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.

diff --git a/ChangeLog b/ChangeLog
index 191dd5aab3d8a30296ded6f5d77b2d9d16e315ab..bb09add53d9f58b211172e45f5074f77cb2f6f87 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+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

diff --git a/config.h.in b/config.h.in
index 0d38476fa43c7b7db6be555951430533c9af7afb..c140ff3ecb22dea0e4c7d845ca63521738a99b2a 100644 (file)
--- a/config.h.in
+++ b/config.h.in
@@ -85,6 +85,10 @@
    and does not need relocations.  */
 #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 e0d4dc3170ae4ae78da97b28e5323224cc83b5e5..872626274bd96aa626e0919eda69b669275e02fb 100644 (file)
--- 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 4d6685f7c2001c4dc85cbfe4e5b52455ac88f0ff..4cf968d8bc2d1f85fd6a2c1faba24bbaee75e287 100644 (file)
--- 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 f7766ad2b8a33f4ecd4c450a12b421cba7cd1fc7..b598b120bcd734b11e651e17f8718e05046238d9 100644 (file)
--- 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