void BottomOfStackStepperImpl::initialize()
{
ProcessState *proc = walker->getProcessState();
assert(proc);
sw_printf("[%s:%u] - Initializing BottomOfStackStepper\n", FILE__, __LINE__);
LibraryState *libs = proc->getLibraryTracker();
if (!libs) {
sw_printf("[%s:%u] - Error initing StackBottom. No library state for process.\n",
FILE__, __LINE__);
return;
}
SymbolReaderFactory *fact = Walker::getSymbolReader();
if (!fact) {
sw_printf("[%s:%u] - Failed to get symbol reader\n");
return;
}
if (!aout_init)
{
LibAddrPair aout_addr;
SymReader *aout = NULL;
Symbol_t start_sym;
bool result = libs->getAOut(aout_addr);
if (result) {
aout = fact->openSymbolReader(aout_addr.first);
aout_init = true;
}
if (aout) {
start_sym = aout->getSymbolByName(START_FUNC_NAME);
if (aout->isValidSymbol(start_sym)) {
Dyninst::Address start = aout->getSymbolOffset(start_sym)+aout_addr.second;
Dyninst::Address end = aout->getSymbolSize(start_sym) + start;
if (start == end) {
sw_printf("[%s:%u] - %s symbol has 0 length, using length of %lu\n",
FILE__, __LINE__, START_FUNC_NAME, START_HEURISTIC_LENGTH);
end = start + START_HEURISTIC_LENGTH;
}
sw_printf("[%s:%u] - Bottom stepper taking %lx to %lx for start\n",
FILE__, __LINE__, start, end);
ra_stack_tops.push_back(std::pair<Address, Address>(start, end));
}
}
}
if (!libthread_init)
{
LibAddrPair libthread_addr;
SymReader *libthread = NULL;
Symbol_t clone_sym, startthread_sym;
bool result = libs->getLibthread(libthread_addr);
if (result) {
libthread = fact->openSymbolReader(libthread_addr.first);
libthread_init = true;
}
if (libthread) {
clone_sym = libthread->getSymbolByName(CLONE_FUNC_NAME);
if (libthread->isValidSymbol(clone_sym)) {
Dyninst::Address start = libthread->getSymbolOffset(clone_sym) +
libthread_addr.second;
Dyninst::Address end = libthread->getSymbolSize(clone_sym) + start;
sw_printf("[%s:%u] - Bottom stepper taking %lx to %lx for clone\n",
FILE__, __LINE__, start, end);
ra_stack_tops.push_back(std::pair<Address, Address>(start, end));
}
startthread_sym = libthread->getSymbolByName(START_THREAD_FUNC_NAME);
if (libthread->isValidSymbol(startthread_sym)) {
Dyninst::Address start = libthread->getSymbolOffset(startthread_sym) +
libthread_addr.second;
Dyninst::Address end = libthread->getSymbolSize(startthread_sym) + start;
sw_printf("[%s:%u] - Bottom stepper taking %lx to %lx for start_thread\n",
FILE__, __LINE__, start, end);
ra_stack_tops.push_back(std::pair<Address, Address>(start, end));
}
}
}
}
FrameFuncHelper::alloc_frame_t aarch64_LookupFuncStart::allocatesFrame(Address addr)
{
LibAddrPair lib;
unsigned int mem[FUNCTION_PROLOG_TOCHECK/4];
Address func_addr;
unsigned cur;
int push_fp_ra_pos = -1, mov_sp_fp_pos = -1;
alloc_frame_t res = alloc_frame_t(unknown_t, unknown_s);
bool result;
SymReader *reader;
Offset off;
Symbol_t sym;
result = checkCache(addr, res);
if (result) {
sw_printf("[%s:%u] - Cached value for %lx is %d/%d\n",
FILE__, __LINE__, addr, (int) res.first, (int) res.second);
return res;
}
result = proc->getLibraryTracker()->getLibraryAtAddr(addr, lib);
if (!result)
{
sw_printf("[%s:%u] - No library at %lx\n", FILE__, __LINE__, addr);
goto done;
}
reader = LibraryWrapper::getLibrary(lib.first);
if (!reader) {
sw_printf("[%s:%u] - Failed to open symbol reader %s\n",
FILE__, __LINE__, lib.first.c_str() );
goto done;
}
off = addr - lib.second;
sym = reader->getContainingSymbol(off);
if (!reader->isValidSymbol(sym)) {
sw_printf("[%s:%u] - Could not find symbol in binary\n", FILE__, __LINE__);
goto done;
}
func_addr = reader->getSymbolOffset(sym) + lib.second;
result = proc->readMem(mem, func_addr, FUNCTION_PROLOG_TOCHECK);
if (!result) {
sw_printf("[%s:%u] - Error. Couldn't read from memory at %lx\n",
FILE__, __LINE__, func_addr);
goto done;
}
//Try to find a 'push (r|e)bp'
for (cur=0; cur<FUNCTION_PROLOG_TOCHECK/4; cur++)
{
if ( (mem[cur]&push_fp_ra_mask) == push_fp_ra )
{
push_fp_ra_pos = cur*4;
break;
}
}
//Try to find the mov esp->ebp
for (cur = cur+1; cur<FUNCTION_PROLOG_TOCHECK/4; cur++)
{
if(mem[cur] == mov_sp_fp){
mov_sp_fp_pos = cur*4;
break;
}
}
if ((push_fp_ra_pos != -1) && (mov_sp_fp_pos != -1))
res.first = standard_frame;
else if ((push_fp_ra_pos != -1) && (mov_sp_fp_pos == -1))
res.first = savefp_only_frame;
else
res.first = no_frame;
// if the addr is earlier than the frame building instructions
// mark it as unset_frame.
// on ARMv8, if the target process is not broken by BP,
// the frame type should always be set_frame, since the current
// PC should pointed to the function body, but never to the prologe.
if ((push_fp_ra_pos != -1) && (addr <= func_addr + push_fp_ra_pos))
res.second = unset_frame;
else if ((mov_sp_fp_pos != -1) && (addr <= func_addr + mov_sp_fp_pos))
res.second = halfset_frame;
else
res.second = set_frame;
done:
sw_printf("[%s:%u] - Function containing %lx has frame type %d/%d\n",
FILE__, __LINE__, addr, (int) res.first, (int) res.second);
updateCache(addr, res);
return res;
}