Preparing rollback in case things don't work out....

chrome/nacl/sel_main.cc

-// Copyright (c) 2006-2009 The Chromium 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 "build/build_config.h"
-
-#include "native_client/src/include/portability.h"
-
-#if NACL_OSX
-#include <crt_externs.h>
-#endif
-
-EXTERN_C_BEGIN
-#include "native_client/src/shared/platform/nacl_sync.h"
-#include "native_client/src/shared/platform/nacl_sync_checked.h"
-#include "native_client/src/trusted/service_runtime/nacl_globals.h"
-#include "native_client/src/trusted/service_runtime/expiration.h"
-#include "native_client/src/trusted/service_runtime/nacl_app.h"
-#include "native_client/src/trusted/service_runtime/nacl_all_modules.h"
-#include "native_client/src/trusted/service_runtime/sel_ldr.h"
-#include "native_client/src/trusted/platform_qualify/nacl_os_qualify.h"
-EXTERN_C_END
-
-int verbosity = 0;
-
-#ifdef __GNUC__
-
-/*
- * GDB's canonical overlay managment routine.
- * We need its symbol in the symbol table so don't inline it.
- * TODO(dje): add some explanation for the non-GDB person.
- */
-
-static void __attribute__ ((noinline)) _ovly_debug_event (void) {
-  /*
-   * The asm volatile is here as instructed by the GCC docs.
-   * It's not enough to declare a function noinline.
-   * GCC will still look inside the function to see if it's worth calling.
-   */
-  asm volatile ("");
-}
-
-#endif
-
-static void StopForDebuggerInit (const struct NaClApp *state) {
-  /* Put xlate_base in a place where gdb can find it.  */
-  nacl_global_xlate_base = state->xlate_base;
-
-#ifdef __GNUC__
-  _ovly_debug_event ();
-#endif
-}
-
-int SelMain(const int desc, const NaClHandle handle) {
-  char *av[1];
-  int ac = 1;
-
-  char                          **envp;
-  struct NaClApp                state;
-  char                          *nacl_file = 0;
-  int                           main_thread_only = 1;
-  int                           export_addr_to = -2;
-
-  struct NaClApp                *nap;
-
-  NaClErrorCode                 errcode;
-
-  int                           ret_code = 1;
-#if NACL_OSX
-  // Mac dynamic libraries cannot access the environ variable directly.
-  envp = *_NSGetEnviron();
-#else
-  extern char                   **environ;
-  envp = environ;
-#endif
-
-
-  if (NaClHasExpired()) {
-    // TODO(gregoryd): report error to browser?
-    fprintf(stderr, "This version of Native Client has expired.\n");
-    fprintf(stderr, "Please visit: http://code.google.com/p/nativeclient/\n");
-    exit(-1);
-  }
-
-  NaClAllModulesInit();
-
-  /* used to be -P */
-  NaClSrpcFileDescriptor = desc;
-  /* used to be -X */
-  export_addr_to = desc;
-
-  /* to be passed to NaClMain, eventually... */
-  av[0] = const_cast<char*>("NaClMain");
-
-  if (!NaClAppCtor(&state)) {
-    fprintf(stderr, "Error while constructing app state\n");
-    goto done_file_dtor;
-  }
-
-  state.restrict_to_main_thread = main_thread_only;
-
-  nap = &state;
-  errcode = LOAD_OK;
-
-  /* import IMC handle - used to be "-i" */
-  NaClAddImcHandle(nap, handle, desc);
-
-  /*
-   * in order to report load error to the browser plugin through the
-   * secure command channel, we do not immediate jump to cleanup code
-   * on error.  rather, we continue processing (assuming earlier
-   * errors do not make it inappropriate) until the secure command
-   * channel is set up, and then bail out.
-   */
-
-  /*
-   * Ensure this operating system platform is supported.
-   */
-  if (!NaClOsIsSupported()) {
-    errcode = LOAD_UNSUPPORTED_OS_PLATFORM;
-    nap->module_load_status = errcode;
-    fprintf(stderr, "Error while loading \"%s\": %s\n",
-            nacl_file,
-            NaClErrorString(errcode));
-  }
-
-  /* Give debuggers a well known point at which xlate_base is known.  */
-  StopForDebuggerInit(&state);
-
-  /*
-   * If export_addr_to is set to a non-negative integer, we create a
-   * bound socket and socket address pair and bind the former to
-   * descriptor 3 and the latter to descriptor 4.  The socket address
-   * is written out to the export_addr_to descriptor.
-   *
-   * The service runtime also accepts a connection on the bound socket
-   * and spawns a secure command channel thread to service it.
-   *
-   * If export_addr_to is -1, we only create the bound socket and
-   * socket address pair, and we do not export to an IMC socket.  This
-   * use case is typically only used in testing, where we only "dump"
-   * the socket address to stdout or similar channel.
-   */
-  if (-2 < export_addr_to) {
-    NaClCreateServiceSocket(nap);
-    if (0 <= export_addr_to) {
-      NaClSendServiceAddressTo(nap, export_addr_to);
-      /*
-       * NB: spawns a thread that uses the command channel.  we do
-       * this after NaClAppLoadFile so that NaClApp object is more
-       * fully populated.  Hereafter any changes to nap should be done
-       * while holding locks.
-       */
-      NaClSecureCommandChannel(nap);
-    }
-  }
-
-  NaClXMutexLock(&nap->mu);
-  nap->module_load_status = LOAD_OK;
-  NaClXCondVarBroadcast(&nap->cv);
-  NaClXMutexUnlock(&nap->mu);
-
-  if (NULL != nap->secure_channel) {
-    /*
-     * wait for start_module RPC call on secure channel thread.
-     */
-    NaClWaitForModuleStartStatusCall(nap);
-  }
-
-  /*
-   * error reporting done; can quit now if there was an error earlier.
-   */
-  if (LOAD_OK != errcode) {
-    goto done;
-  }
-
-  /*
-   * only nap->ehdrs.e_entry is usable, no symbol table is
-   * available.
-   */
-  if (!NaClCreateMainThread(nap,
-                            ac,
-                            av,
-                            envp)) {
-    fprintf(stderr, "creating main thread failed\n");
-    goto done;
-  }
-
-  ret_code = NaClWaitForMainThreadToExit(nap);
-
-  /*
-   * exit_group or equiv kills any still running threads while module
-   * addr space is still valid.  otherwise we'd have to kill threads
-   * before we clean up the address space.
-   */
-  return ret_code;
-
- done:
-  fflush(stdout);
-
-  NaClAppDtor(&state);
-
- done_file_dtor:
-  fflush(stdout);
-
-  NaClAllModulesFini();
-
-  return ret_code;
-}
-