[binutils-gdb] GCC_CET_HOST_FLAGS: Check if host supports multi-byte NOPs

[H.J. Lu]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=538c15fc2a29ff142f2ec71d253d4027946ece09

commit 538c15fc2a29ff142f2ec71d253d4027946ece09
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Thu Mar 18 07:54:15 2021 -0700

    GCC_CET_HOST_FLAGS: Check if host supports multi-byte NOPs
    
    Check if host supports multi-byte NOPs before enabling CET on host.
    
    config/
    
            PR binutils/27397
            * cet.m4 (GCC_CET_HOST_FLAGS): Check if host supports multi-byte
            NOPs.
    
    libiberty/
    
            PR binutils/27397
            * configure: Regenerated.

Diff:
---
 config/ChangeLog    |  6 ++++++
 config/cet.m4       | 19 ++++++++++++++++---
 libiberty/ChangeLog |  5 +++++
 libiberty/configure | 29 +++++++++++++++++++++++++++++
 4 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/config/ChangeLog b/config/ChangeLog
index 95dcc85b42b..6f7b3c73a1a 100644
--- a/config/ChangeLog
+++ b/config/ChangeLog
@@ -1,3 +1,9 @@
+2021-03-18  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR binutils/27397
+	* cet.m4 (GCC_CET_HOST_FLAGS): Check if host supports multi-byte
+	NOPs.
+
 2021-02-13  Mike Frysinger  <vapier@gentoo.org>
 
 	* debuginfod.m4: Delete m4_include(../config/pkg.m4).
diff --git a/config/cet.m4 b/config/cet.m4
index c67fb4f35b6..7718be1afe8 100644
--- a/config/cet.m4
+++ b/config/cet.m4
@@ -130,6 +130,18 @@ fi
 if test x$may_have_cet = xyes; then
   if test x$cross_compiling = xno; then
     AC_TRY_RUN([
+int
+main ()
+{
+  asm ("endbr32");
+  return 0;
+}
+    ],
+    [have_multi_byte_nop=yes],
+    [have_multi_byte_nop=no])
+    have_cet=no
+    if test x$have_multi_byte_nop = xyes; then
+      AC_TRY_RUN([
 static void
 foo (void)
 {
@@ -155,9 +167,10 @@ main ()
   bar ();
   return 0;
 }
-    ],
-    [have_cet=no],
-    [have_cet=yes])
+      ],
+      [have_cet=no],
+      [have_cet=yes])
+    fi
     if test x$enable_cet = xno -a x$have_cet = xyes; then
       AC_MSG_ERROR([Intel CET must be enabled on Intel CET enabled host])
     fi
diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index 8e5f5dc4bfa..70d7209bf0a 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,8 @@
+2021-03-18  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR binutils/27397
+	* configure: Regenerated.
+
 2021-01-11  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/27173
diff --git a/libiberty/configure b/libiberty/configure
index 160b8c9e8b1..29a690d44fc 100755
--- a/libiberty/configure
+++ b/libiberty/configure
@@ -5539,6 +5539,34 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
+int
+main ()
+{
+  asm ("endbr32");
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  have_multi_byte_nop=yes
+else
+  have_multi_byte_nop=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+    have_cet=no
+    if test x$have_multi_byte_nop = xyes; then
+      if test "$cross_compiling" = yes; then :
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot run test program while cross compiling
+See \`config.log' for more details" "$LINENO" 5; }
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
 static void
 foo (void)
 {
@@ -5575,6 +5603,7 @@ rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
   conftest.$ac_objext conftest.beam conftest.$ac_ext
 fi
 
+    fi
     if test x$enable_cet = xno -a x$have_cet = xyes; then
       as_fn_error $? "Intel CET must be enabled on Intel CET enabled host" "$LINENO" 5
     fi