MinSFI: Passing arguments to the entry function

src/include/minsfi_priv.h

 /*
  * 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.
  */
 
 #ifndef NATIVE_CLIENT_SRC_INCLUDE_MINSFI_PRIV_H_
 #define NATIVE_CLIENT_SRC_INCLUDE_MINSFI_PRIV_H_
 
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <unistd.h>
 
+/* Definition of the untrusted pointer type */

[jvoung (off chromium), 2014/09/10 17:04:29]

It seems more like this is analogous to uintptr_t -- an integer type capable of
holding a value converted from an untrusted pointer, and can be converted back
without loss of information, etc.

[dbrazdil, 2014/09/10 18:49:47]

Done.

+typedef uint32_t sfiptr_t;
+
 typedef struct {
   uint32_t ptr_size;               /* size of sandboxed pointers in bits */
   uint32_t dataseg_offset;

[jvoung (off chromium), 2014/09/10 17:04:29]

should this be an sfiptr_t also?

[dbrazdil, 2014/09/10 18:49:47]

I thought about that and I see how it would make sense, but the value is not
used in the same context. It's only used by GenerateMemoryLayout to compute the
bounds of the individual memory regions and is never actually added to a base.
That's the job of layout.dataseg.offset

   uint32_t dataseg_size;
   const char *dataseg_template;
 } MinsfiManifest;
 
 typedef struct {
-  uint32_t offset;
+  sfiptr_t offset;
   uint32_t length;
 } MinsfiMemoryRegion;
 
 typedef struct {
   MinsfiMemoryRegion dataseg;
   MinsfiMemoryRegion heap;
   MinsfiMemoryRegion stack;
 } MinsfiMemoryLayout;
 
 typedef struct {
   char *mem_base;
   uint64_t mem_alloc_size;
-  uint32_t ptr_mask;
+  sfiptr_t ptr_mask;
   MinsfiMemoryLayout mem_layout;
 } MinsfiSandbox;
 
 /*
  * Computes the boundaries of the individual regions of the sandbox's address
  * subspace and stores them into the given minsfi_layout data structure.
  * Returns FALSE if a layout cannot be created for the given parameters.
  */
 bool MinsfiGenerateMemoryLayout(const MinsfiManifest *manifest,
                                 uint32_t page_size, MinsfiMemoryLayout *layout);
@@ skipping 20 matching lines @@
  */
 const MinsfiSandbox *MinsfiGetActiveSandbox(void);
 
 /*
  * Sets the sandbox which all trampolines will refer to. Internally copies the
  * data structure to its own storage.
  */
 void MinsfiSetActiveSandbox(const MinsfiSandbox *sb);
 
 #endif  // NATIVE_CLIENT_SRC_INCLUDE_MINSFI_PRIV_H_