From 373989eaae98351bf2c41a04e85c2128ba9d6e1a Mon Sep 17 00:00:00 2001
From: Jethro Beekman <jethro@fortanix.com>
Date: Sun, 18 Nov 2018 17:04:00 +0530
Subject: [PATCH] Add SGX target

---
 src/lib.rs |  5 ++++
 src/sgx.rs | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 src/sgx.rs

diff --git a/src/lib.rs b/src/lib.rs
index 9e1a878..acfd228 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,6 +13,7 @@
 
 #![cfg_attr(feature = "allocator-api", feature(allocator_api))]
 #![cfg_attr(target_arch = "wasm32", feature(link_llvm_intrinsics))]
+#![cfg_attr(target_env = "sgx", feature(asm))]
 #![cfg_attr(not(feature = "allocator-api"), allow(dead_code))]
 #![no_std]
 #![deny(missing_docs)]
@@ -51,6 +52,10 @@ mod sys;
 #[path = "linux.rs"]
 mod sys;
 
+#[cfg(target_env = "sgx")]
+#[path = "sgx.rs"]
+mod sys;
+
 impl Dlmalloc {
     /// Creates a new instance of an allocator, same as `DLMALLOC_INIT`.
     pub fn new() -> Dlmalloc {
diff --git a/src/sgx.rs b/src/sgx.rs
new file mode 100644
index 0000000..ee63671
--- /dev/null
+++ b/src/sgx.rs
@@ -0,0 +1,68 @@
+use core::ptr;
+use core::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
+
+// Do not remove inline: will result in relocation failure
+#[inline(always)]
+unsafe fn rel_ptr_mut<T>(offset: u64) -> *mut T {
+    (image_base()+offset) as *mut T
+}
+
+// Do not remove inline: will result in relocation failure
+// For the same reason we use inline ASM here instead of an extern static to
+// locate the base
+#[inline(always)]
+fn image_base() -> u64 {
+    let base;
+    unsafe{asm!("lea IMAGE_BASE(%rip),$0":"=r"(base))};
+    base
+}
+
+pub unsafe fn alloc(_size: usize) -> (*mut u8, usize, u32) {
+    extern {
+        static HEAP_BASE: u64;
+        static HEAP_SIZE: usize;
+    }
+    static INIT: AtomicBool = ATOMIC_BOOL_INIT;
+    // No ordering requirement since this function is protected by the global lock.
+    if !INIT.swap(true, Ordering::Relaxed) {
+        (rel_ptr_mut(HEAP_BASE), HEAP_SIZE, 0)
+    } else {
+        (ptr::null_mut(), 0, 0)
+    }
+}
+
+pub unsafe fn remap(_ptr: *mut u8, _oldsize: usize, _newsize: usize, _can_move: bool)
+    -> *mut u8
+{
+    ptr::null_mut()
+}
+
+pub unsafe fn free_part(_ptr: *mut u8, _oldsize: usize, _newsize: usize) -> bool {
+    false
+}
+
+pub unsafe fn free(_ptr: *mut u8, _size: usize) -> bool {
+    false
+}
+
+pub fn can_release_part(_flags: u32) -> bool {
+    false
+}
+
+#[cfg(feature = "global")]
+pub fn acquire_global_lock() {
+    compile_error!("The `global` feature is not implemented for the SGX platform")
+}
+
+#[cfg(feature = "global")]
+pub fn release_global_lock() {
+    compile_error!("The `global` feature is not implemented for the SGX platform")
+}
+
+pub fn allocates_zeros() -> bool {
+    false
+}
+
+pub fn page_size() -> usize {
+    0x1000
+}