Newer
Older
#endif
}
DisasmLocs.clear();
IDAProLocs.clear();
clc5q
committed
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
} // end of FixupIDB()
// Find and print all data head addresses in code segments.
// If an isolated code instruction is found in the midst of a run
// of data bytes and has no code xrefs jumping to it, it is not
// reachable as code and is undoubtedly a mixup by IDA. Possibly
// the whole data region will be converted to code later, in which
// case the isolated code is not necessarily properly aligned and
// parsed at its present address, so we are glad to convert it into
// data anyway so that FindDataToConvert() will succeed on it later.
// Data to code conversion, and isolated code detection, are inhibited
// by IDA identifying several consecutive instructions in the midst
// of a data region, with the code addresses not agreeing with the
// external disassembler's code addresses. We will convert these
// misaligned instructions to data as we detect them. We will also
// convert unexplored bytes (isUnknown(flags) == true) into data if
// they are in the midst of a data sequence.
#define MIN_DATARUN_LEN 24 // #bytes on either side of "isolated" code
void FindDataInCode(void) {
size_t DataRunLen = 0; // How many data bytes in a row have we seen?
bool IsolatedCodeTrigger = false; // Have seen data, then isolated code
// Now looking for data
ea_t IsolatedCodeAddr;
int IsolatedCodeLen;
int InstrLen;
clc5q
committed
bool InstOK;
insn_t LocalCmd;
ulong LocalFeatures;
clc5q
committed
for (STARS_Segment_t *seg = SMP_get_first_seg(); NULL != seg; seg = SMP_get_next_seg(RecentAddr)) {
RecentAddr = seg->get_startEA();
if (!seg->IsCodeSegment())
clc5q
committed
continue;
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
char SegName[MAXSTR];
clc5q
committed
ssize_t SegNameSize = SMP_get_segm_name(seg, SegName, sizeof(SegName) - 1);
SMP_msg("Non-code addresses for code segment %s from %x to %x\n",
clc5q
committed
SegName, seg->startEA, seg->endEA);
#endif
for (ea_t addr = seg->get_startEA(); addr < seg->get_endEA(); addr = get_item_end(addr)) {
clc5q
committed
flags_t AddrFlags = getFlags(addr);
if (isHead(AddrFlags)) {
if (isData(AddrFlags)) {
DataRunLen += get_item_size(addr);
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("Data: %x\n", addr);
clc5q
committed
#endif
if (MIN_DATARUN_LEN <= DataRunLen) {
if (IsolatedCodeTrigger) {
// Saw data, then one isolated code, then data
do_unknown_range(IsolatedCodeAddr, IsolatedCodeLen, DOUNK_SIMPLE);
RemoveIDACodeAddr(IsolatedCodeAddr);
if (do_data_ex(IsolatedCodeAddr, byteflag(),
IsolatedCodeLen, BADNODE)) {
SMP_msg("Converted isolated code to data: %lx\n",
(unsigned long) IsolatedCodeAddr);
clc5q
committed
}
else {
SMP_msg("Failed to convert isolated code to data: %lx len: %x\n",
(unsigned long) IsolatedCodeAddr, IsolatedCodeLen);
clc5q
committed
}
IsolatedCodeTrigger = false;
} // end if (IsolatedCodeTrigger)
} // end if (MIN_DATARUN_LEN <= DataRunLen)
} // end if (isData(AddrFlags)
else if (isUnknown(AddrFlags)) {
// Just in case; unknown usually means not head or tail
// If in a data run, convert to data.
InstrLen = get_item_size(addr);
clc5q
committed
SMP_msg("Unknown: %x len: %x\n", addr, InstrLen);
clc5q
committed
if (0 < DataRunLen) {
if (do_data_ex(addr, byteflag(), InstrLen, BADNODE)) {
clc5q
committed
SMP_msg("Converted unknown to data at %x len: %x\n", addr, InstrLen);
clc5q
committed
DataRunLen += InstrLen;
}
else {
clc5q
committed
SMP_msg("Failed to convert unknown to data at %x len: %x\n", addr, InstrLen);
clc5q
committed
DataRunLen = 0;
IsolatedCodeTrigger = false;
}
}
}
else if (isCode(AddrFlags)) { // must be true
if (MIN_DATARUN_LEN <= DataRunLen) {
clc5q
committed
SMP_msg("DataRunLen: %d at %x\n", DataRunLen, addr);
clc5q
committed
InstOK = SMPGetCmd(addr, LocalCmd, LocalFeatures);
assert(InstOK);
InstrLen = (int) LocalCmd.size;
// We don't check the returned InstrLen for validity because IsCodeMisaligned()
// will check for validity immediately below.
clc5q
committed
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("Calling IsCodeMisaligned: len %d\n", InstrLen);
clc5q
committed
#endif
if (IsCodeMisaligned(addr)) {
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("Code was misaligned.\n");
clc5q
committed
#endif
do_unknown_range(addr, InstrLen, DOUNK_SIMPLE);
RemoveIDACodeAddr(addr);
if (do_data_ex(addr, byteflag(), InstrLen, BADNODE)) {
clc5q
committed
SMP_msg("Converted misaligned code to data at %x : len: %x\n",
clc5q
committed
addr, InstrLen);
clc5q
committed
// Step back so data gets processed.
DataRunLen += get_item_size(addr);
continue; // skip reset of DataRunLen
}
else {
clc5q
committed
SMP_msg("Misaligned code left as unknown at %x : len: %x\n",
clc5q
committed
addr, InstrLen);
clc5q
committed
IsolatedCodeTrigger = false;
}
} // end if (IsCodeMisaligned() ...)
else if (!hasRef(AddrFlags)) {
// No references at all --> isolated code.
IsolatedCodeTrigger = true;
IsolatedCodeAddr = addr;
IsolatedCodeLen = InstrLen;
}
else {
clc5q
committed
SMP_xref_t xb;
bool ok = xb.SMP_first_to(addr, XREF_ALL);
clc5q
committed
if (!ok) {
// No code xrefs to this target addr.
IsolatedCodeTrigger = true;
IsolatedCodeAddr = addr;
IsolatedCodeLen = InstrLen;
}
}
} // end if (MIN_DATARUN_LEN <= DataRunLen)
else if (IsolatedCodeTrigger) {
// Two instructions in a row does not fit the pattern.
IsolatedCodeTrigger = false;
}
DataRunLen = 0;
} // end if (isData) ... else if (isUnknown) ... else isCode
} // end if (isHead)
else if (isUnknown(AddrFlags)) {
// If in a data run, convert to data.
InstrLen = get_item_size(addr);
clc5q
committed
SMP_msg("Unknown: %x len: %x\n", addr, InstrLen);
clc5q
committed
if (0 < DataRunLen) {
if (do_data_ex(addr, byteflag(), InstrLen, BADNODE)) {
clc5q
committed
SMP_msg("Converted unknown to data at %x len: %x\n", addr, InstrLen);
clc5q
committed
DataRunLen += InstrLen;
}
else {
clc5q
committed
SMP_msg("Failed to convert unknown to data at %x len: %x\n", addr, InstrLen);
clc5q
committed
DataRunLen = 0;
IsolatedCodeTrigger = false;
}
}
}
} // end for (ea_t addr = seg->startEA; ...)
clc5q
committed
return;
} // end of FindDataInCode()
// The choices that IDA makes for deciding which parent function of a
// TAIL chunk is the primary owner of the tail can be counterintuitive.
// A function entry can both fall into and jump to a tail chunk that
// is contiguous with it, yet the "owner" might be a function that is
// far below it in the executable address space. This function will
// change the ownership to a more sensible arrangement.
void AuditTailChunkOwnership(void) {
clc5q
committed
} // end of AuditTailChunkOwnership()
// If the addresses signified from DisasmIndex to IDAProIndex are
// all considered data and do NOT follow a return instruction,
// return false and update AreaSize to reflect the area to be
// converted.
// Return value: true -> skip to IDAProIndex; false -> convert AreaSize bytes.
bool FindDataToConvert(size_t IDAProIndex, size_t DisasmIndex, int &AreaSize) {
ea_t PrevIDAAddr;
ea_t NextIDAAddr;
size_t ShadowDisasmIndex = DisasmIndex - 1;
ea_t DisasmAddr = DisasmLocs[ShadowDisasmIndex];
bool CannotConvert = false; // return value
bool DebugAddress = false;
#if SMP_DEBUG_FIXUP_IDB
DebugAddress = (DisasmAddr == 0x806c19a);
#endif
if (DebugAddress) {
clc5q
committed
SMP_msg("IDAProIndex: %zu DisasmIndex: %zu\n", IDAProIndex, DisasmIndex);
SMP_msg("IDA locs size %zu Disasm locs size %zu\n", IDAProLocs.size(),
clc5q
committed
DisasmLocs.size());
}
if (IDAProIndex >= IDAProLocs.size()) {
// Have already processed the last IDA address.
clc5q
committed
if (DebugAddress) SMP_msg(" Already done with IDAProLocs.\n");
clc5q
committed
return true;
}
else if (DisasmIndex >= DisasmLocs.size()) {
// Strange. Last Disasm address is only one to convert, and
// IDA still has addresses after that?
clc5q
committed
if (DebugAddress) SMP_msg(" Already done with DisasmLocs.\n");
clc5q
committed
return true;
}
else if (IDAProIndex < 2) {
// We have Disasm addrs before the very first IDA addr. We
// don't trust this boundary case.
clc5q
committed
if (DebugAddress) SMP_msg(" Boundary case with IDAProLocs.\n");
clc5q
committed
return true;
}
NextIDAAddr = IDAProLocs[IDAProIndex - 1];
PrevIDAAddr = IDAProLocs[IDAProIndex - 2];
if (DebugAddress) SMP_msg(" PrevIDAAddr: %lx NextIDAAddr: %lx\n", (unsigned long) PrevIDAAddr, (unsigned long) NextIDAAddr);
clc5q
committed
// See if previous IDA address was a return.
flags_t PrevFlags = getFlags(PrevIDAAddr);
if (!isCode(PrevFlags) || !isHead(PrevFlags)) {
SMP_msg("PrevIDAAddr %lx not isCode or not isHead.\n", (unsigned long) PrevIDAAddr);
clc5q
committed
return true;
}
SMPInstr PrevInstr(PrevIDAAddr);
PrevInstr.Analyze();
clc5q
committed
if (DebugAddress) SMP_msg("Finished PrevInstr.Analyze()\n");
clc5q
committed
if (PrevInstr.MDIsReturnInstr()) {
// Right after a return come no-ops and 2-byte no-ops
// that are just for alignment. IDA does not seem to be
// happy when we convert all those to code.
clc5q
committed
if (DebugAddress) SMP_msg(" Data followed a return instruction.\n");
clc5q
committed
return true;
}
// Now, see if the area from DisasmAddr to NextIDAAddr is all data
// according to IDA.
while (DisasmAddr < NextIDAAddr) {
flags_t DataFlags = getFlags(DisasmAddr);
if (isTail(DataFlags)) {
if (DebugAddress) SMP_msg(" tail byte: %lx\n", (unsigned long) DisasmAddr);
clc5q
committed
DisasmAddr = get_item_end(DisasmAddr);
}
else if (isData(DataFlags)) {
if (DebugAddress) SMP_msg(" data byte: %lx\n", (unsigned long) DisasmAddr);
clc5q
committed
DisasmAddr = get_item_end(DisasmAddr);
}
else if (isCode(DataFlags)) {
// How could this ever happen?
if (DebugAddress) SMP_msg(" isCode: %lx\n", (unsigned long) DisasmAddr);
clc5q
committed
return true;
}
else { // must be isUnknown()
// Very conservative here; only want to convert when the whole
// region is data, because that is a symptom of IDA missing
// a piece of code within a function (usually a piece of code
// that is only reachable via an indirect jump).
if (DebugAddress) SMP_msg(" Not isData: %lx\n", (unsigned long) DisasmAddr);
clc5q
committed
return true;
}
if (DebugAddress) SMP_msg(" new DisasmAddr: %lx\n", (unsigned long) DisasmAddr);
clc5q
committed
} // end while (DisasmAddr < NextIDAAddr)
clc5q
committed
if (DebugAddress) SMP_msg(" loop exit CannotConvert: %d\n", CannotConvert);
clc5q
committed
if (!CannotConvert) {
// Success.
DisasmAddr = DisasmLocs[ShadowDisasmIndex];
AreaSize = NextIDAAddr - DisasmAddr;
if (DebugAddress) {
clc5q
committed
SMP_msg(" Success! AreaSize: %x Old index: %zu new index: %zu\n",
clc5q
committed
AreaSize, ShadowDisasmIndex, DisasmIndex);
clc5q
committed
SMP_msg(" exiting FindDataToConvert()\n");
SMP_msg("\n");
clc5q
committed
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
}
} // end if (!CannotConvert)
return CannotConvert;
} // end of FindDataToConvert()
// Does a converted code region look like a function prologue? If so,
// we should not include it in the previous function.
bool IsFunctionPrologue(ea_t StartAddr, ea_t EndAddr) {
return false; // **!!** TODO
} // end of IsFunctionPrologue()
// Patch program bytes that could not be converted from
// data to code, if it can be determined that the bytes represent code
// that IDA has a hard time with.
// Currently limited to finding "call near ptr 0" instructions, which
// often are found in optimized glibc code because gcc was able to
// determine that a function pointer was zero and did constant propagation,
// but unfortunately was not able to determine that the code was unreachable.
// IDA will not succeed in ua_code() for "call 0", but there is no danger
// of a working program ever executing this code. Replacing the call with
// no-ops permits us to continue converting a contiguous range of data to
// code, and permits IDA to reanalyze the function later.
// Returns true if program bytes were patched.
bool MDPatchUnconvertedBytes(ea_t CurrDisasmAddr) {
flags_t AddrFlags = getFlags(CurrDisasmAddr);
if (isData(AddrFlags) || isTail(AddrFlags)) {
// Bytes should have been converted to unknown already.
clc5q
committed
SMP_msg("Cannot patch data bytes or tail bytes at %x\n", CurrDisasmAddr);
clc5q
committed
return false;
}
SMPInstr PatchInstr(CurrDisasmAddr);
PatchInstr.Analyze();
int InstrLen = PatchInstr.GetCmd().size;
if (0 >= InstrLen) {
clc5q
committed
SMP_msg("decode_insn() failed on patch location %x\n", CurrDisasmAddr);
clc5q
committed
return false;
}
else {
if (PatchInstr.GetCmd().itype != NN_call) {
clc5q
committed
SMP_msg("Cannot patch non-call instruction at %x\n", CurrDisasmAddr);
clc5q
committed
return false;
}
PatchInstr.PrintOperands();
op_t CallDest = PatchInstr.GetFirstUse()->GetOp();
clc5q
committed
if ((o_near != CallDest.type) || (0 != CallDest.addr)) {
clc5q
committed
SMP_msg("Cannot patch call unless it is call near ptr 0 at %x",
clc5q
committed
CurrDisasmAddr);
clc5q
committed
return false;
}
ea_t PatchAddr = CurrDisasmAddr;
for (int i = 0; i < InstrLen; ++i) {
bool ok = patch_byte(PatchAddr, 0x90); // x86 no-op
if (!ok) {
clc5q
committed
SMP_msg("patch_byte() failed at %x\n", PatchAddr);
clc5q
committed
return false;
}
++PatchAddr;
}
clc5q
committed
SMP_msg("Patched %d bytes successfully at %x\n", InstrLen, CurrDisasmAddr);
#if IDA_SDK_VERSION < 600
InstrLen = ua_code(CurrDisasmAddr);
#else
InstrLen = create_insn(CurrDisasmAddr);
clc5q
committed
if (0 >= InstrLen) {
clc5q
committed
SMP_msg(" ... but ua_code() still failed!\n");
clc5q
committed
return false;
}
} // end if (0 >= InstrLen) ... else ...
return true;
} // end of MDPatchUnconvertedBytes()
// Use the lists of code addresses identified by IDA Pro (in IDAProLocs)
clc5q
committed
// and an external disassembler (in DisasmLocs). Compare the lists and
// try to convert addresses to code that are found in DisasmLocs but
// not in IDAProLocs. Emit warnings when IDAProLocs has a code address
// not found in DisasmLocs.
void FixCodeIdentification(void) {
size_t DisasmIndex = 0;
ea_t CurrDisasmAddr = DisasmLocs[DisasmIndex++];
size_t IDAProIndex = 0;
ea_t CurrAddr = IDAProLocs[IDAProIndex++];
while (DisasmIndex <= DisasmLocs.size()) {
// If the current address is less than the current
// external disasm address, we have the rare case in
// which IDA Pro has identified an address as code
// but the external disasm has not. Emit a warning
// message and go on to the next IDA address.
if (CurrAddr < CurrDisasmAddr) {
SMPInstr TempInstr(CurrAddr);
TempInstr.Analyze();
SMP_msg("AUDIT: Address %lx is code in IDB but not in external disassembler: %s\n",
(unsigned long) CurrAddr, TempInstr.GetDisasm());
clc5q
committed
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
if (IDAProIndex < IDAProLocs.size())
CurrAddr = IDAProLocs[IDAProIndex++];
else {
// Last IDA addr; might still process Disasm addrs
// after loop exit.
break;
}
}
else if (CurrAddr == CurrDisasmAddr) {
// If equal, no problem, we are moving through the
// code addresses in lockstep. Grab the next address
// from each source.
if (DisasmIndex < DisasmLocs.size()) {
CurrDisasmAddr = DisasmLocs[DisasmIndex++];
}
else {
++DisasmIndex; // cause loop exit; skip cleanup loop
}
if (IDAProIndex < IDAProLocs.size())
CurrAddr = IDAProLocs[IDAProIndex++];
else {
// Last IDA addr; might still process Disasm addrs
// after loop exit in cleanup loop.
break;
}
}
else {
// We must have CurrAddr > CurrDisasmAddr. That means
// IDA has jumped over some code addresses in
// DisasmLocs. We need to try to convert addresses
// to code until we can reach the current addr.
// For now, we will address only the case in which IDA
// has identified addresses as data bytes, and the
// external disassembler(e.g. objdump) has identified
// the same addresses as code. We only want to deal with
// contiguous areas of data-to-code conversion that do NOT
// follow a return statement.
int AreaSize = 0;
ea_t AreaStart = CurrDisasmAddr;
ea_t AreaEnd;
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("CurrDisasmAddr: %x CurrAddr: %x\n", CurrDisasmAddr, CurrAddr);
clc5q
committed
#endif
bool SkipArea = FindDataToConvert(IDAProIndex, DisasmIndex, AreaSize);
if (SkipArea) {
// Skip over the extra external disasm addresses.
while (CurrDisasmAddr < CurrAddr)
CurrDisasmAddr = DisasmLocs[DisasmIndex++];
}
else {
// Convert the overlooked code region to unexplored.
AreaEnd = CurrDisasmAddr + AreaSize;
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("Found data to convert: %x to %x\n", AreaStart, AreaEnd);
clc5q
committed
#endif
do_unknown_range(AreaStart, AreaSize, DOUNK_SIMPLE);
SMP_bounds_t ConvertRegion;
ConvertRegion.startEA = AreaStart;
ConvertRegion.endEA = AreaEnd;
FixupRegion CurrRegion(ConvertRegion);
CodeReanalyzeList.push_back(CurrRegion);
clc5q
committed
bool AllConverted = true;
bool AllNops = true;
clc5q
committed
do {
flags_t InstrFlags = getFlags(CurrDisasmAddr);
if (!isUnknown(InstrFlags)) {
SMP_msg("Sync problem in FixCodeID: %lx\n", (unsigned long) CurrDisasmAddr);
clc5q
committed
}
else {
int InstrLen = ua_code(CurrDisasmAddr);
int InstrLen = create_insn(CurrDisasmAddr);
clc5q
committed
if (InstrLen > 0) { // Successfully converted to code
SMPInstr NewInstr(CurrDisasmAddr);
NewInstr.Analyze();
if (!NewInstr.IsNop())
AllNops = false;
clc5q
committed
#if SMP_DEBUG_FIXUP_IDB
#if 0
clc5q
committed
SMP_msg("FixCodeID success at %x: len: %d %s\n", CurrDisasmAddr,
clc5q
committed
InstrLen, NewInstr.GetDisasm());
#endif
clc5q
committed
#endif
}
else {
if (MDPatchUnconvertedBytes(CurrDisasmAddr)) {
clc5q
committed
SMP_msg(" Patched bytes at %x\n", CurrDisasmAddr);
clc5q
committed
}
else {
CurrRegion.FixupInstrs.push_back(CurrDisasmAddr);
clc5q
committed
AllConverted = false;
clc5q
committed
SMP_msg("FixCodeID failure at %x\n", CurrDisasmAddr);
clc5q
committed
}
}
} // end if (isCode(InstrFlags) ... else ...
if (DisasmIndex < DisasmLocs.size()) {
CurrDisasmAddr = DisasmLocs[DisasmIndex++];
}
else {
// cause loops to exit
CurrDisasmAddr = CurrAddr;
++DisasmIndex; // skip cleanup loop
}
} while (CurrDisasmAddr < CurrAddr);
if (AllConverted && AllNops) {
// We want to convert the region back to unexplored bytes
// and take it off the work list. Regions that are all nops
// create data flow analysis problems sometimes. The region
// is often unreachable code and produces a basic block with
// no predecessors within a function. This often happens when
// an optimizing compiler uses nops as padding to align jump
// targets on cache line bounaries. With no fall through into
// the nops, they are unreachable and should be left as unknown.
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("FixCodeID nops region from %x to %x\n", CurrRegion.GetStart(),
CurrRegion.GetEnd());
do_unknown_range(CurrRegion.GetStart(),
CurrRegion.GetEnd() - CurrRegion.GetStart(), DOUNK_SIMPLE);
CodeReanalyzeList.pop_back();
}
clc5q
committed
} // end if (SkipArea) ... else ...
} // end if (addr < CurrDisasmAddr) .. else if ... else ...
} // end while (DisasmIndex <= DisasmLocs.size()
#if 0 // Make this code use FindDataToConvert() **!!**
// Cleanup loop:
// If there are still Disasm addrs to process, try to turn them
// into code in the IDB.
while (DisasmIndex <= DisasmLocs.size()) {
flags_t InstrFlags = getFlags(CurrDisasmAddr);
if (isCode(InstrFlags)) {
clc5q
committed
SMP_msg("Sync problem in FixCodeID: %x\n", CurrDisasmAddr);
clc5q
committed
}
else {
// Clear bytes to unexplored.
clc5q
committed
segment_t *seg = SMP_getseg(CurrDisasmAddr);
clc5q
committed
if (SEG_CODE == seg->type) {
do_unknown_range(CurrDisasmAddr, seg->endEA - CurrDisasmAddr, DOUNK_SIMPLE);
}
else {
// Might be safest to just discontinue processing
// if we wander into a non-code segment.
// DisasmLocs should not have an entire code segment
// that IDA Pro missed.
break;
}
int InstrLen = ua_code(CurrDisasmAddr);
if (InstrLen > 0) { // Successfully converted to code
SMPInstr NewInstr(CurrDisasmAddr);
NewInstr.Analyze();
clc5q
committed
SMP_msg("FixCodeID success at %x: %s\n", CurrDisasmAddr,
clc5q
committed
NewInstr.GetDisasm());
}
else {
clc5q
committed
SMP_msg("FixCodeID failure at %x\n", CurrDisasmAddr);
clc5q
committed
}
} // end if (isCode(InstrFlags) ... else ...
if (DisasmIndex < DisasmLocs.size()) {
CurrDisasmAddr = DisasmLocs[DisasmIndex++];
}
else {
++DisasmIndex; // cause loop to exit
}
} // end while (DisasmIndex <= DisasmLocs.size()
#endif
return;
} // end of FixCodeIdentification()
// Analyze instructions that could not be analyzed earlier and were placed on the CodeReanalyzeList.
// Earlier failures are usually because the instruction branches to an address that has not
// yet been converted from data to code, so ua_code() failed. Now that all data to code
// conversions have completed, ua_code() should succeed.
// Return the number of instructions successfully analyzed.
int FixupNewCodeChunks(void) {
list<FixupRegion>::iterator CurrRegion;
int changes = 0;
for (CurrRegion = CodeReanalyzeList.begin(); CurrRegion != CodeReanalyzeList.end(); ++CurrRegion) {
bool AllConverted = true;
bool AllNops = true;
bool NoFixups = (0 == CurrRegion->FixupInstrs.size());
if (NoFixups) {
CurrRegion->SetStart(BADADDR); // mark for removal
continue; // skip to next region
}
list<ea_t>::iterator CurrInstr;
for (CurrInstr = CurrRegion->FixupInstrs.begin(); CurrInstr != CurrRegion->FixupInstrs.end(); ++CurrInstr) {
#if IDA_SDK_VERSION < 600
int InstrLen = ua_code(*CurrInstr);
#else
int InstrLen = create_insn(*CurrInstr);
if (InstrLen > 0) { // Successfully converted to code
SMPInstr NewInstr(*CurrInstr);
NewInstr.Analyze();
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("FixupNewCodeChunks success at %x: len: %d\n", *CurrInstr, InstrLen);
#endif
if (!NewInstr.IsNop()) {
AllNops = false;
*CurrInstr = BADADDR; // mark for removal
}
}
else {
AllConverted = false;
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("FixupNewCodeChunks failure at %x\n", *CurrInstr);
#endif
}
} // end for all instrs in CurrRegion
if (AllConverted && !AllNops) {
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("FixupNewCodeChunks success for region from %x to %x\n",
CurrRegion->GetStart(), CurrRegion->GetEnd());
#endif
CurrRegion->SetStart(BADADDR); // mark for removal
}
else if (AllConverted && AllNops) {
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg("FixupNewCodeChunks re-converting nops region from %x to %x\n",
CurrRegion->GetStart(), CurrRegion->GetEnd());
#endif
do_unknown_range(CurrRegion->GetStart(),
CurrRegion->GetEnd() - CurrRegion->GetStart(), DOUNK_SIMPLE);
CurrRegion->SetStart(BADADDR); // mark for removal
}
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
else {
// Remove only the instructions that were fixed up.
CurrInstr = CurrRegion->FixupInstrs.begin();
while (CurrInstr != CurrRegion->FixupInstrs.end()) {
if (BADADDR == *CurrInstr) {
CurrInstr = CurrRegion->FixupInstrs.erase(CurrInstr);
}
else {
++CurrInstr;
}
}
}
} // end for all regions in the CodeReanalyzeList
// Remove completed regions from the CodeReanalyzeList
CurrRegion = CodeReanalyzeList.begin();
while (CurrRegion != CodeReanalyzeList.end()) {
if (BADADDR == CurrRegion->GetStart())
CurrRegion = CodeReanalyzeList.erase(CurrRegion);
else
++CurrRegion;
}
#if 0
if (AllConverted) {
if (IsFunctionPrologue(AreaStart, AreaEnd)) {
// Create a new function entry chunk here.
// **!!** TODO
;
}
else {
// Extend the previous chunk to include the
// converted code.
ea_t PrevIDAAddr = IDAProLocs[IDAProIndex - 2];
STARS_Function_t *PrevChunk = get_fchunk(PrevIDAAddr);
#if SMP_DEBUG_FIXUP_IDB
clc5q
committed
SMP_msg(" addr in chunk to extend: %x\n", PrevIDAAddr);
SMP_msg(" STARS_Function_t pointer for chunk: %x\n", PrevChunk);
#endif
#if 0 // temporary for debugging
if (is_func_entry(PrevChunk)) {
// Extend the func entry to contain the new code.
if (func_setend(PrevIDAAddr, AreaEnd)) {
clc5q
committed
SMP_msg("Func extended to include code from %x to %x\n",
AreaStart, AreaEnd);
FuncReanalyzeList.push_back(PrevIDAAddr);
}
else {
clc5q
committed
SMP_msg("Failed to extend func from %x to %x\n",
AreaStart, AreaEnd);
}
}
else { // tail
// See if this works for function tails, also.
// Extend the func entry to contain the new code.
if (func_setend(PrevIDAAddr, AreaEnd)) {
clc5q
committed
SMP_msg("Tail extended to include code from %x to %x\n",
AreaStart, AreaEnd);
STARS_Function_t *TailOwner = get_func(PrevChunk->owner);
FuncReanalyzeList.push_back(PrevIDAAddr);
}
else {
clc5q
committed
SMP_msg("Failed to extend tail from %x to %x\n",
AreaStart, AreaEnd);
}
} // end if (is_func_entry()) ... else ...
#endif
} // end if (IsFunctionPrologue()) ... else ...
} // end if (AllConverted)
else {
clc5q
committed
SMP_msg("not AllConverted; cannot include new code in previous chunk.\n");
}
#endif
return changes;
} // end of FixupNewCodeChunnks()
// Audit the IDA code database by looking at all instructions in the
// code segment and printing all those that are not contained in a
// function. Emit the context-free annotations that we are able to
// emit on a per-instruction basis.
void FindOrphanedCode(STARS_Segment_t *CurrSeg, FILE *AnnotFile, FILE *InfoAnnotFile) {
for (ea_t addr = CurrSeg->get_startEA(); addr < CurrSeg->get_endEA();
flags_t InstrFlags = getFlags(addr);
clc5q
committed
if (isTail(InstrFlags))
continue;
if (isHead(InstrFlags) && isCode(InstrFlags)) {
ea_t FirstFuncAddr;
if (!(CurrProg->IsInstAddrStillInFunction(addr, FirstFuncAddr))) {
SMPInstr CurrInst(addr);
CurrInst.Analyze();
clc5q
committed
SMP_msg("Orphan code at %x : %s\n", addr, CurrInst.GetDisasm());
// TODO: If there are code xrefs to the orphan code,
// see what kind. If a CALL, and orphan code looks
// like a prologue, make a function. If a JUMP of
// some kind, then make a function chunk and make
// it a tail of all functions that jump to it. **!!**
clc5q
committed
// Do machine-dependent fixes for DEF and USE lists.
// The fixes can help produce better annotations.
CurrInst.MDFixupDefUseLists();
// If instruction is still not included in a code chunk,
// emit annotations for it in isolation.
CurrInst.EmitAnnotations(true, false, true, AnnotFile, InfoAnnotFile, CurrProg);
// If instruction is an indirect branch, emit an XREF
// annotation for each of its targets.
SMPitype CurrDataFlow = CurrInst.GetDataFlowType();
if ((CurrDataFlow == INDIR_JUMP) || (CurrDataFlow == INDIR_CALL)) {
SMP_xref_t xrefs;
for (bool ok = xrefs.SMP_first_from(addr, XREF_ALL); ok; ok = xrefs.SMP_next_from()) {
if (xrefs.GetTo() != 0) {
if (xrefs.GetIscode() && (xrefs.GetType() != fl_F)) {
// Found a code target, with its address in xrefs.to
PrintCodeToCodeXref(addr, xrefs.GetTo(), CurrInst.GetSize());
}
}
}
}
}
}
else if (isUnknown(InstrFlags)) {
clc5q
committed
SMP_msg("Unanalyzed byte at %x\n", addr);
// Can IDA analyze this to be code?
int InstrLen;
#if IDA_SDK_VERSION < 600
InstrLen = ua_code(addr);
#else
InstrLen = create_insn(addr);
#endif
bool IDAsuccess = generate_disasm_line(addr, disasm, sizeof(disasm) - 1);
if (IDAsuccess) {
// Remove interactive color-coding tags.
ssize_t StringLen = tag_remove(disasm, disasm, 0);
if (-1 >= StringLen) {
SMP_msg("ERROR: tag_remove failed at addr %lx \n", (unsigned long) addr);
clc5q
committed
SMP_msg("Successfully analyzed! %s\n", disasm);
SMPInstr UnknownInstr(addr);
UnknownInstr.Analyze();
// TODO: Get new code into a chunk. **!!**
// If instruction is still not included in a code chunk,
// emit annotations for it in isolation.
UnknownInstr.EmitAnnotations(true, false, true, AnnotFile, InfoAnnotFile, CurrProg);
SMP_msg("ERROR: generate_disasm_line failed at addr %lx \n", (unsigned long) addr);
}
}
} // end for (ea_t addr = CurrSeg->startEA; ...)
} // end of FindOrphanedCode()
// Version of FindOrphanedCode that does not emit annotations but can be used
// to determine at what point in time code becomes orphaned.
void Debug_FindOrphanedCode(STARS_Segment_t *CurrSeg, bool FirstRun) {
ea_t DebugAddr = 0x8050db0;
for (ea_t addr = CurrSeg->get_startEA(); addr < CurrSeg->get_endEA();
addr = get_item_end(addr)) {
flags_t InstrFlags = getFlags(addr);
if (isHead(InstrFlags) && isCode(InstrFlags)) {
STARS_Function_t *CurrFunc = SMP_get_func(addr);
if (NULL == CurrFunc) { // Code not in a func; orphaned
pair<set<ea_t>::iterator, bool> pairib;
pairib = CodeOrphans.insert(addr);
if (DebugAddr == addr) {
SMP_msg("DEBUG: Orphaned code addr %lx found.\n", (unsigned long) addr);
}
if ((!FirstRun) && (pairib.second)) {
SMP_msg("SERIOUS WARNING: Newly orphaned code at %lx \n", (unsigned long) addr);
}
}
}
} // end for (ea_t addr = CurrSeg->startEA; ...)
} // end of Debug_FindOrphanedCode()
// Audit the IDA database with respect to branches and calls. They should
// each have valid code targets (not data or unknown bytes) and the code
// cross references should reflect the linkage.
void AuditCodeTargets(void) {
} // end of AuditCodeTargets()
void SpecialDebugOutput(void) {
char disasm[MAXSTR];
vector<ea_t> ProblemAddrs;
ProblemAddrs.push_back(0x8066d08);
bool IDAsuccess;
int InstLen;
ssize_t StringLen;
clc5q
committed
insn_t LocalCmd;
ulong LocalFeatures;
for (size_t index = 0; index < ProblemAddrs.size(); ++index) {
ea_t addr = ProblemAddrs[index];
flags_t InstrFlags = getFlags(addr);
if (isCode(InstrFlags) && isHead(InstrFlags)) {
clc5q
committed
IDAsuccess = SMPGetCmd(addr, LocalCmd, LocalFeatures);
InstLen = (int) LocalCmd.size;
if ((IDAsuccess) && (0 < InstLen)) {
IDAsuccess = generate_disasm_line(addr, disasm, sizeof(disasm) - 1);
if (IDAsuccess) {
StringLen = tag_remove(disasm, disasm, 0);
if (-1 < StringLen)
SMP_msg("Problem addr %lx : %s\n", (unsigned long) addr, disasm);
SMP_msg("ERROR: tag_remove failed at addr %lx \n", (unsigned long) addr);
SMP_msg("ERROR: generate_disasm_line failed at addr %lx \n", (unsigned long) addr);
SMP_msg("ERROR: decode_insn failed at addr %lx \n", (unsigned long) addr);
}
}
return;
} // end of SpecialDebugOutput()
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
// Convert a call type string from the policy file, such as "FILECALLS", to the
// corresponding ZST_SysCallType, such as ZST_FILE_CALL.
ZST_SysCallType ConvertStringToCallType(char *Str2) {
ZST_SysCallType ReturnVal;
if (0 == strcmp("PRIVILEGECALLS", Str2)) {
ReturnVal = ZST_HIGHPRIVILEGE_CALL;
}
else if (0 == strcmp("FILECALLS", Str2)) {
ReturnVal = ZST_FILE_CALL;
}
else if (0 == strcmp("NETWORKCALLS", Str2)) {
ReturnVal = ZST_NETWORK_CALL;
}
else {
ReturnVal = ZST_UNMONITORED_CALL;
}
return ReturnVal;
} // end of ConvertStringToCallType()
// Convert a policy string from the policy file, such as "DISALLOW", to
// the corresponding ZST_Policy value, such as ZST_DISALLOW.
ZST_Policy ConvertStringToPolicy(char *Str3) {
ZST_Policy ReturnVal;
if (0 == strcmp("DISALLOW", Str3)) {
ReturnVal = ZST_DISALLOW;
}
else if (0 == strcmp("WHITELIST", Str3)) {
ReturnVal = ZST_WHITELIST;
}
else if (0 == strcmp("BLACKLIST", Str3)) {
ReturnVal = ZST_BLACKLIST;
}
else { // error handling precedes calls to this function
ReturnVal = ZST_ALLOWALL;
}
return ReturnVal;
} // end of ConvertStringToPolicy()
// Given a function name, return its Zephyr Security Toolkit call type.
ZST_SysCallType GetCallTypeFromFuncName(string SysCallName) {
ZST_SysCallType ReturnVal;
map<string, ZST_SysCallType>::iterator FindIter = ZST_FuncTypeMap.find(SysCallName);
if (FindIter == ZST_FuncTypeMap.end()) { // not found; might not even be system call
ReturnVal = ZST_UNMONITORED_CALL;
}
else {
ReturnVal = FindIter->second;
}
return ReturnVal;
} // end of GetCallTypeFromFuncName()
// Get the user-specified security policy for the given call type.
ZST_Policy GetPolicyFromCallType(ZST_SysCallType CallType) {
ZST_Policy ReturnVal;
map<ZST_SysCallType, ZST_Policy>::iterator FindIter = ZST_TypePolicyMap.find(CallType);
if (FindIter == ZST_TypePolicyMap.end()) {
// Policy not found; default to ALLOW_ALL
ReturnVal = ZST_ALLOWALL;
}
else {
ReturnVal = FindIter->second;
}
return ReturnVal;
} // end of GetPolicyFromCallType()
// Given a call type and called function name, is it on the location whitelist
// for that call type?
// NOTE: HANDLE CASE IN WHICH WHITELISTED LOCATION IS A PREFIX, TERMINATING in a slash.
bool IsLocationWhitelisted(ZST_SysCallType CallType, string LocationName) {
set<string>::iterator FindIter;
bool ReturnVal;
if (CallType == ZST_FILE_CALL) {
FindIter = ZST_FileLocWhitelist.find(LocationName);
ReturnVal = (FindIter != ZST_FileLocWhitelist.end());
}
else if (CallType == ZST_NETWORK_CALL) {
FindIter = ZST_NetworkLocWhitelist.find(LocationName);
ReturnVal = (FindIter != ZST_NetworkLocWhitelist.end());
}
else { // should not be here
ReturnVal = false;
}
return ReturnVal;
} // end of IsLocationWhitelisted()
// Given a call type and called function name, is it on the location blacklist
// for that call type?
// NOTE: HANDLE CASE IN WHICH BLACKLISTED LOCATION IS A PREFIX, TERMINATING in a slash.
bool IsLocationBlacklisted(ZST_SysCallType CallType, string LocationName) {
set<string>::iterator FindIter;
bool ReturnVal;
if (CallType == ZST_FILE_CALL) {
FindIter = ZST_FileLocBlacklist.find(LocationName);
ReturnVal = (FindIter != ZST_FileLocBlacklist.end());
}
else if (CallType == ZST_NETWORK_CALL) {
FindIter = ZST_NetworkLocBlacklist.find(LocationName);
ReturnVal = (FindIter != ZST_NetworkLocBlacklist.end());
}
else { // should not be here
ReturnVal = false;
}
return ReturnVal;
}
// Given a called function name, does it produce only benign numeric errors when
// its returned values are used in arithmetic? (i.e. it is a trusted input)
bool IsNumericSafeSystemCall(string CallName) {
set<string>::iterator FindIter = ZST_SystemCallNumericWhitelist.find(CallName);
bool ReturnVal = (FindIter != ZST_SystemCallNumericWhitelist.end());
return ReturnVal;
}
// Utility functions to print code xrefs to STARS_XrefsFile
void PrintCodeToCodeXref(ea_t FromAddr, ea_t ToAddr, size_t InstrSize) {
SMP_fprintf(STARS_XrefsFile, "%10lx %6zu INSTR XREF IBT FROMIB %10lx \n",
(unsigned long) ToAddr, InstrSize, (unsigned long) FromAddr);
return;
}
void PrintDataToCodeXref(ea_t FromDataAddr, ea_t ToCodeAddr, size_t InstrSize) {
SMP_fprintf(STARS_XrefsFile, "%10lx %6zu INSTR XREF IBT FROMDATA %10lx \n",
(unsigned long) ToCodeAddr, InstrSize, (unsigned long) FromDataAddr);
return;
}
// These two constants should agree with their counterparts in ZST-policy.c.
#define ZST_MAX_FILE_NAME_LEN 1024
#define ZST_MAX_CALL_NAME_LEN 64