[Feature][ZXW-33]merge ZXW 0428 version

Change-Id: I11f167edfea428d9fab198ff00ff1364932d1b0b
diff --git a/ap/libc/glibc/glibc-2.23/nptl/pt-vfork.c b/ap/libc/glibc/glibc-2.23/nptl/pt-vfork.c
new file mode 100644
index 0000000..8f4be0c
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/nptl/pt-vfork.c
@@ -0,0 +1,77 @@
+/* vfork ABI-compatibility entry points for libpthread.
+   Copyright (C) 2014-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+#include <shlib-compat.h>
+
+/* libpthread used to have its own vfork implementation that differed
+   from libc's only in having a pointless micro-optimization.  There
+   is no longer any use to having a separate copy in libpthread, but
+   the historical ABI requires it.  For static linking, there is no
+   need to provide anything here--the libc version will be linked in.
+   For shared library ABI compatibility, there must be __vfork and
+   vfork symbols in libpthread.so; so we define them using IFUNC to
+   redirect to the libc function.  */
+
+/* Note! If the architecture doesn't support IFUNC, then we need an
+   alternate target-specific mechanism to implement this.  So we just
+   assume IFUNC here and require that the target override this file
+   if necessary.
+
+   If the architecture can assume all supported versions of gcc will
+   produce a tail-call to __libc_vfork, consider including the version
+   in sysdeps/unix/sysv/linux/aarch64/pt-vfork.c.  */
+
+#if !HAVE_IFUNC
+# error "must write pt-vfork for this machine or get IFUNC support"
+#endif
+
+#if (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \
+     || SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20))
+
+extern __typeof (vfork) __libc_vfork;   /* Defined in libc.  */
+
+static __typeof (vfork) *
+__attribute__ ((used))
+vfork_resolve (void)
+{
+  return &__libc_vfork;
+}
+
+# ifdef HAVE_ASM_SET_DIRECTIVE
+#  define DEFINE_VFORK(name) \
+  asm (".set " #name ", vfork_resolve\n" \
+       ".globl " #name "\n" \
+       ".type " #name ", %gnu_indirect_function");
+# else
+#  define DEFINE_VFORK(name) \
+  asm (#name " = vfork_resolve\n" \
+       ".globl " #name "\n" \
+       ".type " #name ", %gnu_indirect_function");
+# endif
+#endif
+
+#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20)
+DEFINE_VFORK (vfork_ifunc)
+compat_symbol (libpthread, vfork_ifunc, vfork, GLIBC_2_0);
+#endif
+
+#if SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)
+DEFINE_VFORK (__vfork_ifunc)
+compat_symbol (libpthread, __vfork_ifunc, __vfork, GLIBC_2_1_2);
+#endif