--- lxc-2.0.8/src/lxc/rexec.c.orig	2019-02-13 09:54:35.316707658 +0100
+++ lxc-2.0.8/src/lxc/rexec.c	2019-02-13 13:20:49.551747667 +0100
@@ -37,6 +37,17 @@
 #define LXC_MEMFD_REXEC_SEALS \
 	(F_SEAL_SEAL | F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE)
 
+/* Re-alllocate a pointer, do not fail */
+static void *must_realloc(void *orig, size_t sz)
+{
+	void *ret;
+
+	do {
+		ret = realloc(orig, sz);
+	} while (!ret);
+	return ret;
+}
+
 static int push_vargs(char *data, int data_length, char ***output)
 {
 	int num = 0;
@@ -164,6 +175,50 @@
 	return ret;
 }
 
+#ifndef HAVE_MEMFD_CREATE
+static int memfd_create(const char *name, unsigned int flags) {
+	#ifndef __NR_memfd_create
+		#if defined __i386__
+			#define __NR_memfd_create 356
+		#elif defined __x86_64__
+			#define __NR_memfd_create 319
+		#elif defined __arm__
+			#define __NR_memfd_create 385
+		#elif defined __aarch64__
+			#define __NR_memfd_create 279
+		#elif defined __s390__
+			#define __NR_memfd_create 350
+		#elif defined __powerpc__
+			#define __NR_memfd_create 360
+		#elif defined __sparc__
+			#define __NR_memfd_create 348
+		#elif defined __blackfin__
+			#define __NR_memfd_create 390
+		#elif defined __ia64__
+			#define __NR_memfd_create 1340
+		#elif defined _MIPS_SIM
+			#if _MIPS_SIM == _MIPS_SIM_ABI32
+				#define __NR_memfd_create 4354
+			#endif
+			#if _MIPS_SIM == _MIPS_SIM_NABI32
+				#define __NR_memfd_create 6318
+			#endif
+			#if _MIPS_SIM == _MIPS_SIM_ABI64
+				#define __NR_memfd_create 5314
+			#endif
+		#endif
+	#endif
+	#ifdef __NR_memfd_create
+	return syscall(__NR_memfd_create, name, flags);
+	#else
+	errno = ENOSYS;
+	return -1;
+	#endif
+}
+#else
+extern int memfd_create(const char *name, unsigned int flags);
+#endif
+
 static void lxc_rexec_as_memfd(char **argv, char **envp, const char *memfd_name)
 {
 	int saved_errno;