/** Returns a list of parts of a single section that have been referenced. The offsets are relative to the start of the
* section. */
AddressIntervalSet
SgAsmGenericSection::get_referenced_extents() const
{
if (0==get_size())
return AddressIntervalSet();
AddressIntervalSet retval;
AddressInterval segment = AddressInterval::baseSize(get_offset(), get_size());
const AddressIntervalSet &fileExtents = get_file()->get_referenced_extents();
BOOST_FOREACH (const AddressInterval &interval, fileExtents.intervals()) {
if (segment.isContaining(interval)) {
retval.insert(AddressInterval::baseSize(interval.least()-get_offset(), interval.size()));
} else if (interval.isLeftOf(segment) || interval.isRightOf(segment)) {
// no overlap
} else if (interval.isContaining(segment)) {
retval.insert(AddressInterval::baseSize(0, get_size()));
break; // no point in continuing since we've referenced whole segment now
} else if (interval.least() < segment.least()) {
retval.insert(AddressInterval::baseSize(0, interval.least()+interval.size()-get_offset()));
} else if (interval.greatest() > segment.greatest()) {
retval.insert(AddressInterval::baseSize(interval.least()-get_offset(), get_offset()+get_size()-interval.least()));
} else {
ASSERT_not_reachable("invalid extent overlap category");
}
}
return retval;
}
void
MemoryMap::eraseZeros(size_t minsize)
{
if (isEmpty())
return;
unsigned permissions = READABLE | EXECUTABLE; // access permissions that must be present
AddressIntervalSet toRemove; // to save up intervals until we're done iterating
AddressInterval zeroInterval;
uint8_t buf[8192];
rose_addr_t va = hull().least();
while (AddressInterval accessed = atOrAfter(va).require(permissions).limit(sizeof buf).read(buf)) {
for (size_t offset=0; offset<accessed.size(); ++offset) {
if (0 == buf[offset]) {
if (zeroInterval.isEmpty()) {
zeroInterval = AddressInterval(accessed.least()+offset);
} else if (zeroInterval.greatest()+1 < offset) {
if (zeroInterval.size() >= minsize)
toRemove.insert(zeroInterval);
zeroInterval = AddressInterval(accessed.least()+offset);
} else {
zeroInterval = AddressInterval::hull(zeroInterval.least(), zeroInterval.greatest()+1);
}
} else if (!zeroInterval.isEmpty()) {
if (zeroInterval.size() >= minsize)
toRemove.insert(zeroInterval);
zeroInterval = AddressInterval();
}
}
if (accessed.greatest() == hull().greatest())
break; // prevent overflow in next statement
va += accessed.size();
}
if (zeroInterval.size() >= minsize)
toRemove.insert(zeroInterval);
BOOST_FOREACH (const AddressInterval &interval, toRemove.intervals())
erase(interval);
}
/** Obtains the virtual address of the Hint/Name Table. The Hint/Name Table is an implicit table--the PE file format
* specification talks about such a table, but it is not actually defined anywhere in the PE file. Instead, various Import
* Lookup Table and Import Address Table entries might point to individual Hint/Name pairs, which collectively form an
* implicit Hint/Name Table. There is no requirement that the Hint/Name pairs are contiguous in the address space, and indeed
* they often are not. Therefore, the only way to describe the location of the Hint/Name Table is by a list of addresses.
*
* This function will scan this Import Directory's import items, observe which items make references to Hint/Name pairs that
* have known addresses, and add those areas of virtual memory to the specified extent map. This function returns the number
* of ILT entries that reference a Hint/Name pair. */
size_t
SgAsmPEImportDirectory::hintname_table_extent(AddressIntervalSet &extent/*in,out*/) const
{
size_t retval = 0;
const SgAsmPEImportItemPtrList &imports = get_imports()->get_vector();
for (SgAsmPEImportItemPtrList::const_iterator ii=imports.begin(); ii!=imports.end(); ++ii) {
SgAsmPEImportItem *import = *ii;
if (!import->get_by_ordinal() && import->get_hintname_rva().get_rva()!=0 && import->get_hintname_nalloc()>0) {
size_t nbytes = std::min(import->get_hintname_nalloc(), import->hintname_required_size());
extent.insert(AddressInterval::baseSize(import->get_hintname_rva().get_va(), nbytes));
++retval;
}
}
return retval;
}
AddressIntervalSet toAddressIntervalSet(const ExtentMap &x) {
AddressIntervalSet retval;
for (ExtentMap::const_iterator iter=x.begin(); iter!=x.end(); ++iter)
retval.insert(toAddressInterval(iter->first));
return retval;
}
