Use raw-dylib, remove fake VDSO

intel-sgx/enclave-runner/Cargo.toml

@@ -15,8 +15,6 @@ documentation = "https://edp.fortanix.com/docs/api/enclave_runner/"
 homepage = "https://edp.fortanix.com/"
 keywords = ["sgx", "enclave"]
 categories = ["os", "hardware-support"]
-build = "build.rs"
-exclude = ["fake-vdso/.gitignore", "fake-vdso/Makefile", "fake-vdso/main.S"]
 
 [dependencies]
 # Project dependencies

intel-sgx/enclave-runner/src/lib.rs

@@ -4,7 +4,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#![allow(non_local_definitions)] // Required by failure
+#![feature(raw_dylib_elf)]
+#![allow(non_local_definitions, incomplete_features)] // Required by failure
 #![deny(warnings)]
 #![doc(
     html_logo_url = "https://edp.fortanix.com/img/docs/edp-logo.svg",

intel-sgx/enclave-runner/src/tcs.rs

@@ -48,6 +48,11 @@ impl<T: Tcs> Usercall<T> {
     }
 }
 
+#[link(name = "linux-vdso.so.1", kind = "raw-dylib", modifiers = "+verbatim")]
+unsafe extern "C" {
+    fn __vdso_sgx_enter_enclave();
+}
+
 pub(crate) fn coenter<T: Tcs>(
     tcs: T,
     mut p1: u64,
@@ -67,18 +72,6 @@ pub(crate) fn coenter<T: Tcs>(
 .weak __vdso_sgx_enter_enclave
 .type __vdso_sgx_enter_enclave, function
                 mov __vdso_sgx_enter_enclave@GOTPCREL(%rip), {}
-                jmp 1f
-
-                // Strongly link to another symbol in the VDSO, so that the
-                // linker will include a DT_NEEDED entry for `linux-vdso.so.1`.
-                // This doesn't happen automatically because rustc passes
-                // `--as-needed` to the linker. This is never executed because
-                // of the unconditional jump above.
-.global __vdso_clock_gettime
-.type __vdso_clock_gettime, function
-                call __vdso_clock_gettime@PLT
-
-1:
                 ", out(reg) addr, options(nomem, nostack, att_syntax));
             addr != 0
         }