1                 : /*
       2                 :  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
       3                 :  * Use of this source code is governed by a BSD-style license that can be
       4                 :  * found in the LICENSE file.
       5                 :  */
       6                 : 
       7                 : #include <stdlib.h>
       8                 : #include <stdio.h>
       9                 : 
      10                 : #include "native_client/src/include/portability.h"
      11                 : #include "native_client/src/shared/platform/nacl_exit.h"
      12                 : #include "native_client/src/trusted/service_runtime/nacl_signal.h"
      13                 : 
      14                 : 
      15               0 : void NaClAbort(void) {
      16                 :   /*
      17                 :    * We crash the process with a HLT instruction so that the Breakpad
      18                 :    * crash reporter will be invoked when we are running inside Chrome.
      19                 :    *
      20                 :    * This has the disadvantage that an untrusted-code crash will not
      21                 :    * be distinguishable from a trusted-code NaClAbort() based on the
      22                 :    * process's exit status alone
      23                 :    *
      24                 :    * While we could use the INT3 breakpoint instruction to exit (via
      25                 :    * __debugbreak()), that does not work if NaCl's debug exception
      26                 :    * handler is attached, because that always resumes breakpoints (see
      27                 :    * http://code.google.com/p/nativeclient/issues/detail?id=2772).
      28                 :    */
      29               0 :   while (1) {
      30               0 :     __halt();
      31               0 :   }
      32               0 : }
      33                 : 
      34               0 : void NaClExit(int err_code) {
      35                 : #ifdef COVERAGE
      36                 :   /* Give coverage runs a chance to flush coverage data */
      37               0 :   exit(err_code);
      38                 : #else
      39                 :   /*
      40                 :    * We want to exit without running any finalization code, because
      41                 :    * that could cause currently-running threads to crash.
      42                 :    *
      43                 :    * We avoid using exit() because it calls atexit() handlers.  We
      44                 :    * avoid using _exit() because it is documented as doing some
      45                 :    * internal C library shutdown.
      46                 :    *
      47                 :    * We avoid using TerminateProcess() because it terminates threads
      48                 :    * in a non-deterministic order.  On Windows, the exit status of a
      49                 :    * process is taken to be the exit status of the last thread that
      50                 :    * exited.  Using TerminateProcess() makes the exit status of the
      51                 :    * process unreliable; this used to cause many tests to be flaky.
      52                 :    * See https://code.google.com/p/nativeclient/issues/detail?id=2870
      53                 :    *
      54                 :    * ExitProcess() has the following properties:
      55                 :    *
      56                 :    *  - It first terminates all threads except the calling thread.
      57                 :    *    This prevents these threads from messing up the process exit
      58                 :    *    status.
      59                 :    *
      60                 :    *  - It calls loaded DLLs' finalization routines.  This is not
      61                 :    *    ideal, but it is OK because NaClExit() should only be used for
      62                 :    *    graceful exits (when no internal errors have been detected),
      63                 :    *    and because there will be no other threads at this point.
      64                 :    */
      65                 :   ExitProcess(err_code);
      66                 : 
      67                 :   /* Just in case. */
      68                 :   NaClAbort();
      69                 : #endif
      70                 : }