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 b81d03a7533045114a87f0618bf2b8554ab46dc6..1b0bf42f8ce1ca5d8df99dc0f3b0006d1a3492f1 100755 (executable)
--- 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/