Enable ASLR for windows-gnu

Author: mati865

compiler/rustc_target/src/spec/windows_gnu_base.rs

@@ -11,6 +11,10 @@ pub fn opts() -> TargetOptions {
             "-fno-use-linker-plugin".to_string(),
             // Always enable DEP (NX bit) when it is available
             "-Wl,--nxcompat".to_string(),
+            // Enable ASLR
+            "-Wl,--dynamicbase".to_string(),
+            // ASLR will rebase it anyway so leaving that option enabled only leads to confusion
+            "-Wl,--disable-auto-image-base".to_string(),
         ],
     );
 

compiler/rustc_target/src/spec/x86_64_pc_windows_gnu.rs

@@ -3,7 +3,10 @@ use crate::spec::{LinkerFlavor, LldFlavor, Target, TargetResult};
 pub fn target() -> TargetResult {
     let mut base = super::windows_gnu_base::opts();
     base.cpu = "x86-64".to_string();
-    base.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap().push("-m64".to_string());
+    let gcc_pre_link_args = base.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap();
+    gcc_pre_link_args.push("-m64".to_string());
+    // Use high-entropy 64 bit address space for ASLR
+    gcc_pre_link_args.push("-Wl,--high-entropy-va".to_string());
     base.pre_link_args
         .insert(LinkerFlavor::Lld(LldFlavor::Ld), vec!["-m".to_string(), "i386pep".to_string()]);
     base.max_atomic_width = Some(64);

compiler/rustc_target/src/spec/x86_64_uwp_windows_gnu.rs

@@ -3,7 +3,10 @@ use crate::spec::{LinkerFlavor, LldFlavor, Target, TargetResult};
 pub fn target() -> TargetResult {
     let mut base = super::windows_uwp_gnu_base::opts();
     base.cpu = "x86-64".to_string();
-    base.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap().push("-m64".to_string());
+    let gcc_pre_link_args = base.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap();
+    gcc_pre_link_args.push("-m64".to_string());
+    // Use high-entropy 64 bit address space for ASLR
+    gcc_pre_link_args.push("-Wl,--high-entropy-va".to_string());
     base.pre_link_args
         .insert(LinkerFlavor::Lld(LldFlavor::Ld), vec!["-m".to_string(), "i386pep".to_string()]);
     base.max_atomic_width = Some(64);