diff --git a/libunwind/src/UnwindRustSgx.h b/libunwind/src/UnwindRustSgx.h
index 087b078cd0b78a..fad3c358408e72 100644
--- a/libunwind/src/UnwindRustSgx.h
+++ b/libunwind/src/UnwindRustSgx.h
@@ -21,29 +21,15 @@
 #include <stdint.h>
 
 // We have to use RWLock from rust repo, it is defined in:
-// src/libstd/sys/sgx/rwlock.rs.
-// rwlock.rs has compile time check to ensure sizeof(RWLock) = 128.
+// src/libstd/sys/sgx/unwind.rs.
+// unwind.rs has compile time check to ensure sizeof(RWLock) = 16.
 typedef struct {
-    unsigned char opaque[128];
-} RWLock;
+    unsigned char opaque[16];
+} __attribute__ ((aligned (8))) RWLock;
 
 // The below is obtained by printing initialized bytes
-// for RWLock in rust repo: src/libstd/sys/sgx/rwlock.rs.
+// for RWLock in rust repo: src/libstd/sys/sgx/unwind.rs.
 #define RWLOCK_INIT { \
-    0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x3, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x3, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
-    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
     0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
     0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, \
 }
diff --git a/libunwind/src/UnwindRustSgxSnprintf.c b/libunwind/src/UnwindRustSgxSnprintf.c
index a3246b02e2c29f..8394f213f66cf0 100644
--- a/libunwind/src/UnwindRustSgxSnprintf.c
+++ b/libunwind/src/UnwindRustSgxSnprintf.c
@@ -10,7 +10,9 @@
 #pragma GCC diagnostic ignored "-Wfloat-conversion"
 #pragma GCC diagnostic ignored "-Wsign-conversion"
 #pragma GCC diagnostic ignored "-Wstrict-overflow"
+#if __GNUC__ >= 7
 #pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+#endif
 
 /**************************************************************
  * Original: