From 7acebaa837c8990057cac6150d53b9912ab8f5fe Mon Sep 17 00:00:00 2001
From: Daniel Micay <danielmicay@gmail.com>
Date: Tue, 26 Mar 2019 01:45:15 -0400
Subject: [PATCH] overhaul glibc compatibility workarounds

---
 util.h | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/util.h b/util.h
index 82af552..3e76fd7 100644
--- a/util.h
+++ b/util.h
@@ -39,20 +39,30 @@ typedef uint64_t u64;
 typedef unsigned __int128 u128;
 
 // use __register_atfork directly to avoid linking with libpthread for glibc < 2.28
-#if defined(__GLIBC__) && !__GLIBC_PREREQ(2, 28)
+#ifdef __GLIBC__
+#if !__GLIBC_PREREQ(2, 28)
 extern void *__dso_handle;
 extern int __register_atfork(void (*)(void), void (*)(void), void (*)(void), void *);
 #define atfork(prepare, parent, child) __register_atfork(prepare, parent, child, __dso_handle)
-#else
+#endif
+#endif
+
+#ifndef atfork
 #define atfork pthread_atfork
 #endif
 
 #ifdef CONFIG_SEAL_METADATA
-#if defined(__GLIBC__) && __GLIBC_PREREQ(2, 27)
+
+#ifdef __GLIBC__
+#if __GLIBC_PREREQ(2, 27)
 #define USE_PKEY
-#else
-#error "CONFIG_SEAL_METADATA requires Memory Protection Key support"
 #endif
 #endif
 
+#ifndef USE_PKEY
+#error "CONFIG_SEAL_METADATA requires Memory Protection Key support"
+#endif
+
+#endif // CONFIG_SEAL_METADATA
+
 #endif