Beispiel #1
0
/* this function was automagically generated */
static int32_t NaClSysMunmapDecoder(struct NaClAppThread *natp) {
  struct NaClSysMunmapArgs {
    uint32_t start;
    uint32_t length;
  } p = *(struct NaClSysMunmapArgs *) natp->syscall_args;

  // ### temporary disabled
  /* d'b: disable user free() */
//  return NACL_ABI_EFAULT;
  /* d'b end */

  return NaClSysMunmap(natp, (void *) (uintptr_t) p.start, (size_t)  p.length);
}
int main(int argc, char **argv) {
  char *nacl_file;
  struct GioMemoryFileSnapshot gf;
  struct NaClApp state;
  struct NaClAppThread nat, *natp = &nat;
  int errcode;
  uint32_t initial_addr;
  uint32_t addr;
  struct NaClVmmap *mem_map;
  char *nacl_verbosity = getenv("NACLVERBOSITY");

  if (argc < 2) {
    printf("No nexe file!\n\nFAIL\n");
  }
  nacl_file = argv[1];

  NaClLogModuleInit();

  NaClLogSetVerbosity((NULL == nacl_verbosity)
                      ? 0
                      : strtol(nacl_verbosity, (char **) 0, 0));

  errcode = GioMemoryFileSnapshotCtor(&gf, nacl_file);
  ASSERT_NE(errcode, 0);
  errcode = NaClAppCtor(&state);
  ASSERT_NE(errcode, 0);
  errcode = NaClAppLoadFile((struct Gio *) &gf,
                            &state,
                            NACL_ABI_CHECK_OPTION_CHECK);
  ASSERT_EQ(errcode, 0);

  InitThread(&state, natp);

  /*
   * Initial mappings:
   * 0. --  Zero page
   * 1. rx  Static code segment
   * 2. r   Read-only data segment
   * 3. rw  Writable data segment
   * 4. rw  Stack
   * There is no dynamic code area in this case.
   */
  /* Check the initial mappings. */
  mem_map = &state.mem_map;
  ASSERT_EQ(mem_map->nvalid, 5);
  CheckLowerMappings(mem_map);

  /* Allocate range */
  addr = NaClSysMmap(natp, 0, 3 * NACL_MAP_PAGESIZE,
                     NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                     NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                     -1, 0);
  printf("addr=0x%"NACL_PRIx32"\n", addr);
  initial_addr = addr;
  /*
   * The mappings have changed to become:
   * 0. --  Zero page
   * 1. rx  Static code segment
   * 2. r   Read-only data segment
   * 3. rw  Writable data segment
   * 4. rw  mmap()'d anonymous, 3 pages (new)
   * 5. rw  Stack
   */

  /* Map to overwrite the start of the previously allocated range */
  addr = NaClSysMmap(natp, (void *) (uintptr_t) initial_addr,
                     2 * NACL_MAP_PAGESIZE,
                     NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                     NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE
                     | NACL_ABI_MAP_FIXED,
                     -1, 0);
  printf("addr=0x%"NACL_PRIx32"\n", addr);
  ASSERT_EQ(addr, initial_addr);
  /*
   * The mappings have changed to become:
   * 0. --  Zero page
   * 1. rx  Static code segment
   * 2. r   Read-only data segment
   * 3. rw  Writable data segment
   * 4. rw  mmap()'d anonymous, 2 pages (new)
   * 5. rw  mmap()'d anonymous, 1 pages (previous)
   * 6. rw  Stack
   */

  /* Allocate new page */
  addr = NaClSysMmap(natp, 0, NACL_MAP_PAGESIZE,
                     NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                     NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                     -1, 0);
  printf("addr=0x%"NACL_PRIx32"\n", addr);
  /*
   * Our allocation strategy is to scan down from stack.  This is an
   * implementation detail and not part of the guaranteed semantics,
   * but it is good to test that what we expect of our implementation
   * didn't change.
   */
  ASSERT_EQ_MSG(addr, initial_addr - NACL_MAP_PAGESIZE,
                "Allocation strategy changed!");
  /*
   * The mappings have changed to become:
   * 0. --  Zero page
   * 1. rx  Static code segment
   * 2. r   Read-only data segment
   * 3. rw  Writable data segment
   * 4. rw  mmap()'d anonymous, 1 pages (new)
   * 5. rw  mmap()'d anonymous, 2 pages
   * 6. rw  mmap()'d anonymous, 1 pages
   * 7. rw  Stack
   */

  NaClVmmapMakeSorted(mem_map);
  ASSERT_EQ(mem_map->nvalid, 8);
  CheckLowerMappings(mem_map);
  NaClVmmapDebug(mem_map, "After allocations");
  /* Skip mappings 0, 1, 2 and 3. */
  ASSERT_EQ(mem_map->vmentry[4]->page_num,
            (initial_addr - NACL_MAP_PAGESIZE) >> NACL_PAGESHIFT);
  ASSERT_EQ(mem_map->vmentry[4]->npages,
            NACL_PAGES_PER_MAP);

  ASSERT_EQ(mem_map->vmentry[5]->page_num,
            initial_addr >> NACL_PAGESHIFT);
  ASSERT_EQ(mem_map->vmentry[5]->npages,
            2 * NACL_PAGES_PER_MAP);

  ASSERT_EQ(mem_map->vmentry[6]->page_num,
            (initial_addr +  2 * NACL_MAP_PAGESIZE) >> NACL_PAGESHIFT);
  ASSERT_EQ(mem_map->vmentry[6]->npages,
            NACL_PAGES_PER_MAP);

  /*
   * Undo effects of previous mmaps
   */
  errcode = NaClSysMunmap(natp,
                          (void *) (uintptr_t) (initial_addr
                                                - NACL_MAP_PAGESIZE),
                          NACL_MAP_PAGESIZE * 4);
  ASSERT_EQ(errcode, 0);
  /*
   * Mappings return to being:
   * 0. --  Zero page
   * 1. rx  Static code segment
   * 2. r   Read-only data segment
   * 3. rw  Writable data segment
   * 4. rw  Stack
   */
  ASSERT_EQ(mem_map->nvalid, 5);
  CheckLowerMappings(mem_map);


  /* Allocate range */
  addr = NaClSysMmap(natp, 0, 9 * NACL_MAP_PAGESIZE,
                     NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                     NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE, -1, 0);
  printf("addr=0x%"NACL_PRIx32"\n", addr);
  initial_addr = addr;
  /*
   * The mappings have changed to become:
   * 0. --  Zero page
   * 1. rx  Static code segment
   * 2. r   Read-only data segment
   * 3. rw  Writable data segment
   * 4. rw  mmap()'d anonymous, 9 pages (new)
   * 5. rw  Stack
   */

  /* Map into middle of previously allocated range */
  addr = NaClSysMmap(natp,
                     (void *) (uintptr_t) (initial_addr
                                           + 2 * NACL_MAP_PAGESIZE),
                     3 * NACL_MAP_PAGESIZE,
                     NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                     NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE
                     | NACL_ABI_MAP_FIXED,
                     -1, 0);
  printf("addr=0x%"NACL_PRIx32"\n", addr);
  ASSERT_EQ(addr, initial_addr + NACL_MAP_PAGESIZE * 2);
  /*
   * The mappings have changed to become:
   * 0. --  Zero page
   * 1. rx  Static code segment
   * 2. r   Read-only data segment
   * 3. rw  Writable data segment
   * 4. rw  mmap()'d anonymous, 2 pages (previous)
   * 5. rw  mmap()'d anonymous, 3 pages (new)
   * 6. rw  mmap()'d anonymous, 4 pages (previous)
   * 7. rw  Stack
   */

  NaClVmmapMakeSorted(mem_map);
  ASSERT_EQ(mem_map->nvalid, 8);
  CheckLowerMappings(mem_map);

  ASSERT_EQ(mem_map->vmentry[4]->page_num,
            initial_addr >> NACL_PAGESHIFT);
  ASSERT_EQ(mem_map->vmentry[4]->npages,
            2 * NACL_PAGES_PER_MAP);

  ASSERT_EQ(mem_map->vmentry[5]->page_num,
            (initial_addr + 2 * NACL_MAP_PAGESIZE) >> NACL_PAGESHIFT);
  ASSERT_EQ(mem_map->vmentry[5]->npages,
            3 * NACL_PAGES_PER_MAP);

  ASSERT_EQ(mem_map->vmentry[6]->page_num,
            (initial_addr + 5 * NACL_MAP_PAGESIZE) >> NACL_PAGESHIFT);
  ASSERT_EQ(mem_map->vmentry[6]->npages,
            4 * NACL_PAGES_PER_MAP);

  /*
   * Undo effects of previous mmaps
   */
  errcode = NaClSysMunmap(natp, (void *) (uintptr_t) initial_addr,
                          9 * NACL_MAP_PAGESIZE);
  ASSERT_EQ(errcode, 0);
  ASSERT_EQ(mem_map->nvalid, 5);
  CheckLowerMappings(mem_map);
  /*
   * Mappings return to being:
   * 0. --  Zero page
   * 1. rx  Static code segment
   * 2. r   Read-only data segment
   * 3. rw  Writable data segment
   * 4. rw  Stack
   */

  /*
   * Check use of hint.
   */
  addr = NaClSysMmap(natp, (void *) (uintptr_t) initial_addr,
                     NACL_MAP_PAGESIZE,
                     NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                     NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                     -1, 0);
  ASSERT_LE(addr, 0xffff0000u);
  printf("addr=0x%"NACL_PRIx32"\n", addr);
  ASSERT_LE_MSG(initial_addr, addr, "returned address not at or above hint");
  errcode = NaClSysMunmap(natp, (void *) (uintptr_t) addr, NACL_MAP_PAGESIZE);
  ASSERT_EQ(errcode, 0);

  /* Check handling of zero-sized mappings. */
  addr = NaClSysMmap(natp, 0, 0,
                     NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                     NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE, -1, 0);
  ASSERT_EQ((int) addr, -NACL_ABI_EINVAL);

  errcode = NaClSysMunmap(natp, (void *) (uintptr_t) initial_addr, 0);
  ASSERT_EQ(errcode, -NACL_ABI_EINVAL);

  printf("PASS\n");
  return 0;
}
Beispiel #3
0
int main(int argc, char **argv) {
    char *nacl_file;
    struct NaClApp state;
    struct NaClApp *nap = &state;
    struct NaClAppThread nat, *natp = &nat;
    int errcode;
    uint32_t initial_addr;
    uint32_t addr;
    struct NaClVmmap *mem_map;
    struct NaClVmmapEntry *ent;
    char *nacl_verbosity = getenv("NACLVERBOSITY");

    NaClHandleBootstrapArgs(&argc, &argv);

    if (argc < 2) {
        printf("No nexe file!\n\nFAIL\n");
    }
    nacl_file = argv[1];

    NaClAllModulesInit();

    NaClLogSetVerbosity((NULL == nacl_verbosity)
                        ? 0
                        : strtol(nacl_verbosity, (char **) 0, 0));

    errcode = NaClAppCtor(&state);
    ASSERT_NE(errcode, 0);
    errcode = NaClAppLoadFileFromFilename(nap, nacl_file);
    ASSERT_EQ(errcode, LOAD_OK);

    InitThread(&state, natp);

    /*
     * Initial mappings:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  Stack
     * There is no dynamic code area in this case.
     */
    /* Check the initial mappings. */
    mem_map = &state.mem_map;
    ASSERT_EQ(mem_map->nvalid, 5);
    CheckLowerMappings(mem_map);

    /* Allocate range */
    addr = NaClSysMmapIntern(nap, 0, 3 * NACL_MAP_PAGESIZE,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                             -1, 0);
    printf("addr=0x%"NACL_PRIx32"\n", addr);
    initial_addr = addr;
    /*
     * The mappings have changed to become:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  mmap()'d anonymous, 3 pages (new)
     * 5. rw  Stack
     */

    /* Map to overwrite the start of the previously allocated range */
    addr = NaClSysMmapIntern(nap, (void *) (uintptr_t) initial_addr,
                             2 * NACL_MAP_PAGESIZE,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE
                             | NACL_ABI_MAP_FIXED,
                             -1, 0);
    printf("addr=0x%"NACL_PRIx32"\n", addr);
    ASSERT_EQ(addr, initial_addr);
    /*
     * The mappings have changed to become:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  mmap()'d anonymous, 2 pages (new)
     * 5. rw  mmap()'d anonymous, 1 pages (previous)
     * 6. rw  Stack
     */

    /* Allocate new page */
    addr = NaClSysMmapIntern(nap, 0, NACL_MAP_PAGESIZE,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                             -1, 0);
    printf("addr=0x%"NACL_PRIx32"\n", addr);
    /*
     * Our allocation strategy is to scan down from stack.  This is an
     * implementation detail and not part of the guaranteed semantics,
     * but it is good to test that what we expect of our implementation
     * didn't change.
     */
    ASSERT_EQ_MSG(addr, initial_addr - NACL_MAP_PAGESIZE,
                  "Allocation strategy changed!");
    /*
     * The mappings have changed to become:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  mmap()'d anonymous, 1 pages (new)
     * 5. rw  mmap()'d anonymous, 2 pages
     * 6. rw  mmap()'d anonymous, 1 pages
     * 7. rw  Stack
     */

    NaClVmmapMakeSorted(mem_map);
    ASSERT_EQ(mem_map->nvalid, 8);
    CheckLowerMappings(mem_map);
    NaClVmmapDebug(mem_map, "After allocations");
    /* Skip mappings 0, 1, 2 and 3. */
    ASSERT_EQ(mem_map->vmentry[4]->page_num,
              (initial_addr - NACL_MAP_PAGESIZE) >> NACL_PAGESHIFT);
    ASSERT_EQ(mem_map->vmentry[4]->npages,
              NACL_PAGES_PER_MAP);

    ASSERT_EQ(mem_map->vmentry[5]->page_num,
              initial_addr >> NACL_PAGESHIFT);
    ASSERT_EQ(mem_map->vmentry[5]->npages,
              2 * NACL_PAGES_PER_MAP);

    ASSERT_EQ(mem_map->vmentry[6]->page_num,
              (initial_addr +  2 * NACL_MAP_PAGESIZE) >> NACL_PAGESHIFT);
    ASSERT_EQ(mem_map->vmentry[6]->npages,
              NACL_PAGES_PER_MAP);

    /*
     * Undo effects of previous mmaps
     */
    errcode = NaClSysMunmap(natp,
                            (void *) (uintptr_t) (initial_addr
                                    - NACL_MAP_PAGESIZE),
                            NACL_MAP_PAGESIZE * 4);
    ASSERT_EQ(errcode, 0);
    /*
     * Mappings return to being:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  Stack
     */
    ASSERT_EQ(mem_map->nvalid, 5);
    CheckLowerMappings(mem_map);


    /* Allocate range */
    addr = NaClSysMmapIntern(nap, 0, 9 * NACL_MAP_PAGESIZE,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                             -1, 0);
    printf("addr=0x%"NACL_PRIx32"\n", addr);
    initial_addr = addr;
    /*
     * The mappings have changed to become:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  mmap()'d anonymous, 9 pages (new)
     * 5. rw  Stack
     */

    /* Map into middle of previously allocated range */
    addr = NaClSysMmapIntern(nap,
                             (void *) (uintptr_t) (initial_addr
                                     + 2 * NACL_MAP_PAGESIZE),
                             3 * NACL_MAP_PAGESIZE,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE
                             | NACL_ABI_MAP_FIXED,
                             -1, 0);
    printf("addr=0x%"NACL_PRIx32"\n", addr);
    ASSERT_EQ(addr, initial_addr + NACL_MAP_PAGESIZE * 2);
    /*
     * The mappings have changed to become:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  mmap()'d anonymous, 2 pages (previous)
     * 5. rw  mmap()'d anonymous, 3 pages (new)
     * 6. rw  mmap()'d anonymous, 4 pages (previous)
     * 7. rw  Stack
     */

    NaClVmmapMakeSorted(mem_map);
    ASSERT_EQ(mem_map->nvalid, 8);
    CheckLowerMappings(mem_map);

    ASSERT_EQ(mem_map->vmentry[4]->page_num,
              initial_addr >> NACL_PAGESHIFT);
    ASSERT_EQ(mem_map->vmentry[4]->npages,
              2 * NACL_PAGES_PER_MAP);

    ASSERT_EQ(mem_map->vmentry[5]->page_num,
              (initial_addr + 2 * NACL_MAP_PAGESIZE) >> NACL_PAGESHIFT);
    ASSERT_EQ(mem_map->vmentry[5]->npages,
              3 * NACL_PAGES_PER_MAP);

    ASSERT_EQ(mem_map->vmentry[6]->page_num,
              (initial_addr + 5 * NACL_MAP_PAGESIZE) >> NACL_PAGESHIFT);
    ASSERT_EQ(mem_map->vmentry[6]->npages,
              4 * NACL_PAGES_PER_MAP);


    /* Change the memory protection of previously allocated range */
    errcode = NaClSysMprotectInternal(nap, (initial_addr
                                            + 1 * NACL_MAP_PAGESIZE),
                                      5 * NACL_MAP_PAGESIZE,
                                      NACL_ABI_PROT_READ);
    ASSERT_EQ(errcode, 0);
    /*
     * The mappings have changed to become:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  mmap()'d anonymous, 1 pages (previous)
     * 5. r   mmap()'d anonymous, 1 pages (new)
     * 6. r   mmap()'d anonymous, 3 pages (new)
     * 7. r   mmap()'d anonymous, 1 pages (new)
     * 8. rw  mmap()'d anonymous, 3 pages (previous)
     * 9. rw  Stack
     */

    NaClVmmapMakeSorted(mem_map);
    ASSERT_EQ(mem_map->nvalid, 10);
    CheckLowerMappings(mem_map);

    ASSERT_EQ(mem_map->vmentry[4]->npages,
              1 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[4]->prot,
              NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE);

    ASSERT_EQ(mem_map->vmentry[5]->npages,
              1 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[5]->prot,
              NACL_ABI_PROT_READ);

    ASSERT_EQ(mem_map->vmentry[6]->npages,
              3 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[6]->prot,
              NACL_ABI_PROT_READ);

    ASSERT_EQ(mem_map->vmentry[7]->npages,
              1 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[7]->prot,
              NACL_ABI_PROT_READ);

    ASSERT_EQ(mem_map->vmentry[8]->npages,
              3 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[8]->prot,
              NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE);


    /* Change the memory protection of previously allocated range */
    errcode = NaClSysMprotectInternal(nap, (initial_addr
                                            + 2 * NACL_MAP_PAGESIZE),
                                      3 * NACL_MAP_PAGESIZE,
                                      NACL_ABI_PROT_NONE);
    ASSERT_EQ(errcode, 0);
    /*
     * The mappings have changed to become:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  mmap()'d anonymous, 1 pages (previous)
     * 5. r   mmap()'d anonymous, 1 pages (previous)
     * 6. --  mmap()'d anonymous, 3 pages (new)
     * 7. r   mmap()'d anonymous, 1 pages (previous)
     * 8. rw  mmap()'d anonymous, 3 pages (previous)
     * 9. rw  Stack
     */

    NaClVmmapMakeSorted(mem_map);
    ASSERT_EQ(mem_map->nvalid, 10);
    CheckLowerMappings(mem_map);

    ASSERT_EQ(mem_map->vmentry[4]->npages,
              1 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[4]->prot,
              NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE);

    ASSERT_EQ(mem_map->vmentry[5]->npages,
              1 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[5]->prot,
              NACL_ABI_PROT_READ);

    ASSERT_EQ(mem_map->vmentry[6]->npages,
              3 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[6]->prot,
              NACL_ABI_PROT_NONE);

    ASSERT_EQ(mem_map->vmentry[7]->npages,
              1 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[7]->prot,
              NACL_ABI_PROT_READ);

    ASSERT_EQ(mem_map->vmentry[8]->npages,
              3 * NACL_PAGES_PER_MAP);
    ASSERT_EQ(mem_map->vmentry[8]->prot,
              NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE);


    /*
     * Undo effects of previous mmaps
     */
    errcode = NaClSysMunmap(natp, (void *) (uintptr_t) initial_addr,
                            9 * NACL_MAP_PAGESIZE);
    ASSERT_EQ(errcode, 0);
    ASSERT_EQ(mem_map->nvalid, 5);
    CheckLowerMappings(mem_map);
    /*
     * Mappings return to being:
     * 0. --  Zero page
     * 1. rx  Static code segment
     * 2. r   Read-only data segment
     * 3. rw  Writable data segment
     * 4. rw  Stack
     */

    /*
     * Check use of hint.
     */
    addr = NaClSysMmapIntern(nap, (void *) (uintptr_t) initial_addr,
                             NACL_MAP_PAGESIZE,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                             -1, 0);
    ASSERT_LE(addr, 0xffff0000u);
    printf("addr=0x%"NACL_PRIx32"\n", addr);
    ASSERT_LE_MSG(initial_addr, addr, "returned address not at or above hint");
    errcode = NaClSysMunmap(natp, (void *) (uintptr_t) addr, NACL_MAP_PAGESIZE);
    ASSERT_EQ(errcode, 0);

    /* Check handling of zero-sized mappings. */
    addr = NaClSysMmapIntern(nap, 0, 0,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                             -1, 0);
    ASSERT_EQ((int) addr, -NACL_ABI_EINVAL);

    errcode = NaClSysMunmap(natp, (void *) (uintptr_t) initial_addr, 0);
    ASSERT_EQ(errcode, -NACL_ABI_EINVAL);

    /* Check changing the memory protection of neighbouring mmaps */
    addr = NaClSysMmapIntern(nap, 0, NACL_MAP_PAGESIZE,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE,
                             -1, 0);
    printf("addr=0x%"NACL_PRIx32"\n", addr);
    initial_addr = addr;
    addr = NaClSysMmapIntern(nap, (void *) (uintptr_t) (initial_addr +
                             NACL_MAP_PAGESIZE),
                             NACL_MAP_PAGESIZE,
                             NACL_ABI_PROT_READ | NACL_ABI_PROT_WRITE,
                             NACL_ABI_MAP_ANONYMOUS | NACL_ABI_MAP_PRIVATE
                             | NACL_ABI_MAP_FIXED,
                             -1, 0);
    printf("addr=0x%"NACL_PRIx32"\n", addr);
    ASSERT_EQ(addr, initial_addr + NACL_MAP_PAGESIZE);

    errcode = NaClSysMprotectInternal(nap, initial_addr,
                                      2 * NACL_MAP_PAGESIZE,
                                      NACL_ABI_PROT_READ);
    ASSERT_EQ(errcode, 0);

    /* Undo effects of previous mmaps */
    errcode = NaClSysMunmap(natp, (void *) (uintptr_t) initial_addr,
                            2 * NACL_MAP_PAGESIZE);
    ASSERT_EQ(errcode, 0);

    /* Check that we cannot make the read-only data segment writable */
    ent = mem_map->vmentry[2];
    errcode = NaClSysMprotectInternal(nap, (uint32_t) (ent->page_num <<
                                      NACL_PAGESHIFT),
                                      ent->npages * NACL_MAP_PAGESIZE,
                                      NACL_ABI_PROT_WRITE);
    ASSERT_EQ(errcode, -NACL_ABI_EACCES);

#if NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86 && NACL_BUILD_SUBARCH == 64
    CheckForGuardRegion(nap->mem_start - ((size_t) 40 << 30), (size_t) 40 << 30);
    CheckForGuardRegion(nap->mem_start + ((size_t) 4 << 30), (size_t) 40 << 30);
#endif

    NaClAddrSpaceFree(nap);

    printf("PASS\n");
    return 0;
}