OcAppleKernelLib: Fix KPI handling in 10.6 prelinkedkernel

Resolves issues injecting AppleIntelE1000e.kext referencing IOLockLock
acidanthera · Aug 26, 2020 · 520d27d · 520d27d
1 parent d2230ec
commit 520d27d
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Showing 3 changed files with 41 additions and 12 deletions.
diff --git a/Library/OcAppleKernelLib/KxldState.c b/Library/OcAppleKernelLib/KxldState.c
@@ -307,8 +307,13 @@ InternalKxldStateBuildLinkedVtables (
     &NumVtables
     );
 
+  //
+  // Some KPIs may not have vtables (e.g. BSD).
+  //
   if (KxldVtables == NULL) {
-    return EFI_UNSUPPORTED;
+    Kext->LinkedVtables   = NULL;
+    Kext->NumberOfVtables = 0;
+    return EFI_SUCCESS;
   }
 
   NumEntries = 0;

diff --git a/Library/OcAppleKernelLib/Link.c b/Library/OcAppleKernelLib/Link.c
@@ -1418,11 +1418,19 @@ InternalPrelinkKext64 (
     if (!Result) {
       DEBUG ((
         DEBUG_INFO,
-        "OCAK: Symbol %s was unresolved for kext %a\n",
+        "OCAK: Symbol %a was unresolved for kext %a\n",
         MachoGetSymbolName64 (MachoContext, Symbol),
         Kext->Identifier
         ));
       return EFI_LOAD_ERROR;
+    } else {
+      DEBUG ((
+        DEBUG_VERBOSE,
+        "OCAK: Symbol %a was resolved for kext %a to %Lx\n",
+        MachoGetSymbolName64 (MachoContext, Symbol),
+        Kext->Identifier,
+        Symbol->Value
+        ));
     }
   }
   //

diff --git a/Library/OcAppleKernelLib/PrelinkedKext.c b/Library/OcAppleKernelLib/PrelinkedKext.c
@@ -63,6 +63,8 @@ InternalCreatePrelinkedKext (
   UINT32                   KxldStateSize;
   UINT32                   ContainerOffset;
   BOOLEAN                  Found;
+  BOOLEAN                  HasExe;
+  BOOLEAN                  IsKpi;
 
   KextIdentifier    = NULL;
   BundleLibraries   = NULL;
@@ -154,17 +156,22 @@ InternalCreatePrelinkedKext (
   //
   // BundleLibraries, CompatibleVersion, and KmodInfo are optional and thus not checked.
   //
-  if (!Found
-    || KextIdentifier == NULL
-    || SourceBase < VirtualBase
-    || (Prelinked != NULL
-      && (VirtualBase == 0
-        || SourceBase == 0
-        || SourceSize == 0
-        || SourceSize > MAX_UINT32))) {
+  if (!Found || KextIdentifier == NULL || SourceBase < VirtualBase) {
     return NULL;
   }
 
+  //
+  // KPIs on 10.6.8 may not have executables, but for all other types they are required.
+  //
+  if (Prelinked != NULL) {
+    HasExe = VirtualBase != 0 && SourceBase != 0 && SourceSize != 0 && SourceSize <= MAX_UINT32;
+    IsKpi  = VirtualBase == 0 && SourceBase == 0 && SourceSize == 0
+      && KxldState != 0 && KxldStateSize != 0 && !Prelinked->IsKernelCollection;
+    if (!IsKpi && !HasExe) {
+      return NULL;
+    }
+  }
+
   if (Prelinked != NULL && Prelinked->IsKernelCollection) {
     CalculatedSourceSize = KcGetKextSize (Prelinked, SourceBase);
     if (CalculatedSourceSize < MAX_UINT32 && CalculatedSourceSize > SourceSize) {
@@ -179,7 +186,7 @@ InternalCreatePrelinkedKext (
     }
   }
 
-  if (Prelinked != NULL) {
+  if (Prelinked != NULL && HasExe) {
     if (Prelinked->IsKernelCollection) {
       BaseSegment = Prelinked->RegionSegment;
     } else {
@@ -208,6 +215,7 @@ InternalCreatePrelinkedKext (
   }
 
   if (Prelinked != NULL
+    && HasExe
     && !MachoInitializeContext (&NewKext->Context.MachContext, &Prelinked->Prelinked[SourceBase], (UINT32)SourceSize, ContainerOffset)) {
     FreePool (NewKext);
     return NULL;
@@ -236,6 +244,14 @@ InternalCreatePrelinkedKext (
     }
   }
 
+  DEBUG ((
+    DEBUG_VERBOSE,
+    "OCAK: %a got KXLD %p %u\n",
+    NewKext->Identifier,
+    NewKext->Context.KxldState,
+    NewKext->Context.KxldStateSize
+    ));
+
   return NewKext;
 }
 
@@ -887,7 +903,7 @@ InternalScanPrelinkedKext (
       // _PrelinkExecutableLoadAddr / _PrelinkExecutableSourceAddr values equal to MAX_INT64.
       // Skip them early to improve performance.
       //
-      if ((Context->IsKernelCollection || Context->PrelinkedStateSegment != NULL)
+      if (Context->IsKernelCollection
         && AsciiStrnCmp (DependencyId, "com.apple.kpi.", L_STR_LEN ("com.apple.kpi.")) == 0) {
         DEBUG ((DEBUG_VERBOSE, "OCAK: Ignoring KPI %a for kext %a in KC/state mode\n", DependencyId, Kext->Identifier));
         continue;