third_party/android_crazy_linker/src/tests/test_shared_relro.cpp

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // A crazy linker test to:
   6 // - Load a library (libfoo.so) with the linker.
   7 // - Find the address of the "Foo" function in it.
   8 // - Call the function.
   9 // - Close the library.
  10
  11 #include <errno.h>
  12 #include <stdarg.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <sys/socket.h>
  16 #include <sys/uio.h>
  17 #include <sys/wait.h>
  18 #include <unistd.h>
  19
  20 #include <crazy_linker.h>
  21
  22 #include "test_util.h"
  23
  24 typedef void (*FunctionPtr)();
  25
  26 int main() {
  27
  28   if (!crazy_system_can_share_relro()) {
  29     fprintf(stderr, "WARNING: Test ignored due to broken kernel!!\n");
  30     return 0;
  31   }
  32
  33   crazy_context_t* context = crazy_context_create();
  34
  35   RelroLibrary foo;
  36
  37   // Load at fixed address to simplify testing.
  38   crazy_context_set_load_address(context, 0x20000000);
  39   foo.Init("libfoo_with_relro.so", context);
  40
  41   printf("Library loaded\n");
  42
  43   int pipes[2];
  44   if (socketpair(AF_UNIX, SOCK_STREAM, 0, pipes) < 0)
  45     Panic("Could not create socket pair: %s", strerror(errno));
  46
  47   pid_t child = fork();
  48   if (child < 0)
  49     Panic("Could not fork test program!");
  50
  51   if (child == 0) {
  52     // In the child.
  53     printf("Child waiting for foo relro fd\n");
  54
  55     foo.ReceiveRelroInfo(pipes[0]);
  56     foo.UseSharedRelro(context);
  57
  58     printf("RELRO used in child process\n");
  59
  60     CheckRelroMaps(1);
  61
  62     FunctionPtr foo_func;
  63     if (!crazy_library_find_symbol(
  64              foo.library, "Foo", reinterpret_cast<void**>(&foo_func)))
  65       Panic("Could not find 'Foo' in library");
  66
  67     printf("Calling Foo()\n");
  68     (*foo_func)();
  69
  70     printf("Foo called, exiting\n");
  71
  72     exit(0);
  73
  74   } else {
  75     // In the parent.
  76
  77     printf("Parent enabling foo RELRO sharing\n");
  78
  79     foo.EnableSharedRelro(context);
  80     foo.SendRelroInfo(pipes[1]);
  81
  82     printf("RELRO enabled and sent to child\n");
  83
  84     CheckRelroMaps(1);
  85
  86     printf("Parent waiting for child\n");
  87
  88     // Wait for child to complete.
  89     int status;
  90     waitpid(child, &status, 0);
  91
  92     if (WIFSIGNALED(status))
  93       Panic("Child terminated by signal!!\n");
  94     else if (WIFEXITED(status)) {
  95       int child_status = WEXITSTATUS(status);
  96       if (child_status != 0)
  97         Panic("Child terminated with status=%d\n", child_status);
  98     } else
  99       Panic("Child exited for unknown reason!!\n");
 100   }
 101
 102   crazy_context_destroy(context);
 103   return 0;
 104 }