[macOS] Block runningboard access in the Network Process sandbox again

https://bugs.webkit.org/show_bug.cgi?id=259274

Reviewed by Per Arne Vollan.

Block runningboard access in the Network Process sandbox again on macOS and
address Bug 259229 by always holding a background assertion on the network
process (so that it never suspends).

* Source/WebKit/NetworkProcess/NetworkProcess.cpp:
(WebKit::NetworkProcess::setIsHoldingLockedFiles):
* Source/WebKit/NetworkProcess/mac/com.apple.WebKit.NetworkProcess.sb.in:
* Source/WebKit/UIProcess/Network/NetworkProcessProxy.cpp:
(WebKit::NetworkProcessProxy::NetworkProcessProxy):
* Source/WebKit/UIProcess/Network/NetworkProcessProxy.h:

Canonical link: https://commits.webkit.org/266101@main

Source/WebKit/NetworkProcess/NetworkProcess.cpp

@@ -2974,6 +2974,10 @@ void NetworkProcess::requestBackgroundFetchPermission(PAL::SessionID sessionID,
 #if USE(RUNNINGBOARD)
 void NetworkProcess::setIsHoldingLockedFiles(bool isHoldingLockedFiles)
 {
+#if PLATFORM(MAC)
+    // The sandbox doesn't allow the network process to talk to runningboardd on macOS.
+    UNUSED_PARAM(isHoldingLockedFiles);
+#else
     if (!isHoldingLockedFiles) {
         m_holdingLockedFileAssertion = nullptr;
         return;
@@ -2985,6 +2989,7 @@ void NetworkProcess::setIsHoldingLockedFiles(bool isHoldingLockedFiles)
     // We synchronously take a process assertion when beginning a SQLite transaction so that we don't get suspended
     // while holding a locked file. We would get killed if suspended while holding locked files.
     m_holdingLockedFileAssertion = ProcessAssertion::create(getCurrentProcessID(), "Network Process is holding locked files"_s, ProcessAssertionType::FinishTaskInterruptable, ProcessAssertion::Mode::Sync);
+#endif
 }
 #endif
 

Source/WebKit/NetworkProcess/mac/com.apple.WebKit.NetworkProcess.sb.in

@@ -836,8 +836,3 @@
     (global-name "com.apple.WebPrivacy.Service"))
 
 #endif
-
-#if USE(RUNNINGBOARD)
-(allow mach-lookup
-    (global-name "com.apple.runningboard"))
-#endif

Source/WebKit/UIProcess/Network/NetworkProcessProxy.cpp

@@ -258,6 +258,9 @@ NetworkProcessProxy::NetworkProcessProxy()
     , m_customProtocolManagerClient(makeUniqueRef<API::CustomProtocolManagerClient>())
 #endif
     , m_throttler(*this, WebProcessPool::anyProcessPoolNeedsUIBackgroundAssertion())
+#if PLATFORM(MAC)
+    , m_backgroundActivityToPreventSuspension(m_throttler.backgroundActivity("Prevent suspension"_s))
+#endif
 {
     RELEASE_LOG(Process, "%p - NetworkProcessProxy::NetworkProcessProxy", this);
 

Source/WebKit/UIProcess/Network/NetworkProcessProxy.h

@@ -455,6 +455,14 @@ class NetworkProcessProxy final : public AuxiliaryProcessProxy, private ProcessT
 
     WeakHashSet<WebsiteDataStore> m_websiteDataStores;
     HashMap<DataTaskIdentifier, Ref<API::DataTask>> m_dataTasks;
+#if PLATFORM(MAC)
+    // On macOS, we prevent suspension of the NetworkProcess to avoid kills when holding
+    // locked database files. The WebSQLiteDatabaseTracker is not functional on macOS
+    // because the network process is not allowed to talk to talk to runningboardd due
+    // to sandboxing. See rdar://112406083 & rdar://112086186 for potential long-term
+    // fixes.
+    UniqueRef<ProcessThrottlerActivity> m_backgroundActivityToPreventSuspension;
+#endif
 
 #if PLATFORM(IOS_FAMILY)
     RetainPtr<id> m_backgroundObserver;