From 2fa58080cbcdb42bda0438e2d37bdd8a4436a6f4 Mon Sep 17 00:00:00 2001
From: joboet <jonasboettiger@icloud.com>
Date: Mon, 5 Sep 2022 11:42:46 +0200
Subject: [PATCH] std: check if TCS is a null pointer

---
 library/std/src/sys/sgx/abi/thread.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/library/std/src/sys/sgx/abi/thread.rs b/library/std/src/sys/sgx/abi/thread.rs
index ef55b821a2b..2b23e368cc3 100644
--- a/library/std/src/sys/sgx/abi/thread.rs
+++ b/library/std/src/sys/sgx/abi/thread.rs
@@ -7,7 +7,11 @@ use fortanix_sgx_abi::Tcs;
 #[unstable(feature = "sgx_platform", issue = "56975")]
 pub fn current() -> Tcs {
     extern "C" {
-        fn get_tcs_addr() -> Tcs;
+        fn get_tcs_addr() -> *mut u8;
+    }
+    let addr = unsafe { get_tcs_addr() };
+    match Tcs::new(addr) {
+        Some(tcs) => tcs,
+        None => rtabort!("TCS must not be placed at address zero (this is a linker error)"),
     }
-    unsafe { get_tcs_addr() }
 }