From eddafda6460c8591678cc354519afe69b7e3f472 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Sat, 27 Jan 2018 13:14:03 -0800
Subject: [PATCH] build-sys: Check if memfd_create is already defined

glibc 2.27+ has introduced this function

BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=104815
---
 configure.ac                   | 7 +++++++
 src/pulsecore/memfd-wrappers.h | 4 ++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 77b5ff5..aa97944 100644
--- a/configure.ac
+++ b/configure.ac
@@ -603,6 +603,10 @@ AS_IF([test "x$enable_memfd" != "xno"],
     AC_CHECK_DECL(SYS_memfd_create, [HAVE_MEMFD=1], [HAVE_MEMFD=0], [#include <sys/syscall.h>]),
     [HAVE_MEMFD=0])
 
+AS_IF([test "x$enable_memfd" != "xno"],
+    AC_CHECK_FUNC(memfd_create, [HAVE_MEMFD_CREATE=1], [HAVE_MEMFD_CREATE=0], [#include <sys/mman.h>]),
+    [HAVE_MEMFD_CREATE=0])
+
 AS_IF([test "x$enable_memfd" = "xyes" && test "x$HAVE_MEMFD" = "x0"],
     [AC_MSG_ERROR([*** Your Linux kernel does not support memfd shared memory.
                   *** Use linux v3.17 or higher for such a feature.])])
@@ -610,6 +614,9 @@ AS_IF([test "x$enable_memfd" = "xyes" && test "x$HAVE_MEMFD" = "x0"],
 AC_SUBST(HAVE_MEMFD)
 AM_CONDITIONAL([HAVE_MEMFD], [test "x$HAVE_MEMFD" = x1])
 AS_IF([test "x$HAVE_MEMFD" = "x1"], AC_DEFINE([HAVE_MEMFD], 1, [Have memfd shared memory.]))
+AC_SUBST(HAVE_MEMFD_CREATE)
+AM_CONDITIONAL([HAVE_MEMFD_CREATE], [test "x$HAVE_MEMFD_CREATE" = x1])
+AS_IF([test "x$HAVE_MEMFD_CREATE" = "x1"], AC_DEFINE([HAVE_MEMFD_CREATE], 1, [Define to 1 if you have the `memfd_create` function.]))
 
 #### X11 (optional) ####
 
diff --git a/src/pulsecore/memfd-wrappers.h b/src/pulsecore/memfd-wrappers.h
index 3bed9b2..87ed758 100644
--- a/src/pulsecore/memfd-wrappers.h
+++ b/src/pulsecore/memfd-wrappers.h
@@ -32,11 +32,11 @@
  * defined in the kernel header file <linux/fcntl.h>, that file as
  * a whole conflicts with the original glibc header <fnctl.h>.
  */
-
+#ifndef HAVE_MEMFD_CREATE
 static inline int memfd_create(const char *name, unsigned int flags) {
     return syscall(SYS_memfd_create, name, flags);
 }
-
+#endif
 /* memfd_create(2) flags */
 
 #ifndef MFD_CLOEXEC
-- 
2.16.1