Non-SFI mode: Use dummy PID for NaCl's IPC channel on Linux platform.

components/nacl/loader/nacl_helper_linux.cc

 // Copyright 2013 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.
 
 // A mini-zygote specifically for Native Client.
 
 #include "components/nacl/loader/nacl_helper_linux.h"
 
 // Exclude most of code in this file for nacl_helper_nonsfi temporarily.
 // TODO(hidehiko): Enable this code path as dependencies become ready.
@@ skipping 30 matching lines @@
 #include "base/rand_util.h"
 #include "components/nacl/common/nacl_switches.h"
 #include "components/nacl/loader/nacl_listener.h"
 #include "components/nacl/loader/nonsfi/irt_exception_handling.h"
 #include "components/nacl/loader/nonsfi/nonsfi_listener.h"
 #include "components/nacl/loader/sandbox_linux/nacl_sandbox_linux.h"
 #include "content/public/common/child_process_sandbox_support_linux.h"
 #include "content/public/common/content_descriptors.h"
 #include "content/public/common/zygote_fork_delegate_linux.h"
 #include "crypto/nss_util.h"
+#include "ipc/ipc_channel.h"
 #include "ipc/ipc_descriptors.h"
 #include "ipc/ipc_switches.h"
 #include "sandbox/linux/services/libc_urandom_override.h"
 
 namespace {
 
 struct NaClLoaderSystemInfo {
   size_t prereserved_sandbox_size;
   long number_of_cores;
 };
@@ skipping 336 matching lines @@
 // stripped by the linker.
 __attribute__((used))
 __attribute__((visibility("default")))
 const char* __asan_default_options() {
   return kAsanDefaultOptionsNaCl;
 }
 #endif
 #endif  // !defined(__native_client_nonsfi__)
 
 int main(int argc, char* argv[]) {
   // Now do nothing in main for nacl_helper_nonsfi.

[Mark Seaborn, 2014/12/03 01:54:00]

Can you rebase this change, so that I can see what the current context is?

[hidehiko, 2014/12/03 17:03:19]

Done.

 #if !defined(__native_client_nonsfi__)
   CommandLine::Init(argc, argv);
+  IPC::Channel::SetGlobalPid(-1);  // Set dummy PID for IPC.

[mdempsky, 2014/11/07 03:05:34]

Is this the right place to put this call?  It looks like this for !nonsfi,
whereas in ipc_channel.h it seems like SetGlobalPid() is only available for
OS_LINUX and NONSFI.  I would think this wouldn't compile under SFI.

[hidehiko, 2014/11/07 05:43:21]

Yes, this is the right place.
This is not only for nonsfi but also for sfi. Note that nacl_helper for sfi mode
is build by host toolchain (i.e. under OS_LINUX rather than OS_NACL). We won't
compile this file to SFI nexe binary.

   base::AtExitManager exit_manager;
   base::RandUint64();  // acquire /dev/urandom fd before sandbox is raised
   // Allows NSS to fopen() /dev/urandom.
   sandbox::InitLibcUrandomOverrides();
 #if defined(USE_NSS)
   // Configure NSS for use inside the NaCl process.
   // The fork check has not caused problems for NaCl, but this appears to be
   // best practice (see other places LoadNSSLibraries is called.)
   crypto::DisableNSSForkCheck();
   // Without this line on Linux, HMAC::Init will instantiate a singleton that
@@ skipping 34 matching lines @@
   while (true) {
     bool request_handled = HandleZygoteRequest(
         kNaClZygoteDescriptor, system_info, nacl_sandbox.get());
     // Do not turn this into a CHECK() without thinking about robustness
     // against malicious IPC requests.
     DCHECK(request_handled);
   }
   NOTREACHED();
 #endif  // !defined(__native_client_nonsfi__)
 }