From 1ecf0eab9181cad646f5859c78c45ff5568a5f7d Mon Sep 17 00:00:00 2001
From: Avril <flanchan@cumallover.me>
Date: Mon, 22 Mar 2021 23:21:52 +0000
Subject: [PATCH] added clflush after explicit_bzero on x86 nightly builds

---
 Cargo.toml    |  3 +++
 build.rs      | 24 ++++++++++++++++++++++++
 src/lib.rs    |  2 ++
 src/stream.rs |  8 ++++++++
 4 files changed, 37 insertions(+)
 create mode 100644 build.rs

diff --git a/Cargo.toml b/Cargo.toml
index ba99f99..9647fc0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,3 +17,6 @@ base64 = "0.13"
 getrandom = "0.2"
 openssl = "0.10"
 smallvec = {version = "1.6", features=["union"], optional = true}
+
+[build-dependencies]
+rustc_version = "0.2"
diff --git a/build.rs b/build.rs
new file mode 100644
index 0000000..6399463
--- /dev/null
+++ b/build.rs
@@ -0,0 +1,24 @@
+
+extern crate rustc_version;
+use rustc_version::{version, version_meta, Channel};
+
+fn main() {
+    // Assert we haven't travelled back in time
+    assert!(version().unwrap().major >= 1);
+
+    // Set cfg flags depending on release channel
+    match version_meta().unwrap().channel {
+        Channel::Stable => {
+            println!("cargo:rustc-cfg=stable");
+        }
+        Channel::Beta => {
+            println!("cargo:rustc-cfg=beta");
+        }
+        Channel::Nightly => {
+            println!("cargo:rustc-cfg=nightly");
+        }
+        Channel::Dev => {
+            println!("cargo:rustc-cfg=dev");
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 710995f..21cae37 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(nightly, feature(asm))] 
+
 #![allow(dead_code)]
 
 //extern crate test;
diff --git a/src/stream.rs b/src/stream.rs
index d29eb45..09581f1 100644
--- a/src/stream.rs
+++ b/src/stream.rs
@@ -128,6 +128,14 @@ where W: Write
 	    }
 	    unsafe {
 		explicit_bzero(self.buffer.as_mut_ptr() as *mut c_void, self.buffer.len());
+
+		#[cfg(nightly)] 
+		if cfg!(target_arch = "x86_64") || cfg!(target_arch = "x86"){
+		    asm!(
+			"clflush [{}]",
+			in(reg) self.buffer.as_mut_ptr()
+		    );
+		}
 	    }
 	    return;
 	}