kernel/svc: Sanitize core number and thread priorities in CreateThread()

Now that we handle the kernel capability descriptors we can correct
CreateThread to properly check against the core and priority masks
like the actual kernel does.

src/core/hle/kernel/svc.cpp

@@ -1219,12 +1219,6 @@ static ResultCode CreateThread(Handle* out_handle, VAddr entry_point, u64 arg, V
               "threadpriority=0x{:08X}, processorid=0x{:08X} : created handle=0x{:08X}",
               entry_point, arg, stack_top, priority, processor_id, *out_handle);
 
-    if (priority > THREADPRIO_LOWEST) {
-        LOG_ERROR(Kernel_SVC, "An invalid priority was specified, expected {} but got {}",
-                  THREADPRIO_LOWEST, priority);
-        return ERR_INVALID_THREAD_PRIORITY;
-    }
-
     auto* const current_process = Core::CurrentProcess();
 
     if (processor_id == THREADPROCESSORID_IDEAL) {
@@ -1238,6 +1232,23 @@ static ResultCode CreateThread(Handle* out_handle, VAddr entry_point, u64 arg, V
         return ERR_INVALID_PROCESSOR_ID;
     }
 
+    const u64 core_mask = current_process->GetCoreMask();
+    if ((core_mask | (1ULL << processor_id)) != core_mask) {
+        LOG_ERROR(Kernel_SVC, "Invalid thread core specified ({})", processor_id);
+        return ERR_INVALID_PROCESSOR_ID;
+    }
+
+    if (priority > THREADPRIO_LOWEST) {
+        LOG_ERROR(Kernel_SVC, "An invalid priority was specified, expected {} but got {}",
+                  THREADPRIO_LOWEST, priority);
+        return ERR_INVALID_THREAD_PRIORITY;
+    }
+
+    if (((1ULL << priority) & current_process->GetPriorityMask()) == 0) {
+        LOG_ERROR(Kernel_SVC, "Invalid thread priority specified ({})", priority);
+        return ERR_INVALID_THREAD_PRIORITY;
+    }
+
     const std::string name = fmt::format("thread-{:X}", entry_point);
     auto& kernel = Core::System::GetInstance().Kernel();
     CASCADE_RESULT(SharedPtr<Thread> thread,