kern_start: Resolve iPad patch regression

Closes acidanthera/bugtracker#2166

Author: khronokernel

Changelog.md

@@ -2,6 +2,8 @@ FeatureUnlock Changelog
 ======================
 ### v1.1.1
 - Resolved Macmini8,1 patch regression from 1.1.0
+- Resolved iPad Sidecar patch regression from 1.1.0
+  - Applicable if host model did not require Sidecar patch
 
 ### v1.1.0
 - Refactored model patch set detection

FeatureUnlock/kern_dyld_patch.hpp

@@ -435,11 +435,20 @@ static const uint8_t kNightShiftPatched[] = {
 #pragma mark - Verify Patch Size
 
 // Patching the dyld requires that both the find and replace are of same length
+static_assert(sizeof(kSideCarAirPlayiMacOriginal) == sizeof(kSideCarAirPlayiMacPatched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayiMacAlternative2012Original) == sizeof(kSideCarAirPlayiMacAlternative2012Patched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayiMacAlternative2013Original) == sizeof(kSideCarAirPlayiMacAlternative2013Patched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayiMacAlternative2014Original) == sizeof(kSideCarAirPlayiMacAlternative2014Patched), "patch size invalid");
 static_assert(sizeof(kSideCarAirPlayMacBookOriginal) == sizeof(kSideCarAirPlayMacBookPatched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayMacBookMacBookAir2012Original) == sizeof(kSideCarAirPlayMacBooMacBookAir2012Patched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayMacBookAir2013_2015Original) == sizeof(kSideCarAirPlayMacBookAir2013_2015Patched), "patch size invalid");
 static_assert(sizeof(kSideCarAirPlayMacBookProOriginal) == sizeof(kSideCarAirPlayMacBookProPatched), "patch size invalid");
-static_assert(sizeof(kSideCarAirPlayiMacOriginal) == sizeof(kSideCarAirPlayiMacPatched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayMacBookPro2012Original) == sizeof(kSideCarAirPlayMacBookPro2012Patched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayMacBookPro2013_2015Original) == sizeof(kSideCarAirPlayMacBookPro2013_2015Patched), "patch size invalid");
 static_assert(sizeof(kSideCarAirPlayStandaloneDesktopOriginal) == sizeof(kSideCarAirPlayStandaloneDesktopPatched), "patch size invalid");
-static_assert(sizeof(kMacModelAirplayExtendedOriginal) == sizeof(kMacModelAirplayExtendedPatched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayMacProOriginal) == sizeof(kSideCarAirPlayMacProPatched), "patch size invalid");
+static_assert(sizeof(kSideCarAirPlayMacminiOriginal) == sizeof(kSideCarAirPlayMacminiPatched), "patch size invalid");
 static_assert(sizeof(kSidecariPadModelOriginal) == sizeof(kSidecariPadModelPatched), "patch size invalid");
-static_assert(sizeof(kNightShiftLegacyOriginal) == sizeof(kNightShiftLegacyPatched), "patch size invalid");
-static_assert(sizeof(kNightShiftOriginal) == sizeof(kNightShiftPatched), "patch size invalid");
+static_assert(sizeof(kMacModelAirplayExtendedOriginal) == sizeof(kMacModelAirplayExtendedPatched), "patch size invalid");
+static_assert(sizeof(kAirPlayVmmOriginal) == sizeof(kAirPlayVmmPatched), "patch size invalid");
+static_assert(sizeof(kNightShiftOriginal) == sizeof(kNightShiftPatched), "patch size invalid");

FeatureUnlock/kern_start.cpp

@@ -298,19 +298,18 @@ static void patched_cs_validate_page(vnode_t vp, memory_object_t pager, memory_o
                             }
                         }
                     }
-
-                    // Sidecar iPad check
-                    if (allow_sidecar_ipad && !has_applied_iPad_sidecar_patch) {
-                        patch_result = searchAndPatch(data, PAGE_SIZE, path, kSidecariPadModelOriginal, kSidecariPadModelPatched, "Sidecar (iPad)", true);
-                        if (patch_result) {
-                            has_applied_iPad_sidecar_patch = true;
-                        }
-                    }
-
+                }
+                // Sidecar iPad check
+                if (allow_sidecar_ipad && !has_applied_iPad_sidecar_patch) {
+                    patch_result = searchAndPatch(data, PAGE_SIZE, path, kSidecariPadModelOriginal, kSidecariPadModelPatched, "Sidecar (iPad)", true);
                     if (patch_result) {
-                        return;
+                        has_applied_iPad_sidecar_patch = true;
                     }
                 }
+
+                if (patch_result) {
+                    return;
+                }
             }
         }
         // Individual binary patching
@@ -586,6 +585,11 @@ static void detectSupportedPatchSets() {
         }
     }
     if (!disable_sidecar_mac && (os_supports_sidecar || os_supports_airplay_to_mac || os_supports_universal_control)) {
+        // Sidecar (iPad specific)
+        if (allow_sidecar_ipad) {
+            DBGLOG(MODULE_SHORT, "Model requested Sidecar iPad patch");
+        }
+
         // Sidecar and AirPlay to Mac
         if (// Ivy Bridge to Broadwell (including MacPro5,1)
             model_is_iMac_2012 || model_is_iMac_2013 || model_is_iMac_2014 || model_is_iMac_2015_broadwell || \