GP-4376 Updated gcc class recovery to allow for special typeinfos that

are not in program memory or external block. Also updated to add a check
for unhandled relocations. Also updated to allow for non-mangled
typeinfo-name strings.

Ghidra/Features/Decompiler/ghidra_scripts/RecoverClassesFromRTTIScript.java

@@ -80,6 +80,7 @@
 import ghidra.program.model.listing.*;
 import ghidra.program.model.mem.MemoryBlock;
 import ghidra.program.model.reloc.Relocation;
+import ghidra.program.model.reloc.Relocation.Status;
 import ghidra.program.model.reloc.RelocationTable;
 import ghidra.program.model.symbol.Symbol;
 import ghidra.program.util.GhidraProgramUtilities;
@@ -210,8 +211,7 @@ else if (isPE() && isGcc()) {
  if (!runGcc) {
  return;
  }
- //run fixup old elf relocations script
- runScript("FixElfExternalOffsetDataRelocationScript.java");
+
  recoverClassesFromRTTI = new RTTIGccClassRecoverer(currentProgram, state.getTool(),
  this, BOOKMARK_FOUND_FUNCTIONS, USE_SHORT_TEMPLATE_NAMES_IN_STRUCTURE_FIELDS,
  nameVfunctions, hasDebugSymbols, monitor);
@@ -232,9 +232,6 @@ else if (isGcc()) {
  return;
  }
 
- //run fixup old elf relocations script
- runScript("FixElfExternalOffsetDataRelocationScript.java");
-
  hasDebugSymbols = isDwarfLoadedInProgram();
  if (hasDwarf() && !hasDebugSymbols) {
  println(
@@ -379,7 +376,7 @@ private boolean isDwarfLoadedInProgram() {
  DWARFProgram.DWARF_ROOT_NAME) || options.getBoolean("DWARF Loaded", false));
  }
 
- public String validate() throws CancelledException {
+ public String validate() throws Exception {
 
  if (currentProgram == null) {
  return ("There is no open program");
@@ -417,6 +414,8 @@ public String validate() throws CancelledException {
  // check that gcc loader or mingw analyzer has fixed the relocations correctly
  if (isGcc()) {
 
+ runScript("FixElfExternalOffsetDataRelocationScript.java");
+
  // first check that there is even rtti by searching the special string in memory
  if (!isStringInProgramMemory("class_type_info")) {
  return ("This program does not contain RTTI.");
@@ -432,7 +431,7 @@ public String validate() throws CancelledException {
  "contact the Ghidra team so this issue can be fixed.");
  }
 
- if (hasUnhandledRelocations()) {
+ if (hasRelocationIssue()) {
  return ("This program has unhandled elf relocations so cannot continue. Please " +
  "contact the Ghidra team for assistance.");
  }
@@ -442,7 +441,13 @@ public String validate() throws CancelledException {
 
  }
 
- private boolean hasUnhandledRelocations() throws CancelledException {
+ /**
+ * Method to determine if the gcc relocations needed to find the special typeinfos/vtables 
+ * have any issues that would keep script from running correctly.
+ * @return true if there are any issues with the relocations, false otherwise
+ * @throws CancelledException if cancelled
+ */
+ private boolean hasRelocationIssue() throws CancelledException {
 
  RelocationTable relocationTable = currentProgram.getRelocationTable();
 
@@ -452,17 +457,39 @@ private boolean hasUnhandledRelocations() throws CancelledException {
  monitor.checkCancelled();
  Relocation r = relocations.next();
 
- if (r.getSymbolName().contains("class_type_info") &&
- (r.getStatus() != Relocation.Status.APPLIED &&
- r.getStatus() != Relocation.Status.APPLIED_OTHER &&
- r.getStatus() != Relocation.Status.SKIPPED)) {
- return true;
- }
+ String symbolName = r.getSymbolName();
+
+ if (symbolName != null && symbolName.contains("class_type_info")) {
+
+ Status status = r.getStatus();
 
+ // if any relocations for special typeinfo class symbols have failed then there
+ // is an issue
+ if (status == Status.FAILURE) {
+ return true;
+ }
+
+ // if any relocations for special typeinfo class symbols are unsupported then
+ // determine where the symbol is located before determining if it is an issue
+ if(status == Status.UNSUPPORTED) {
+
+ //if relocation symbol is the same as the symbol at the relcation address
+ //then this situation is not an issue - it indicates a copy relocation at the
+ //location of the special typeinfo vtable which is a use case that can be handled
+ Address address = r.getAddress();
+ Symbol symbolAtAddress = currentProgram.getSymbolTable().getSymbol(symbolName, address, currentProgram.getGlobalNamespace());
+ if(symbolAtAddress != null) {
+ continue;
+ }
+ return true;
+ }
+
+ }
  }
  return false;
  }
 
+
  private void analyzeProgramChanges(AddressSetView beforeChanges) throws Exception {
 
  AddressSetView addressSet = currentProgram.getChanges().getAddressSet();

Ghidra/Features/Decompiler/ghidra_scripts/classrecovery/GccTypeinfo.java

@@ -15,10 +15,7 @@
  */
 package classrecovery;
 
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
+import java.util.*;
 
 import ghidra.program.model.address.Address;
 import ghidra.program.model.symbol.Namespace;
@@ -30,7 +27,7 @@ public class GccTypeinfo extends Typeinfo {
  private static final String VMI_CLASS_TYPEINFO_NAMESPACE = "__vmi_class_type_info";
 
  boolean isSpecialTypeinfo;
- GccTypeinfo inheritedSpecialTypeinfo = null; 
+ Namespace inheritedSpecialTypeinfoNamespace = null;
  Address vtableAddress;
  boolean inProgramMemory;
  String mangledNamespaceString = null;
@@ -53,13 +50,13 @@ public boolean isInProgramMemory() {
  return inProgramMemory;
  }
 
- public void setInheritedSpecialTypeinfo(GccTypeinfo specialTypeinfo) {
- inheritedSpecialTypeinfo = specialTypeinfo;
+ public void setInheritedSpecialTypeinfoNamespace(Namespace specialTypeinfoNamespace) {
+ inheritedSpecialTypeinfoNamespace = specialTypeinfoNamespace;
  }
 
 
- public GccTypeinfo getInheritedSpecialTypeinfo() {
- return inheritedSpecialTypeinfo;
+ public Namespace getInheritedSpecialTypeinfoNamespace() {
+ return inheritedSpecialTypeinfoNamespace;
  }
 
 
@@ -156,21 +153,21 @@ public long getInheritanceFlagValue() {
  }
 
  public boolean isClassTypeinfo() {
- if(inheritedSpecialTypeinfo.getNamespace().getName().equals(CLASS_TYPEINFO_NAMESPACE)) {
+ if (inheritedSpecialTypeinfoNamespace.getName().equals(CLASS_TYPEINFO_NAMESPACE)) {
  return true;
  }
  return false;
  }
 
  public boolean isSiClassTypeinfo() {
- if(inheritedSpecialTypeinfo.getNamespace().getName().equals(SI_CLASS_TYPEINFO_NAMESPACE)) {
+ if (inheritedSpecialTypeinfoNamespace.getName().equals(SI_CLASS_TYPEINFO_NAMESPACE)) {
  return true;
  }
  return false;
  }
 
  public boolean isVmiClassTypeinfo() {
- if(inheritedSpecialTypeinfo.getNamespace().getName().equals(VMI_CLASS_TYPEINFO_NAMESPACE)) {
+ if (inheritedSpecialTypeinfoNamespace.getName().equals(VMI_CLASS_TYPEINFO_NAMESPACE)) {
  return true;
  }
  return false;