From ee417882e07277b2a36e7e61e6ef7edd96415b3f Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 4 Oct 2017 17:18:23 -0700
Subject: [PATCH] Don't use hidden visibility in libc.a with PIE on i386

On i386, when multi-arch is enabled, all external functions must be
called via PIC PLT in PIE, which requires setting up EBX register,
since they may be IFUNC functions.

	* config.h.in (NO_HIDDEN_EXTERN_FUNC_IN_PIE): New.
	* include/libc-symbols.h (__hidden_proto_hiddenattr): Add check
	for PIC and NO_HIDDEN_EXTERN_FUNC_IN_PIE.
	* sysdeps/i386/configure.ac (NO_HIDDEN_EXTERN_FUNC_IN_PIE): New
	AC_DEFINE if multi-arch is enabled.
	* sysdeps/i386/configure: Regenerated.
---
 ChangeLog                 | 9 +++++++++
 config.h.in               | 4 ++++
 include/libc-symbols.h    | 1 +
 sysdeps/i386/configure    | 7 ++++++-
 sysdeps/i386/configure.ac | 6 ++++++
 5 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 191dd5aab3..bb09add53d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2017-10-04  H.J. Lu  <hongjiu.lu@intel.com>
 
+	* config.h.in (NO_HIDDEN_EXTERN_FUNC_IN_PIE): New.
+	* include/libc-symbols.h (__hidden_proto_hiddenattr): Add check
+	for PIC and NO_HIDDEN_EXTERN_FUNC_IN_PIE.
+	* sysdeps/i386/configure.ac (NO_HIDDEN_EXTERN_FUNC_IN_PIE): New
+	AC_DEFINE if multi-arch is enabled.
+	* sysdeps/i386/configure: Regenerated.
+
+2017-10-04  H.J. Lu  <hongjiu.lu@intel.com>
+
 	* Makeconfig (+link-static-before-libc): Use
 	$(DEFAULT-LDFLAGS-$(@F)).
 	* elf/Makefile (CRT-tst-tls1-static-non-pie): New.
diff --git a/config.h.in b/config.h.in
index 0d38476fa4..c140ff3ecb 100644
--- a/config.h.in
+++ b/config.h.in
@@ -86,6 +86,10 @@
 #undef	PI_STATIC_AND_HIDDEN
 
 /* Define this to disable the 'hidden_proto' et al macros in
+   include/libc-symbols.h that avoid PLT slots in PIE.  */
+#undef  NO_HIDDEN_EXTERN_FUNC_IN_PIE
+
+/* Define this to disable the 'hidden_proto' et al macros in
    include/libc-symbols.h that avoid PLT slots in the shared objects.  */
 #undef	NO_HIDDEN
 
diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index e0d4dc3170..872626274b 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -507,6 +507,7 @@ for linking")
 #else
 # ifndef __ASSEMBLER__
 #  if !defined SHARED && IS_IN (libc) && !defined LIBC_NONSHARED \
+      && (!defined PIC || !defined NO_HIDDEN_EXTERN_FUNC_IN_PIE) \
       && !defined NO_HIDDEN
 #   define __hidden_proto_hiddenattr(attrs...) \
   __attribute__ ((visibility ("hidden"), ##attrs))
diff --git a/sysdeps/i386/configure b/sysdeps/i386/configure
index 4d6685f7c2..4cf968d8bc 100644
--- a/sysdeps/i386/configure
+++ b/sysdeps/i386/configure
@@ -26,7 +26,7 @@ libc_compiler_builtin_inlined=no
 cat > conftest.c <<EOF
 int _start (void) { int a, b, c; __sync_val_compare_and_swap (&a, b, c); return 0; }
 EOF
-if ! { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS
+if ! { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
 		     -O0 -nostdlib -nostartfiles
 		     -S conftest.c -o - | fgrep "__sync_val_compare_and_swap"
 		     1>&5'
@@ -79,3 +79,8 @@ fi
 
 $as_echo "#define PI_STATIC_AND_HIDDEN 1" >>confdefs.h
 
+
+if test x"$multi_arch" != xno; then
+  $as_echo "#define NO_HIDDEN_EXTERN_FUNC_IN_PIE 1" >>confdefs.h
+
+fi
diff --git a/sysdeps/i386/configure.ac b/sysdeps/i386/configure.ac
index f7766ad2b8..b598b120bc 100644
--- a/sysdeps/i386/configure.ac
+++ b/sysdeps/i386/configure.ac
@@ -48,3 +48,9 @@ fi
 dnl It is always possible to access static and hidden symbols in an
 dnl position independent way.
 AC_DEFINE(PI_STATIC_AND_HIDDEN)
+
+dnl When multi-arch is enabled, all external functions must be called
+dnl via PIC PLT in PIE, which requires setting up EBX register.
+if test x"$multi_arch" != xno; then
+  AC_DEFINE(NO_HIDDEN_EXTERN_FUNC_IN_PIE)
+fi
-- 
2.11.4.GIT