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Merge branch 'GP-252_ghidra1_ELF_DT_JMPREL_and_Externals' into Ghidra_9.2

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This commit is contained in:
ghidra1 2020-10-09 16:54:18 -04:00
commit 63be47d026
4 changed files with 71 additions and 10 deletions
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49
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/elf/ElfDefaultGotPltMarkup.java
View File

@ -26,6 +26,7 @@ import ghidra.program.model.mem.Memory;
import ghidra.program.model.mem.MemoryBlock;
import ghidra.program.model.symbol.*;
import ghidra.program.model.util.CodeUnitInsertionException;
import ghidra.util.Msg;
import ghidra.util.exception.*;
import ghidra.util.task.TaskMonitor;
@ -61,8 +62,8 @@ public class ElfDefaultGotPltMarkup {
}
else {
processGOTSections(monitor);
processPLTSection(monitor);
}
processPLT(monitor);
}
/**
@ -73,10 +74,9 @@ public class ElfDefaultGotPltMarkup {
private void processGOTSections(TaskMonitor monitor) throws CancelledException {
// look for .got section blocks
MemoryBlock[] blocks = memory.getBlocks();
for (int i = 0; i < blocks.length; i++) {
for (MemoryBlock gotBlock : blocks) {
monitor.checkCanceled();
MemoryBlock gotBlock = blocks[i];
if (!gotBlock.getName().startsWith(ElfSectionHeaderConstants.dot_got)) {
continue;
}
@ -137,6 +137,7 @@ public class ElfDefaultGotPltMarkup {
Address gotEnd = defaultSpace.getAddress(
firstGotEntryOffset + (count * defaultSpace.getPointerSize()) - 1);
processGOT(gotStart, gotEnd, monitor);
processDynamicPLT(gotStart, gotEnd, monitor);
}
catch (NotFoundException e) {
throw new AssertException(e);
@ -198,7 +199,7 @@ public class ElfDefaultGotPltMarkup {
}
}
private void processPLT(TaskMonitor monitor) throws CancelledException {
private void processPLTSection(TaskMonitor monitor) throws CancelledException {
// TODO: Handle case where PLT is non-executable pointer table
@ -227,16 +228,48 @@ public class ElfDefaultGotPltMarkup {
processLinkageTable(ElfSectionHeaderConstants.dot_plt, minAddress, maxAddress, monitor);
}
private void processDynamicPLT(Address gotStart, Address gotEnd, TaskMonitor monitor)
throws CancelledException {
Address pltStart = null;
Address pltEnd = null;
for (Data gotPtr : listing.getDefinedData(new AddressSet(gotStart.next(), gotEnd), true)) {
monitor.checkCanceled();
if (!gotPtr.isPointer()) {
Msg.error(this, "ELF PLTGOT contains non-pointer");
return; // unexpected
}
Address ptr = (Address) gotPtr.getValue();
if (ptr.getOffset() == 0) {
continue;
}
MemoryBlock block = memory.getBlock(ptr);
if (block == null || block.getName().equals(MemoryBlock.EXTERNAL_BLOCK_NAME)) {
continue;
}
if (pltStart == null) {
pltStart = ptr;
}
pltEnd = ptr;
}
if (pltStart != null) {
processLinkageTable("PLT", pltStart, pltEnd, monitor);
}
}
/**
* Perform disassembly and markup of specified external linkage table which
* consists of thunks to external functions. If symbols are defined within the
* linkage table, these will be transitioned to external functions.
* @param pltName name of PLT section for log messages
* @param minAddress minimum address of linkage table
* @param maxAddress maximum address of linkage table
* @param monitor task monitor
* @throws CancelledException task cancelled
*/
public void processLinkageTable(String name, Address minAddress, Address maxAddress,
public void processLinkageTable(String pltName, Address minAddress, Address maxAddress,
TaskMonitor monitor) throws CancelledException {
// Disassemble section.
@ -248,7 +281,7 @@ public class ElfDefaultGotPltMarkup {
// This can be seen with ARM Android examples.
int count = convertSymbolsToExternalFunctions(minAddress, maxAddress);
if (count > 0) {
log("Converted " + count + " " + name + " section symbols to external thunks");
log("Converted " + count + " " + pltName + " section symbols to external thunks");
}
}
@ -348,8 +381,8 @@ public class ElfDefaultGotPltMarkup {
private void removeMemRefs(Data data) {
if (data != null) {
Reference[] refs = data.getValueReferences();
for (int i = 0; i < refs.length; i++) {
RemoveReferenceCmd cmd = new RemoveReferenceCmd(refs[i]);
for (Reference ref : refs) {
RemoveReferenceCmd cmd = new RemoveReferenceCmd(ref);
cmd.applyTo(data.getProgram());
}
}

12
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/elf/ElfHeader.java
View File

@ -353,6 +353,18 @@ public class ElfHeader implements StructConverter, Writeable {
parseDynamicRelocTable(relocationTableList, ElfDynamicType.DT_RELA,
ElfDynamicType.DT_RELAENT, ElfDynamicType.DT_RELASZ, true);
if (dynamicTable.containsDynamicValue(ElfDynamicType.DT_PLTREL)) {
try {
boolean isRela = (dynamicTable
.getDynamicValue(ElfDynamicType.DT_PLTREL) == ElfDynamicType.DT_RELA.value);
parseDynamicRelocTable(relocationTableList, ElfDynamicType.DT_JMPREL,
null, ElfDynamicType.DT_PLTRELSZ, isRela);
}
catch (NotFoundException e) {
// ignore - skip (required dynamic table value is missing)
}
}
// Android versions
parseDynamicRelocTable(relocationTableList, ElfDynamicType.DT_ANDROID_REL, null,
ElfDynamicType.DT_ANDROID_RELSZ, false);

13
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/elf/ElfRelocation.java
View File

@ -318,6 +318,19 @@ public class ElfRelocation implements ByteArrayConverter, StructConverter {
return struct;
}
/**
* Get the standard relocation size when one has notbeen specified
* @param is64bit true if ELF 64-bit
* @param hasAddend true if relocation has addend
* @return size of relocation entry
*/
public static int getStandardRelocationEntrySize(boolean is64bit, boolean hasAddend) {
if (is64bit) {
return hasAddend ? 24 : 16;
}
return hasAddend ? 12 : 8;
}
/**
* @see ghidra.app.util.bin.ByteArrayConverter#toBytes(ghidra.util.DataConverter)
*/

7
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/elf/ElfRelocationTable.java
View File

@ -128,6 +128,9 @@ public class ElfRelocationTable implements ElfFileSection, ByteArrayConverter {
throws IOException {
List<ElfRelocation> relocations = new ArrayList<>();
if (entrySize <= 0) {
entrySize = ElfRelocation.getStandardRelocationEntrySize(elfHeader.is64Bit(), addendTypeReloc);
}
int nRelocs = (int) (length / entrySize);
for (int relocationIndex = 0; relocationIndex < nRelocs; ++relocationIndex) {
relocations.add(ElfRelocation.createElfRelocation(reader, elfHeader, relocationIndex,
@ -258,8 +261,8 @@ public class ElfRelocationTable implements ElfFileSection, ByteArrayConverter {
public byte[] toBytes(DataConverter dc) {
byte[] bytes = new byte[relocs.length * relocs[0].sizeof()];
int index = 0;
for (int i = 0; i < relocs.length; i++) {
byte[] relocBytes = relocs[i].toBytes(dc);
for (ElfRelocation reloc : relocs) {
byte[] relocBytes = reloc.toBytes(dc);
System.arraycopy(relocBytes, 0, bytes, index, relocBytes.length);
index += relocBytes.length;
}