Make sanitizer signal handlers work again.

services/service_manager/embedder/main.cc

 // Copyright 2017 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 "services/service_manager/embedder/main.h"
 
 #include "base/allocator/features.h"
 #include "base/at_exit.h"
 #include "base/base_switches.h"
 #include "base/command_line.h"
@@ skipping 90 matching lines @@
 
   MainDelegate* const main_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceProcessLauncherDelegateImpl);
 };
 
 #if defined(OS_POSIX) && !defined(OS_ANDROID)
 
 // Setup signal-handling state: resanitize most signals, ignore SIGPIPE.
 void SetupSignalHandlers() {
+#if !defined(ADDRESS_SANITIZER) && !defined(LEAK_SANITIZER) &&  \

[jam, 2017/04/28 00:24:50]

can we use the same switch as in content? i..e move it from content/ to
services/service_manager/switches.h, and then have this code and content use it?

that way, knowledge about what breaks asan is on asan bot (through command line
flag) instead of here which is quite removed from it

[Oliver Chang, 2017/04/28 17:05:06]

Done. I put it in service_manager/embedder/switches.h instead since otherwise
there's a dependency from service_manager/embedder to service_manager/ and GN
complains. I hope this is fine?

I kept the sanitizer #ifdef checks in so that in a non-sanitizer build there's
no unintended side effects from disabling in process stack traces.

[jam, 2017/05/01 15:37:24]

Even content doesn't have these checks, so I don't think we have anything to
worry about. Let's remove them, since keeping them there means that this code
has knowledge about what breaks *san which is what the switch is trying to
avoid.

[Oliver Chang, 2017/05/01 16:05:14]

Sure, removed.

+    !defined(MEMORY_SANITIZER) && !defined(THREAD_SANITIZER) && \
+    !defined(UNDEFINED_SANITIZER)
   // Sanitise our signal handling state. Signals that were ignored by our
   // parent will also be ignored by us. We also inherit our parent's sigmask.
   sigset_t empty_signal_set;
   CHECK_EQ(0, sigemptyset(&empty_signal_set));
   CHECK_EQ(0, sigprocmask(SIG_SETMASK, &empty_signal_set, NULL));
 
   struct sigaction sigact;
   memset(&sigact, 0, sizeof(sigact));
   sigact.sa_handler = SIG_DFL;
   static const int signals_to_reset[] = {
       SIGHUP,  SIGINT,  SIGQUIT, SIGILL, SIGABRT, SIGFPE, SIGSEGV,
       SIGALRM, SIGTERM, SIGCHLD, SIGBUS, SIGTRAP};  // SIGPIPE is set below.
   for (unsigned i = 0; i < arraysize(signals_to_reset); i++) {
     CHECK_EQ(0, sigaction(signals_to_reset[i], &sigact, NULL));
   }
 
   // Always ignore SIGPIPE.  We check the return value of write().
   CHECK_NE(SIG_ERR, signal(SIGPIPE, SIG_IGN));
+#endif
 }
 
 void PopulateFDsFromCommandLine() {
   const std::string& shared_file_param =
       base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kSharedFiles);
   if (shared_file_param.empty())
     return;
 
   base::Optional<std::map<int, std::string>> shared_file_descriptors =
@@ skipping 327 matching lines @@
   autorelease_pool.reset();
 #endif
 
   if (process_type == ProcessType::kEmbedder)
     delegate->ShutDownEmbedderProcess();
 
   return exit_code;
 }
 
 }  // namespace service_manager