Merge remote-tracking branch 'origin/GP-5411_emteere_PPCpltThunk' into patch

Ghidra/Features/Base/src/main/java/ghidra/app/cmd/function/CreateThunkFunctionCmd.java

@@ -15,6 +15,8 @@
  */
 package ghidra.app.cmd.function;
 
+import static ghidra.program.model.symbol.RefType.*;
+
 import java.math.BigInteger;
 import java.util.*;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -732,13 +734,41 @@ public class CreateThunkFunctionCmd extends BackgroundCommand<Program> {
 			FlowType flowType, boolean checkForSideEffects, HashSet<Varnode> setRegisters,
 			HashSet<Varnode> usedRegisters) {
 
-		// conditional jumps can't be thunks.
+		// conditional jumps/call terminators can't be thunks,
-		// any other flow, not good
+		// unless not checkingForSideEffects and just trying to get possible thunk address.
-		Address flowingAddr = null;
-		if ((flowType.isJump() || flowType.equals(RefType.COMPUTED_CALL_TERMINATOR) ||
-			flowType.equals(RefType.CALL_TERMINATOR)) && !flowType.isConditional()) {
-			// program counter should be assumed to be used
 		
+		boolean isJump = flowType.isJump();
+		boolean isCall = flowType.isCall();
+		boolean isConditional = flowType.isConditional();
+		
+		// only jump/call are allowed
+		if (!(isJump || isCall)) {
+			return null;
+		}
+		
+		// no conditional jumps allowed
+		if (isJump && isConditional) {
+			return null;
+		}
+		
+		if (isCall) {
+			// Any conditional call considered as having side-effects
+			if (isConditional && checkForSideEffects) {
+				return null;
+			}
+			// CALL_TERMINATOR, COMPUTED_CALL_TERMINATOR
+			else if (!flowType.isTerminal()) {
+				if (flowType == COMPUTED_CALL ||
+					flowType == UNCONDITIONAL_CALL) {
+					// consider any simple call having side-effects
+					if (checkForSideEffects) {
+						return null;
+					}
+				}
+			}
+		}
+		
+		// program counter should be assumed to be used
 		// assume PC is used when considering registers that have been set
 		Register PC = program.getLanguage().getProgramCounter();
 		if (PC != null) {
@@ -757,11 +787,13 @@ public class CreateThunkFunctionCmd extends BackgroundCommand<Program> {
 			}
 		}
 
+		Address flowingAddr = null;
+		
 		// if not checking for sideEffect registers set, or there are no side-effects
 		if (!checkForSideEffects || setRegisters.size() == 0) {
 			flowingAddr = getFlowingAddress(program, instr);
 		}
-		}
+		
 		return flowingAddr;
 	}
 

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/function/EditThunkFunctionAction.java

@@ -72,22 +72,30 @@ class EditThunkFunctionAction extends ProgramContextAction {
 		if (func == null) {
 			return;
 		}
+		Address funcEntry = func.getEntryPoint();
 
 		Function refFunc = func.getThunkedFunction(false);		
+		if (refFunc == null) {
+			// if not already thunked, fill in a possible value from functions instructions
+			Address thunkAddr = CreateThunkFunctionCmd.getThunkedAddr(program, funcEntry, false);
+			if (thunkAddr != null) {
+				refFunc = functionMgr.getFunctionAt(thunkAddr);
+			}
+		}		
+		Symbol refSymbol = (refFunc == null ? null : refFunc.getSymbol());
 
 		// Prompt for function referenced by thunk
 		ThunkReferenceAddressDialog dialog = new ThunkReferenceAddressDialog(funcPlugin.getTool());
-		dialog.showDialog(program, func.getEntryPoint(),
+		dialog.showDialog(program, funcEntry, refSymbol);
-			refFunc != null ? refFunc.getSymbol() : null);
 		Symbol referencedSymbol = dialog.getSymbol();
 		Address referencedFunctionAddr = dialog.getAddress();
 
 		CreateThunkFunctionCmd cmd;
 		if (referencedSymbol != null) {
-			cmd = new CreateThunkFunctionCmd(func.getEntryPoint(), null, referencedSymbol);
+			cmd = new CreateThunkFunctionCmd(funcEntry, null, referencedSymbol);
 		}
 		else if (referencedFunctionAddr != null) {
-			cmd = new CreateThunkFunctionCmd(func.getEntryPoint(), null, referencedFunctionAddr);
+			cmd = new CreateThunkFunctionCmd(funcEntry, null, referencedFunctionAddr);
 		}
 		else {
 			return; // cancelled

Ghidra/Processors/PowerPC/data/patterns/PPC_BE_patterns.xml

@@ -36,4 +36,31 @@
       <possiblefuncstart validcode="function" label="__get_pc_thunk_lr" /> <!-- must be a function here -->
   </pattern>
   
+  <pattern> <!-- .plt entry thunk -->
+      <data>
+	    0xf8410028                           <!-- std     r2,0x28(r1) -->
+        001111.. ...00010 0xff 0xff          <!-- subis  rX,r2,0x1 -->
+	    0xe9 ........ ........ ........      <!-- ld      rX,#(x) -->
+	    0x7d 0x.9 0x03 0xa6                  <!-- mtctr   rX -->
+	    0xe8 010..... ........ ........      <!-- ld      r2,#(x) -->
+	    0x28220000                           <!-- cmpldi  r2,0 -->
+	    0x4c 1..00010 0x04 0x20              <!-- bnectr+ -->
+	    010010.. ........ ........ ......00  <!-- b X@plt -->  
+      </data>
+      <funcstart after="defined" thunk="true"/> <!-- must be something define before this -->
+  </pattern>
+
+  <pattern> <!-- .plt entry thunk -->
+      <data>  
+  		0xf8410028                           <!-- std     r2,0x28(r1) -->
+        0xe9 ........ ........ ........      <!-- ld      rX,#(x) -->
+        0x7d 0x.9 0x03 0xa6                  <!-- mtctr   rX -->
+        0xe8 010..... ........ ........      <!-- ld      r2,#(x) -->
+        0x28220000                           <!-- cmpldi  r2,0 -->
+        0x4c 1..00010 0x04 0x20              <!-- bnectr+ -->
+        010010.. ........ ........ ......00  <!-- b X@plt -->
+      </data>
+      <funcstart after="defined" thunk="true"/> <!-- must be something define before this -->
+  </pattern>
+  
 </patternlist>

Ghidra/Processors/PowerPC/data/patterns/PPC_LE_patterns.xml

@@ -36,4 +36,31 @@
       <possiblefuncstart validcode="function" label="__get_pc_thunk_lr" /> <!-- must be a function here -->
   </pattern>
 
+  <pattern> <!-- .plt entry thunk -->
+      <data>
+	    0x280041f8                           <!-- std     r2,0x28(r1) -->
+	    0xff 0xff ...00010 001111..          <!-- subis  rX,r2,0x1 -->
+	    ........ ........ ........ 0xe9      <!-- ld      rX,#(x) -->
+	    0xa6 0x03 0x.9 0x7d                  <!-- mtctr   rX -->
+	    ........ ........ 010..... 0xe8      <!-- ld      r2,#(x) -->
+	    0x00002228                           <!-- cmpldi  r2,0 -->
+	    0x20 0x04 1..00010 0x4c              <!-- bnectr+ -->
+	    ......00 ........ ........ 010010..  <!-- b X@plt -->  
+      </data>
+      <funcstart after="defined" thunk="true"/> <!-- must be something define before this -->
+  </pattern>
+
+  <pattern> <!-- .plt entry thunk -->
+      <data>  
+	    0x280041f8                           <!-- std     r2,0x28(r1) -->
+	    ........ ........ ........ 0xe9      <!-- ld      rX,#(x) -->
+	    0xa6 0x03 0x.9 0x7d                  <!-- mtctr   rX -->
+	    ........ ........ 010..... 0xe8      <!-- ld      r2,#(x) -->
+	    0x00002228                           <!-- cmpldi  r2,0 -->
+	    0x20 0x04 1..00010 0x4c              <!-- bnectr+ -->
+	    ......00 ........ ........ 010010..  <!-- b X@plt -->  
+      </data>
+      <funcstart after="defined" thunk="true"/> <!-- must be something define before this -->
+  </pattern>
+  
 </patternlist>