MinSFI: Add loader

src/minsfi/trusted/state.c

+/*
+ * Copyright (c) 2014 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include <string.h>
+
+#include "native_client/src/include/minsfi_priv.h"
+
+/*
+ * This is the memory base variable which the SFI-sandboxed pointers are
+ * treated relative to. It is defined in the trusted runtime, exported and then
+ * imported by the untrusted code via the compiler transforms. It is a 64-bit
+ * unsigned integer on both 32-bit and 64-bit platforms. See comments in the
+ * SandboxMemoryAccesses MinSFI LLVM pass for more details.
+ */
+uint64_t __sfi_memory_base = 0;
+
+static MinsfiSandbox ActiveSandbox = { .mem_base = NULL };
+
+const MinsfiSandbox *MinsfiGetActiveSandbox(void) {
+  if (ActiveSandbox.mem_base != NULL)
+    return &ActiveSandbox;
+  else
+    return NULL;
+}
+
+void MinsfiSetActiveSandbox(const MinsfiSandbox *sb) {
+  if (sb != NULL)
+    memcpy(&ActiveSandbox, sb, sizeof(MinsfiSandbox));
+  else
+    ActiveSandbox.mem_base = NULL;
+
+  __sfi_memory_base = (uintptr_t) ActiveSandbox.mem_base;
+}