks. libunwind cannot unwind those stack frames otherwise. Finally, work around a bug in libunwind by not encoding rflags. (rflags isn't a callee-saved register, so there's not much need to annotate it anyway.) These were found as part of ABI testing work in BoringSSL. Reviewed-by: Richard Levitte GH: #8109 (cherry picked from commit c0e8e5007ba5234d4d448e82a1567e0c4467e629) --- crypto/perlasm/x86_64-xlate.pl | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'crypto/perlasm') diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl index f8380f2e9c..b81d03a753 100755 --- a/crypto/perlasm/x86_64-xlate.pl +++ b/crypto/perlasm/x86_64-xlate.pl @@ -541,6 +541,7 @@ my %globals; ); my ($cfa_reg, $cfa_rsp); + my @cfa_stack; # [us]leb128 format is variable-length integer representation base # 2^128, with most significant bit of each byte being 0 denoting @@ -688,6 +689,14 @@ my %globals; cfa_expression($$line))); last; }; + /remember_state/ + && do { push @cfa_stack, [$cfa_reg, $cfa_rsp]; + last; + }; + /restore_state/ + && do { ($cfa_reg, $cfa_rsp) = @{pop @cfa_stack}; + last; + }; } $self->{value} = ".cfi_$dir\t$$line" if ($dir); -- cgit v1.2.3