Split NaCl SFI and non-SFI helpers into separate processes

With this change, NaCl SFI and non-SFI processes now run in disjoint
PID namespaces, so the kernel should prevent sending signals from an SFI
process to a non-SFI process, or vice versa.  (The NaCl PID namespaces
are still nested within the renderer's PID namespace though.)

BUG=364945
NOTRY=true

Review URL: https://codereview.chromium.org/279693002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270244 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 42 insertions, 0 deletions

diff --git a/components/nacl/common/nacl_nonsfi_util.cc b/components/nacl/common/nacl_nonsfi_util.cc
new file mode 100644
index 0000000..d56cea6
--- /dev/null
+++ b/components/nacl/common/nacl_nonsfi_util.cc
@@ -0,0 +1,24 @@
+// Copyright 2014 The Chromium 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 "components/nacl/common/nacl_nonsfi_util.h"
+
+#include "base/command_line.h"
+#include "build/build_config.h"
+#include "components/nacl/common/nacl_switches.h"
+
+namespace nacl {
+
+bool IsNonSFIModeEnabled() {
+#if defined(OS_CHROMEOS) && defined(ARCH_CPU_ARMEL)
+  return true;
+#elif defined(OS_LINUX)
+  return CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableNaClNonSfiMode);
+#else
+  return false;
+#endif
+}
+
+}  // namespace nacl
diff --git a/components/nacl/common/nacl_nonsfi_util.h b/components/nacl/common/nacl_nonsfi_util.h
new file mode 100644
index 0000000..07c033f
--- /dev/null
+++ b/components/nacl/common/nacl_nonsfi_util.h
@@ -0,0 +1,18 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_NACL_COMMON_NACL_NONSFI_UTIL_H_
+#define COMPONENTS_NACL_COMMON_NACL_NONSFI_UTIL_H_
+
+namespace nacl {
+
+// Returns true if non-SFI mode *can* run on the current platform and if non-SFI
+// manifest entries are preferred.  There can be other restrictions which
+// prevent a particular module from launching.  See NaClProcessHost::Launch
+// which makes the final determination.
+bool IsNonSFIModeEnabled();
+
+}  // namespace nacl
+
+#endif  // COMPONENTS_NACL_COMMON_NACL_NONSFI_UTIL_H_