kern: allow ktrace map capability when ktrace is disabled

libraries/libmesosphere/source/kern_k_capabilities.cpp

@@ -184,6 +184,11 @@ namespace ams::kern {
                 case RegionType::NoMapping:
                     break;
                 case RegionType::KernelTraceBuffer:
+                    /* NOTE: This does not match official, but is used to make pre-processing hbl capabilities in userland unnecessary. */
+                    /* If ktrace isn't enabled, allow ktrace to succeed without mapping anything. */
+                    if constexpr (!ams::kern::IsKTraceEnabled) {
+                        break;
+                    }
                 case RegionType::OnMemoryBootImage:
                 case RegionType::DTB:
                     R_TRY(f(MemoryRegions[static_cast<u32>(type)], perm));

stratosphere/loader/source/ldr_capabilities.cpp

@@ -418,15 +418,7 @@ namespace ams::ldr {
         for (size_t i = 0; i < count; ++i) {
             const auto cap = kac[i];
             switch (GetCapabilityId(cap)) {
-                case CapabilityId::MapRegion:
+                /* NOTE: Currently, there is no pre-processing necessary. */
-                    {
-                        /* MapRegion was added in 8.0.0+, and is only allowed under kernels which have the relevant mappings. */
-                        /* However, we allow it under all firmwares on mesosphere, to facilitate KTrace usage by hbl. */
-                        if (!svc::IsKTraceEnabled()) {
-                            kac[i] = EmptyCapability;
-                        }
-                    }
-                    break;
                 default:
                     break;
             }