Adding untrusted crash dump / stack trace tests.

tests/exception_test/exception_test.c

 /*
  * 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.
  */
 
 #include <assert.h>
 #include <errno.h>
 #include <setjmp.h>
 #include <stdint.h>
@@ skipping 284 matching lines @@
 /*
  * TODO(mseaborn): %ebp is preserved when entering the exception
  * handler because its value is needed for doing stack backtraces, but
  * it would be better to save its value in the exception frame.
  */
 
 uint32_t saved_ebp;
 
 void ebp_exception_handler_wrapper(int prog_ctr, int stack_ptr);
 asm(".pushsection .text, \"ax\", @progbits\n"
+    ".p2align NACLENTRYALIGN\n"

[Mark Seaborn, 2012/02/13 19:04:08]

If you could split this out into a separate changeset, it would help.  You don't
have to, but it would help make the review process go quicker since there would
be fewer things for me to keep track of.

[bradn, 2012/02/13 23:42:03]

Done.

     "ebp_exception_handler_wrapper:\n"
     "mov %ebp, saved_ebp\n"
     "jmp ebp_exception_handler\n"
     ".popsection\n");
 
 void ebp_exception_handler() {
   assert(saved_ebp == 0x12345678);
   /* Return from exception handler. */
   int rc = NACL_SYSCALL(exception_clear_flag)();
   assert(rc == 0);
@@ skipping 41 matching lines @@
   test_unsetting_x86_direction_flag();
 #endif
 
 #if defined(__i386__)
   test_preserving_ebp();
 #endif
 
   fprintf(stderr, "** intended_exit_status=0\n");
   return 0;
 }