Bug 1741152 - Add diagnostic warnings to process launch codepaths, r=ipc-reviewers,mccr8

Differential Revision: https://phabricator.services.mozilla.com/D131419

dom/ipc/ContentParent.cpp

@@ -1081,7 +1081,7 @@ ContentParent::GetNewOrUsedLaunchingBrowserProcess(
              PromiseFlatCString(aRemoteType).get()));
 
     contentParent = new ContentParent(aRemoteType);
-    if (!contentParent->BeginSubprocessLaunch(aPriority)) {
+    if (NS_WARN_IF(!contentParent->BeginSubprocessLaunch(aPriority))) {
       // Launch aborted because of shutdown. Bailout.
       contentParent->LaunchSubprocessReject();
       return nullptr;
@@ -2503,7 +2503,8 @@ bool ContentParent::BeginSubprocessLaunch(ProcessPriority aPriority) {
   AUTO_PROFILER_LABEL("ContentParent::LaunchSubprocess", OTHER);
 
   if (!ContentProcessManager::GetSingleton()) {
-    // Shutdown has begun, we shouldn't spawn any more child processes.
+    NS_WARNING(
+        "Shutdown has begun, we shouldn't spawn any more child processes");
     return false;
   }
 
@@ -2519,6 +2520,7 @@ bool ContentParent::BeginSubprocessLaunch(ProcessPriority aPriority) {
   // `LaunchSubprocessReject`/`LaunchSubprocessResolve`.
   mPrefSerializer = MakeUnique<mozilla::ipc::SharedPreferenceSerializer>();
   if (!mPrefSerializer->SerializeToSharedMemory()) {
+    NS_WARNING("SharedPreferenceSerializer::SerializeToSharedMemory failed");
     MarkAsDead();
     return false;
   }
@@ -2628,6 +2630,7 @@ bool ContentParent::LaunchSubprocessResolve(bool aIsSync,
   // marked as DEAD, fail the process launch, and immediately begin tearing down
   // the content process.
   if (IsDead()) {
+    NS_WARNING("immediately shutting-down already-dead process");
     ShutDownProcess(SEND_SHUTDOWN_MESSAGE);
     return false;
   }

ipc/chromium/src/base/process_util_linux.cc

@@ -244,6 +244,7 @@ bool LaunchApp(const std::vector<std::string>& argv,
   EnvironmentArray envp = BuildEnvironmentArray(options.env_map);
   mozilla::ipc::FileDescriptorShuffle shuffle;
   if (!shuffle.Init(options.fds_to_remap)) {
+    DLOG(WARNING) << "FileDescriptorShuffle::Init failed";
     return false;
   }
 
@@ -269,7 +270,10 @@ bool LaunchApp(const std::vector<std::string>& argv,
   pid_t pid = fork();
 #endif
 
-  if (pid < 0) return false;
+  if (pid < 0) {
+    DLOG(WARNING) << "fork() failed: " << strerror(errno);
+    return false;
+  }
 
   if (pid == 0) {
     // In the child:

ipc/chromium/src/base/process_util_mac.mm

@@ -40,6 +40,7 @@ bool LaunchApp(const std::vector<std::string>& argv, const LaunchOptions& option
 
   posix_spawn_file_actions_t file_actions;
   if (posix_spawn_file_actions_init(&file_actions) != 0) {
+    DLOG(WARNING) << "posix_spawn_file_actions_init failed";
     return false;
   }
   auto file_actions_guard =
@@ -48,6 +49,7 @@ bool LaunchApp(const std::vector<std::string>& argv, const LaunchOptions& option
   // Turn fds_to_remap array into a set of dup2 calls.
   mozilla::ipc::FileDescriptorShuffle shuffle;
   if (!shuffle.Init(options.fds_to_remap)) {
+    DLOG(WARNING) << "FileDescriptorShuffle::Init failed";
     return false;
   }
   for (const auto& fd_map : shuffle.Dup2Sequence()) {
@@ -55,6 +57,7 @@ bool LaunchApp(const std::vector<std::string>& argv, const LaunchOptions& option
     int dest_fd = fd_map.second;
 
     if (posix_spawn_file_actions_adddup2(&file_actions, src_fd, dest_fd) != 0) {
+      DLOG(WARNING) << "posix_spawn_file_actions_adddup2 failed";
       return false;
     }
   }
@@ -62,6 +65,7 @@ bool LaunchApp(const std::vector<std::string>& argv, const LaunchOptions& option
   // Initialize spawn attributes.
   posix_spawnattr_t spawnattr;
   if (posix_spawnattr_init(&spawnattr) != 0) {
+    DLOG(WARNING) << "posix_spawnattr_init failed";
     return false;
   }
   auto spawnattr_guard =
@@ -75,6 +79,7 @@ bool LaunchApp(const std::vector<std::string>& argv, const LaunchOptions& option
     int rv;
     rv = posix_spawnattr_setbinpref_np(&spawnattr, count, &cpu_pref, &ocount);
     if ((rv != 0) || (ocount != count)) {
+      DLOG(WARNING) << "posix_spawnattr_setbinpref_np failed";
       return false;
     }
   }
@@ -84,12 +89,14 @@ bool LaunchApp(const std::vector<std::string>& argv, const LaunchOptions& option
   // that aren't named in `file_actions`.  (This is an Apple-specific
   // extension to posix_spawn.)
   if (posix_spawnattr_setflags(&spawnattr, POSIX_SPAWN_CLOEXEC_DEFAULT) != 0) {
+    DLOG(WARNING) << "posix_spawnattr_setflags failed";
     return false;
   }
 
   // Exempt std{in,out,err} from being closed by POSIX_SPAWN_CLOEXEC_DEFAULT.
   for (int fd = 0; fd <= STDERR_FILENO; ++fd) {
     if (posix_spawn_file_actions_addinherit_np(&file_actions, fd) != 0) {
+      DLOG(WARNING) << "posix_spawn_file_actions_addinherit_np failed";
       return false;
     }
   }
@@ -100,6 +107,7 @@ bool LaunchApp(const std::vector<std::string>& argv, const LaunchOptions& option
 
   bool process_handle_valid = pid > 0;
   if (!spawn_succeeded || !process_handle_valid) {
+    DLOG(WARNING) << "posix_spawnp failed";
     retval = false;
   } else {
     gProcessLog.print("==> process %d launched child process %d\n", GetCurrentProcId(), pid);

ipc/chromium/src/base/process_util_win.cc

@@ -367,7 +367,10 @@ bool LaunchApp(const std::wstring& cmdline, const LaunchOptions& options,
       NULL, const_cast<wchar_t*>(cmdline.c_str()), NULL, NULL, bInheritHandles,
       dwCreationFlags, new_env_ptr, NULL, &startup_info, &process_info);
   if (lpAttributeList) FreeThreadAttributeList(lpAttributeList);
-  if (!createdOK) return false;
+  if (!createdOK) {
+    DLOG(WARNING) << "CreateProcess Failed: " << GetLastError();
+    return false;
+  }
 
   gProcessLog.print("==> process %d launched child process %d (%S)\n",
                     GetCurrentProcId(), process_info.dwProcessId,

ipc/glue/GeckoChildProcessHost.cpp

@@ -279,7 +279,7 @@ class PosixProcessLauncher : public BaseProcessLauncher {
     int origSrcFd;
     aChannel->GetClientFileDescriptorMapping(&origSrcFd, &mChannelDstFd);
     mChannelSrcFd.reset(dup(origSrcFd));
-    if (!mChannelSrcFd) {
+    if (NS_WARN_IF(!mChannelSrcFd)) {
       return false;
     }
     aChannel->CloseClientFileDescriptor();
@@ -1206,8 +1206,8 @@ bool PosixProcessLauncher::DoSetup() {
   if (!CrashReporter::IsDummy()) {
 #  if defined(OS_LINUX) || defined(OS_BSD) || defined(OS_SOLARIS)
     int childCrashFd, childCrashRemapFd;
-    if (!CrashReporter::CreateNotificationPipeForChild(&childCrashFd,
-                                                       &childCrashRemapFd)) {
+    if (NS_WARN_IF(!CrashReporter::CreateNotificationPipeForChild(
+            &childCrashFd, &childCrashRemapFd))) {
       return false;
     }
 
@@ -1431,7 +1431,8 @@ bool WindowsProcessLauncher::DoSetup() {
         // so use sandbox level USER_RESTRICTED instead of USER_LOCKDOWN.
         auto level =
             isWidevine ? SandboxBroker::Restricted : SandboxBroker::LockDown;
-        if (!mResults.mSandboxBroker->SetSecurityLevelForGMPlugin(level)) {
+        if (NS_WARN_IF(
+                !mResults.mSandboxBroker->SetSecurityLevelForGMPlugin(level))) {
           return false;
         }
         mUseSandbox = true;
@@ -1454,7 +1455,8 @@ bool WindowsProcessLauncher::DoSetup() {
       break;
     case GeckoProcessType_RDD:
       if (!PR_GetEnv("MOZ_DISABLE_RDD_SANDBOX")) {
-        if (!mResults.mSandboxBroker->SetSecurityLevelForRDDProcess()) {
+        if (NS_WARN_IF(
+                !mResults.mSandboxBroker->SetSecurityLevelForRDDProcess())) {
           return false;
         }
         mUseSandbox = true;
@@ -1462,7 +1464,8 @@ bool WindowsProcessLauncher::DoSetup() {
       break;
     case GeckoProcessType_Socket:
       if (!PR_GetEnv("MOZ_DISABLE_SOCKET_PROCESS_SANDBOX")) {
-        if (!mResults.mSandboxBroker->SetSecurityLevelForSocketProcess()) {
+        if (NS_WARN_IF(
+                !mResults.mSandboxBroker->SetSecurityLevelForSocketProcess())) {
           return false;
         }
         mUseSandbox = true;
@@ -1690,7 +1693,7 @@ RefPtr<ProcessHandlePromise> AndroidProcessLauncher::LaunchAndroidService(
 #if defined(XP_MACOSX) && defined(MOZ_SANDBOX)
 bool GeckoChildProcessHost::AppendMacSandboxParams(StringVector& aArgs) {
   MacSandboxInfo info;
-  if (!FillMacSandboxInfo(info)) {
+  if (NS_WARN_IF(!FillMacSandboxInfo(info))) {
     return false;
   }
   info.AppendAsParams(aArgs);
@@ -1779,7 +1782,7 @@ RefPtr<ProcessLaunchPromise> BaseProcessLauncher::Launch(
   // great.
   bool failed = false;
   aHost->InitializeChannel([&](IPC::Channel* channel) {
-    if (!channel || !SetChannel(channel)) {
+    if (NS_WARN_IF(!channel || !SetChannel(channel))) {
       failed = true;
     }
   });