Start all children in their own PID namespace.

sandbox/linux/services/credentials.h

 // Copyright (c) 2013 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 SANDBOX_LINUX_SERVICES_CREDENTIALS_H_
 #define SANDBOX_LINUX_SERVICES_CREDENTIALS_H_
 
 #include "build/build_config.h"
 // Link errors are tedious to track, raise a compile-time error instead.
 #if defined(OS_ANDROID)
@@ skipping 31 matching lines @@
   // the caller.
   static bool DropAllCapabilities(int proc_fd) WARN_UNUSED_RESULT;
   // A similar API which assumes that it can open /proc/self/ by itself.
   static bool DropAllCapabilities() WARN_UNUSED_RESULT;
   // Sets the effective and permitted capability sets for the current thread to
   // the list of capabiltiies in |caps|. All other capability flags are cleared.
   static bool SetCapabilities(int proc_fd,
                               const std::vector<LinuxCapability>& caps)
       WARN_UNUSED_RESULT;
 
+  // Versions of the above functions which do not check that the process is
+  // single-threaded. After calling these functions, capabilities of other
+  // threads will not be changed.
+  static bool DropAllCapabilitiesOnCurrentThread() WARN_UNUSED_RESULT;
+  static bool SetCapabilitiesOnCurrentThread(
+      const std::vector<LinuxCapability>& caps) WARN_UNUSED_RESULT;
+
   // Returns true if the current thread has either the effective, permitted, or
   // inheritable flag set for the given capability.
   static bool HasCapability(LinuxCapability cap);
 
   // Return true iff there is any capability in any of the capabilities sets
   // of the current thread.
   static bool HasAnyCapability();
 
   // Returns whether the kernel supports CLONE_NEWUSER and whether it would be
   // possible to immediately move to a new user namespace. There is no point
@@ skipping 25 matching lines @@
   //   - DropAllCapabilities() must be called to prevent escapes.
   static bool DropFileSystemAccess(int proc_fd) WARN_UNUSED_RESULT;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Credentials);
 };
 
 }  // namespace sandbox.
 
 #endif  // SANDBOX_LINUX_SERVICES_CREDENTIALS_H_