GP-4799 Respect ELF Skip Relocation Option

NationalSecurityAgency · Jul 29, 2024 · 8cf1450 · 8cf1450
1 parent 649c182
commit 8cf1450
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Showing 2 changed files with 33 additions and 34 deletions.
diff --git a/...es/Base/src/main/java/ghidra/app/util/bin/format/elf/relocation/ElfRelocationContext.java b/...es/Base/src/main/java/ghidra/app/util/bin/format/elf/relocation/ElfRelocationContext.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -181,7 +181,8 @@ public int getRelrRelocationType() {
 	 * Get a relocation context for a specfic Elf image and relocation table
 	 * @param loadHelper Elf load helper
 	 * @param symbolMap Elf symbol placement map
-	 * @return relocation context object
+	 * @return relocation context object.  A generic context will be returned if a custom one
+	 * is not defined.
 	 */
 	public static ElfRelocationContext<?> getRelocationContext(ElfLoadHelper loadHelper,
 			Map<ElfSymbol, Address> symbolMap) {

diff --git a/Ghidra/Features/Base/src/main/java/ghidra/app/util/opinion/ElfProgramBuilder.java b/Ghidra/Features/Base/src/main/java/ghidra/app/util/opinion/ElfProgramBuilder.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -879,22 +879,21 @@ private void processRelocations(TaskMonitor monitor) throws CancelledException {
 		}
 		monitor.initialize(totalCount);
 
-		ElfRelocationContext context = ElfRelocationContext.getRelocationContext(this, symbolMap);
+		ElfRelocationContext<?> context =
+			ElfRelocationContext.getRelocationContext(this, symbolMap);
 		try {
 			for (ElfRelocationTable relocationTable : relocationTables) {
 				monitor.checkCancelled();
 				processRelocationTable(relocationTable, context, monitor);
 			}
 		}
 		finally {
-			if (context != null) {
-				context.dispose();
-			}
+			context.dispose();
 		}
 	}
 
 	private void processRelocationTable(ElfRelocationTable relocationTable,
-			ElfRelocationContext context, TaskMonitor monitor) throws CancelledException {
+			ElfRelocationContext<?> context, TaskMonitor monitor) throws CancelledException {
 
 		Address defaultBase = getDefaultAddress(elf.adjustAddressForPrelink(0));
 		AddressSpace defaultSpace = defaultBase.getAddressSpace();
@@ -953,12 +952,12 @@ else if (relocationSpace != defaultSpace) {
 	}
 
 	private void processRelocationTableEntries(ElfRelocationTable relocationTable,
-			ElfRelocationContext context, AddressSpace relocationSpace, long baseWordOffset,
+			ElfRelocationContext<?> context, AddressSpace relocationSpace, long baseWordOffset,
 			TaskMonitor monitor) throws CancelledException {
 
-		if (context != null) {
-			context.startRelocationTableProcessing(relocationTable);
-		}
+		boolean processRelocations = ElfLoaderOptionsFactory.performRelocations(options);
+
+		context.startRelocationTableProcessing(relocationTable);
 
 		ElfSymbolTable symbolTable = relocationTable.getAssociatedSymbolTable();
 		ElfRelocation[] relocs = relocationTable.getRelocations();
@@ -977,7 +976,7 @@ private void processRelocationTableEntries(ElfRelocationTable relocationTable,
 
 		boolean relrTypeUnknown = false;
 		int relrRelocationType = 0;
-		if (relocationTable.isRelrTable() && context != null) {
+		if (relocationTable.isRelrTable()) {
 			relrRelocationType = context.getRelrRelocationType();
 			if (relrRelocationType == 0) {
 				relrTypeUnknown = true;
@@ -991,8 +990,8 @@ private void processRelocationTableEntries(ElfRelocationTable relocationTable,
 			monitor.incrementProgress(1);
 
 			int type = reloc.getType();
-			if (type == 0) {
-				continue; // ignore relocation type 0 (i.e., ..._NONE)
+			if (type == 0 && !relocationTable.isRelrTable()) {
+				continue; // ignore relocation type 0 if not a RELR table (i.e., ..._NONE)
 			}
 
 			int symbolIndex = reloc.getSymbolIndex();
@@ -1004,9 +1003,7 @@ private void processRelocationTableEntries(ElfRelocationTable relocationTable,
 			Address baseAddress = relocationSpace.getTruncatedAddress(baseWordOffset, true);
 
 			// relocation offset (r_offset) is defined to be a byte offset (assume byte size is 1)
-			Address relocAddr =
-				context != null ? context.getRelocationAddress(baseAddress, reloc.getOffset())
-						: baseAddress.addWrap(reloc.getOffset());
+			Address relocAddr = context.getRelocationAddress(baseAddress, reloc.getOffset());
 
 			long[] values = new long[] { reloc.getSymbolIndex() };
 
@@ -1018,6 +1015,11 @@ private void processRelocationTableEntries(ElfRelocationTable relocationTable,
 			Status status = Status.SKIPPED;
 			int byteLength = 0;
 			try {
+
+				if (!processRelocations) {
+					continue; // skip and record relocation
+				}
+
 				if (unableToApplyRelocs) {
 					status = Status.FAILURE;
 					context.markRelocationError(relocAddr, type, symbolIndex, symbolName,
@@ -1044,17 +1046,15 @@ private void processRelocationTableEntries(ElfRelocationTable relocationTable,
 					}
 				}
 
-				if (context != null) {
-					if (relrTypeUnknown) {
-						status = Status.UNSUPPORTED;
-						ElfRelocationHandler.bookmarkUnsupportedRelr(program, relocAddr,
-							symbolIndex, symbolName);
-					}
-					else {
-						RelocationResult result = context.processRelocation(reloc, relocAddr);
-						byteLength = result.byteLength();
-						status = result.status();
-					}
+				if (relrTypeUnknown) {
+					status = Status.UNSUPPORTED;
+					ElfRelocationHandler.bookmarkUnsupportedRelr(program, relocAddr, symbolIndex,
+						symbolName);
+				}
+				else {
+					RelocationResult result = context.processRelocation(reloc, relocAddr);
+					byteLength = result.byteLength();
+					status = result.status();
 				}
 			}
 			catch (MemoryAccessException e) {
@@ -1072,9 +1072,7 @@ private void processRelocationTableEntries(ElfRelocationTable relocationTable,
 			}
 		}
 
-		if (context != null) {
-			context.endRelocationTableProcessing();
-		}
+		context.endRelocationTableProcessing();
 	}
 
 	@Override