From 7135527b92f6a11524715ad91d45ae9bf3356e6c Mon Sep 17 00:00:00 2001
From: Graham Chapman <graham_chapman@ca.ibm.com>
Date: Tue, 12 Mar 2019 19:29:45 -0400
Subject: [PATCH] Fix incorrect iTable build

The iTable building code was considering all methods in the interface
class, not just the ones that are appropriate for the iTable. This
results in an incorrect iTable shape (and very possibly writing off the
end of the allocated iTable chunk).

Process only methods from the interface which make up the interface
contract (public methods that appear in the vTable).

[ci skip]

Signed-off-by: Graham Chapman <graham_chapman@ca.ibm.com>
---
 runtime/vm/createramclass.cpp | 65 ++++++++++++++++++-----------------
 1 file changed, 33 insertions(+), 32 deletions(-)

diff --git a/runtime/vm/createramclass.cpp b/runtime/vm/createramclass.cpp
index 1ae5a0e2683..ddd2c69917a 100644
--- a/runtime/vm/createramclass.cpp
+++ b/runtime/vm/createramclass.cpp
@@ -297,43 +297,44 @@ addITableMethods(J9VMThread* vmStruct, J9Class *ramClass, J9Class *interfaceClas
 		J9Method *interfaceRamMethod = interfaceClass->ramMethods;
 		while (count-- > 0) {
 			J9ROMMethod *interfaceRomMethod = J9_ROM_METHOD_FROM_RAM_METHOD(interfaceRamMethod);
-			J9UTF8 *interfaceMethodName = J9ROMMETHOD_NAME(interfaceRomMethod);
-			J9UTF8 *interfaceMethodSig = J9ROMMETHOD_SIGNATURE(interfaceRomMethod);
-			UDATA vTableOffset = 0;
-			UDATA searchIndex = 0;
+			if (J9ROMMETHOD_IN_ITABLE(interfaceRomMethod)) {
+				J9UTF8 *interfaceMethodName = J9ROMMETHOD_NAME(interfaceRomMethod);
+				J9UTF8 *interfaceMethodSig = J9ROMMETHOD_SIGNATURE(interfaceRomMethod);
+				UDATA vTableOffset = 0;
+				UDATA searchIndex = 0;
 			
-			/* Search the vTable for a public method of the correct name. */
-			while (searchIndex < vTableSize) {
-				J9Method *vTableRamMethod = vTable[searchIndex];
-				J9ROMMethod *vTableRomMethod = J9_ROM_METHOD_FROM_RAM_METHOD(vTableRamMethod);
-
-				if (J9ROMMETHOD_IN_ITABLE(vTableRomMethod)) {
-					J9UTF8 *vTableMethodName = J9ROMMETHOD_NAME(vTableRomMethod);
-					J9UTF8 *vTableMethodSig = J9ROMMETHOD_SIGNATURE(vTableRomMethod);
-
-					if ((J9UTF8_LENGTH(interfaceMethodName) == J9UTF8_LENGTH(vTableMethodName))
-					&& (J9UTF8_LENGTH(interfaceMethodSig) == J9UTF8_LENGTH(vTableMethodSig))
-					&& (memcmp(J9UTF8_DATA(interfaceMethodName), J9UTF8_DATA(vTableMethodName), J9UTF8_LENGTH(vTableMethodName)) == 0)
-					&& (memcmp(J9UTF8_DATA(interfaceMethodSig), J9UTF8_DATA(vTableMethodSig), J9UTF8_LENGTH(vTableMethodSig)) == 0)
-					) {
-						/* fill in interface index --> vTableOffset mapping */
-						vTableOffset = J9VTABLE_OFFSET_FROM_INDEX(searchIndex);
-						**currentSlot = vTableOffset;
-						(*currentSlot)++;
-						break;
+				/* Search the vTable for a public method of the correct name. */
+				while (searchIndex < vTableSize) {
+					J9Method *vTableRamMethod = vTable[searchIndex];
+					J9ROMMethod *vTableRomMethod = J9_ROM_METHOD_FROM_RAM_METHOD(vTableRamMethod);
+
+					if (J9ROMMETHOD_IN_ITABLE(vTableRomMethod)) {
+						J9UTF8 *vTableMethodName = J9ROMMETHOD_NAME(vTableRomMethod);
+						J9UTF8 *vTableMethodSig = J9ROMMETHOD_SIGNATURE(vTableRomMethod);
+
+						if ((J9UTF8_LENGTH(interfaceMethodName) == J9UTF8_LENGTH(vTableMethodName))
+						&& (J9UTF8_LENGTH(interfaceMethodSig) == J9UTF8_LENGTH(vTableMethodSig))
+						&& (memcmp(J9UTF8_DATA(interfaceMethodName), J9UTF8_DATA(vTableMethodName), J9UTF8_LENGTH(vTableMethodName)) == 0)
+						&& (memcmp(J9UTF8_DATA(interfaceMethodSig), J9UTF8_DATA(vTableMethodSig), J9UTF8_LENGTH(vTableMethodSig)) == 0)
+						) {
+							/* fill in interface index --> vTableOffset mapping */
+							vTableOffset = J9VTABLE_OFFSET_FROM_INDEX(searchIndex);
+							**currentSlot = vTableOffset;
+							(*currentSlot)++;
+							break;
+						}
 					}
+					searchIndex++;
 				}
-				searchIndex++;
-			}
 
 #if defined(J9VM_TRACE_ITABLE)
-			{
-				PORT_ACCESS_FROM_VMC(vmStruct);
-				j9tty_printf(PORTLIB, "\n  map %.*s%.*s to vTableOffset=%d (%d)", J9UTF8_LENGTH(interfaceMethodName),
-						J9UTF8_DATA(interfaceMethodName), J9UTF8_LENGTH(interfaceMethodSig), J9UTF8_DATA(interfaceMethodSig), vTableOffset, searchIndex);
-			}
+				{
+					PORT_ACCESS_FROM_VMC(vmStruct);
+					j9tty_printf(PORTLIB, "\n  map %.*s%.*s to vTableOffset=%d (%d)", J9UTF8_LENGTH(interfaceMethodName),
+							J9UTF8_DATA(interfaceMethodName), J9UTF8_LENGTH(interfaceMethodSig), J9UTF8_DATA(interfaceMethodSig), vTableOffset, searchIndex);
+				}
 #endif
-
+			}
 			interfaceRamMethod++;
 		}
 	}
@@ -462,7 +463,7 @@ addInterfaceMethods(J9VMThread *vmStruct, J9ClassLoader *classLoader, J9Class *i
 		for (j=0; j < count; j++) {
 			J9ROMMethod *romMethod = J9_ROM_METHOD_FROM_RAM_METHOD(interfaceMethod);
 			/* Ignore the <clinit> from the interface class. */
-			if (J9_ARE_NO_BITS_SET(romMethod->modifiers, J9AccPrivate | J9AccStatic)) {
+			if (J9ROMMETHOD_IN_ITABLE(romMethod)) {
 				J9UTF8 *interfaceMethodNameUTF = J9ROMMETHOD_NAME(romMethod);
 				J9UTF8 *interfaceMethodSigUTF = J9ROMMETHOD_SIGNATURE(romMethod);
 				UDATA tempIndex = vTableMethodCount;