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GP-3248: MachoLoader now creates thunks on stubs

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This commit is contained in:
Ryan Kurtz
2023-09-22 10:10:51 -04:00
parent af453f8084
commit 0b8365c679
1 changed files with 26 additions and 41 deletions
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67
Ghidra/Features/Base/src/main/java/ghidra/app/util/opinion/MachoProgramBuilder.java
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@@ -124,7 +124,7 @@ public class MachoProgramBuilder {
processEntryPoint(); processEntryPoint();
boolean exportsFound = processExports(machoHeader); boolean exportsFound = processExports(machoHeader);
processSymbolTables(machoHeader, !exportsFound); processSymbolTables(machoHeader, !exportsFound);
processIndirectSymbols(); processStubs();
processUndefinedSymbols(); processUndefinedSymbols();
processAbsoluteSymbols(); processAbsoluteSymbols();
List<Address> chainedFixups = processChainedFixups(machoHeader); List<Address> chainedFixups = processChainedFixups(machoHeader);
@@ -570,19 +570,8 @@ public class MachoProgramBuilder {
} }
} }
protected void processIndirectSymbols() throws Exception { protected void processStubs() throws Exception {
// We only want to directly handle indirect symbols on incomplete dylibs that were extracted monitor.setMessage("Processing stubs...");
// from a dyld_shared_cache. If the Mach-O is fully-formed and contains binding information
// (found in the DyldChainedFixupsCommand or DyldInfoCommand), thunk analysis properly
// associates indirect symbols with their "real" symbol and we shouldn't do anything here.
// We hope to one day include binding information in our extracted dylibs, at which point
// this method can fully go away.
if (machoHeader.getFirstLoadCommand(DyldChainedFixupsCommand.class) != null ||
machoHeader.getFirstLoadCommand(DyldInfoCommand.class) != null) {
return;
}
monitor.setMessage("Processing indirect symbols...");
SymbolTableCommand symbolTableCommand = SymbolTableCommand symbolTableCommand =
machoHeader.getFirstLoadCommand(SymbolTableCommand.class); machoHeader.getFirstLoadCommand(SymbolTableCommand.class);
@@ -598,24 +587,14 @@ public class MachoProgramBuilder {
return; return;
} }
List<Integer> sectionTypes = List.of(SectionTypes.S_NON_LAZY_SYMBOL_POINTERS, for (Section section : machoHeader.getAllSections()) {
SectionTypes.S_LAZY_SYMBOL_POINTERS, SectionTypes.S_SYMBOL_STUBS);
List<Section> sections = machoHeader.getAllSections()
.stream()
.filter(s -> sectionTypes.contains(s.getType()))
.toList();
for (Section section : sections) {
if (monitor.isCancelled()) { if (monitor.isCancelled()) {
return; return;
} }
if (section.getSize() == 0) { if (section.getSize() == 0 || section.getType() != SectionTypes.S_SYMBOL_STUBS) {
continue; continue;
} }
Namespace namespace = createNamespace(section.getSectionName());
int indirectSymbolTableIndex = section.getReserved1(); int indirectSymbolTableIndex = section.getReserved1();
int symbolSize = machoHeader.getAddressSize(); int symbolSize = machoHeader.getAddressSize();
@@ -632,19 +611,19 @@ public class MachoProgramBuilder {
} }
int symbolIndex = indirectSymbols[i]; int symbolIndex = indirectSymbols[i];
NList symbol = symbolTableCommand.getSymbolAt(symbolIndex); NList symbol = symbolTableCommand.getSymbolAt(symbolIndex);
if (symbol != null) { if (symbol == null) {
String name = SymbolUtilities.replaceInvalidChars(symbol.getString(), true); continue;
if (name != null && name.length() > 0) { }
try { String name = SymbolUtilities.replaceInvalidChars(symbol.getString(), true);
program.getSymbolTable() if (name != null && name.length() > 0) {
.createLabel(startAddr, name, namespace, SourceType.IMPORTED); Function stubFunc = createOneByteFunction(name, startAddr);
} if (stubFunc != null) {
catch (Exception e) { ExternalLocation loc = program.getExternalManager()
log.appendMsg("Unable to create indirect symbol " + name); .addExtLocation(Library.UNKNOWN, name, null, SourceType.IMPORTED);
log.appendException(e); stubFunc.setThunkedFunction(loc.createFunction());
}
} }
} }
startAddr = startAddr.add(symbolSize); startAddr = startAddr.add(symbolSize);
} }
} }
@@ -1511,14 +1490,19 @@ public class MachoProgramBuilder {
* *
* @param name the name of the function * @param name the name of the function
* @param address location to create the function * @param address location to create the function
* @return If a function already existed at the given address, that function will be returned.
* Otherwise, the newly created function will be returned. If there was a problem creating
* the function, null will be returned.
*/ */
void createOneByteFunction(String name, Address address) { Function createOneByteFunction(String name, Address address) {
FunctionManager functionMgr = program.getFunctionManager(); FunctionManager functionMgr = program.getFunctionManager();
if (functionMgr.getFunctionAt(address) != null) { Function function = functionMgr.getFunctionAt(address);
return; if (function != null) {
return function;
} }
try { try {
functionMgr.createFunction(name, address, new AddressSet(address), SourceType.IMPORTED); return functionMgr.createFunction(name, address, new AddressSet(address),
SourceType.IMPORTED);
} }
catch (InvalidInputException e) { catch (InvalidInputException e) {
// ignore // ignore
@@ -1526,6 +1510,7 @@ public class MachoProgramBuilder {
catch (OverlappingFunctionException e) { catch (OverlappingFunctionException e) {
// ignore // ignore
} }
return null;
} }
/** /**