From: David Benjamin <davidben@google.com>
Date: Tue, 29 Jan 2019 23:41:39 +0000 (-0600)
Subject: Check for unpaired .cfi_remember_state
X-Git-Tag: OpenSSL_1_1_1b~27
X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff_plain;h=2e826078410bdb117710890b0e99bbdbbbf7e95d

Check for unpaired .cfi_remember_state

Reviewed-by: Richard Levitte <levitte@openssl.org>
GH: #8109
(cherry picked from commit e09633107b7e987b2179850715ba60d8fb069278)
---

diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl
index b81d03a753..1b0bf42f8c 100755
--- a/crypto/perlasm/x86_64-xlate.pl
+++ b/crypto/perlasm/x86_64-xlate.pl
@@ -649,7 +649,13 @@ my %globals;
 	    # why it starts with -8. Recall that CFA is top of caller's
 	    # stack...
 	    /startproc/	&& do {	($cfa_reg, $cfa_rsp) = ("%rsp", -8); last; };
-	    /endproc/	&& do {	($cfa_reg, $cfa_rsp) = ("%rsp",  0); last; };
+	    /endproc/	&& do {	($cfa_reg, $cfa_rsp) = ("%rsp",  0);
+				# .cfi_remember_state directives that are not
+				# matched with .cfi_restore_state are
+				# unnecessary.
+				die "unpaired .cfi_remember_state" if (@cfa_stack);
+				last;
+			      };
 	    /def_cfa_register/
 			&& do {	$cfa_reg = $$line; last; };
 	    /def_cfa_offset/