mprotect system call exposed to the untrusted code.

src/untrusted/irt/irt.h

 /*
  * Copyright (c) 2012 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_UNTRUSTED_IRT_IRT_H_
 #define NATIVE_CLIENT_SRC_UNTRUSTED_IRT_IRT_H_
 
 #include <stddef.h>
 #include <sys/types.h>
@@ skipping 69 matching lines @@
   int (*getdents)(int fd, struct dirent *, size_t count, size_t *nread);
 };
 
 #define NACL_IRT_FILENAME_v0_1      "nacl-irt-filename-0.1"
 struct nacl_irt_filename {
   int (*open)(const char *pathname, int oflag, mode_t cmode, int *newfd);
   int (*stat)(const char *pathname, struct stat *);
 };
 
 #define NACL_IRT_MEMORY_v0_1    "nacl-irt-memory-0.1"
+#define NACL_IRT_MEMORY_v0_2    "nacl-irt-memory-0.2"
 struct nacl_irt_memory {
   int (*sysbrk)(void **newbrk);
   int (*mmap)(void **addr, size_t len, int prot, int flags, int fd, off_t off);
   int (*munmap)(void *addr, size_t len);
+  int (*mprotect)(void *addr, size_t len, int prot);

[Mark Seaborn, 2012/10/18 00:27:23]

Modifying struct nacl_irt_memory in-place means we've lost the information that
v0_1 didn't include mprotect().  I don't like that.  I think we should retain
that information in the headers as documentation in some way.

[bsy, 2012/10/18 19:46:09]

the pattern should be something like:

struct nacl_irt_memory {
  int (*sysbrk)(...);
  int (*mmap)(...);
  int (*munmap)(...);
};

struct nacl_irt_memory_v0_2 {
  struct nacl_irt_memory base;
  int (*mprotect)(...);
};

so information that the new version of the interface is a strict extension of
the older one is obvious.  if we were willing to use --fms-extensions or
-fplan9-extensions, "base" could be elided.

 };
 
 #define NACL_IRT_DYNCODE_v0_1   "nacl-irt-dyncode-0.1"
 struct nacl_irt_dyncode {
   int (*dyncode_create)(void *dest, const void *src, size_t size);
   int (*dyncode_modify)(void *dest, const void *src, size_t size);
   int (*dyncode_delete)(void *dest, size_t size);
 };
 
 #define NACL_IRT_THREAD_v0_1   "nacl-irt-thread-0.1"
@@ skipping 87 matching lines @@
                            NaClExceptionHandler *old_handler);
   int (*exception_stack)(void *stack, size_t size);
   int (*exception_clear_flag)(void);
 };
 
 #if defined(__cplusplus)
 }
 #endif
 
 #endif /* NATIVE_CLIENT_SRC_UNTRUSTED_IRT_IRT_H */