I am somewhat reluctantly changing the API so that setProcFD is no longer

sandbox_impl.h

 // Copyright (c) 2010 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_IMPL_H__
 #define SANDBOX_IMPL_H__
 
 #include <asm/ldt.h>
 #include <errno.h>
 #include <fcntl.h>
@@ skipping 61 matching lines @@
   // This could be because the kernel does not support Seccomp mode, or it
   // could be because we fail to successfully rewrite all system call entry
   // points.
   // "proc" should be a file descriptor for "/proc", or -1 if not provided by
   // the caller.
   static int supportsSeccompSandbox(int proc)
                                          asm("SupportsSeccompSandbox");
 
   // The sandbox needs to be able to access "/proc/self/maps". If this file
   // is not accessible when "startSandbox()" gets called, the caller can
-  // provide an already opened file descriptor by calling "setProcSelf()".
+  // provide an already opened file descriptor by calling "setProcFd()".
   // The sandbox becomes the newer owner of this file descriptor and will
-  // eventually close it when "startSandbox()" executes. But if the caller
-  // never ends up calling startSandbox(), then the caller must close the
-  // file descriptor.
+  // eventually close it. After calling setProcFd(), the caller MUST eventually
+  // call startSandbox(), or resources could be leaked.
   static void setProcFd(int proc)        asm("SeccompSandboxSetProcFd");
 
   // This is the main public entry point. It finds all system calls that
   // need rewriting, sets up the resources needed by the sandbox, and
   // enters Seccomp mode.
   static void startSandbox()             asm("StartSeccompSandbox");
 
   // TODO(mseaborn): Consider re-instating this declaration.
   // private:
 
@@ skipping 585 matching lines @@
 extern struct SandboxPolicy g_policy;
 
 typedef void (*CreateTrustedThreadFunc)(SecureMem::Args* secureMem);
 extern CreateTrustedThreadFunc g_create_trusted_thread;
 
 } // namespace
 
 using playground::Sandbox;
 
 #endif // SANDBOX_IMPL_H__