yetangitu/ghidra
1
0
Fork 0
mirror of https://github.com/NationalSecurityAgency/ghidra.git synced 2025-10-04 18:29:37 +02:00
Code Issues Releases Wiki Activity

don't create COPY in ActionConstantPtr

Browse source
This commit is contained in:
caheckman 2019-09-16 11:32:45 -04:00
parent 8a77197187
commit e2a9e9db84
1 changed files with 65 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

88
Ghidra/Features/Decompiler/src/decompile/cpp/funcdata.cc
View file

@ -290,7 +290,6 @@ Varnode *Funcdata::findSpacebaseInput(AddrSpace *id) const
void Funcdata::spacebaseConstant(PcodeOp *op,int4 slot,SymbolEntry *entry,const Address &rampoint,uintb origval,int4 origsize)
{
PcodeOp *addop;
int4 sz = rampoint.getAddrSize();
AddrSpace *spaceid = rampoint.getSpace();
Datatype *sb_type = glb->types->getTypeSpacebase(spaceid,Address());
@ -300,21 +299,47 @@ void Funcdata::spacebaseConstant(PcodeOp *op,int4 slot,SymbolEntry *entry,const
uintb extra = rampoint.getOffset() - entry->getAddr().getOffset(); // Offset from beginning of entry
extra = AddrSpace::byteToAddress(extra,rampoint.getSpace()->getWordSize()); // Convert to address units
PcodeOp *addOp = (PcodeOp *)0;
PcodeOp *extraOp = (PcodeOp *)0;
PcodeOp *zextOp = (PcodeOp *)0;
PcodeOp *subOp = (PcodeOp *)0;
bool isCopy = false;
if (op->code() == CPUI_COPY) { // We replace COPY with final op of this calculation
isCopy = true;
if (sz < origsize)
zextOp = op;
else {
op->insertInput(1); // PTRSUB, ADD, SUBPIECE all take 2 parameters
if (origsize < sz)
subOp = op;
else if (extra != 0)
extraOp = op;
else
addOp = op;
}
}
spacebase_vn = newConstant(sz,0);
spacebase_vn->updateType(sb_type,true,true);
spacebase_vn->setFlags(Varnode::spacebase);
addop = newOp(2,op->getAddr());
opSetOpcode(addop,CPUI_PTRSUB);
outvn = newUniqueOut(sz,addop);
if (addOp == (PcodeOp *)0) {
addOp = newOp(2,op->getAddr());
opSetOpcode(addOp,CPUI_PTRSUB);
newUniqueOut(sz,addOp);
opInsertBefore(addOp,op);
}
else {
opSetOpcode(addOp,CPUI_PTRSUB);
}
outvn = addOp->getOut();
// Make sure newconstant and extra preserve origval in address units
uintb newconstoff = origval - extra; // everything is already in address units
newconst = newConstant(sz,newconstoff);
newconst->setPtrCheck(); // No longer need to check this constant as a pointer
if (spaceid->isTruncated())
addop->setPtrFlow();
opSetInput(addop,spacebase_vn,0);
opSetInput(addop,newconst,1);
opInsertBefore(addop,op);
addOp->setPtrFlow();
opSetInput(addOp,spacebase_vn,0);
opSetInput(addOp,newconst,1);
Symbol *sym = entry->getSymbol();
Datatype *entrytype = sym->getType();
Datatype *ptrentrytype = glb->types->getTypePointer(sz,entrytype,spaceid->getWordSize());
@ -323,33 +348,46 @@ void Funcdata::spacebaseConstant(PcodeOp *op,int4 slot,SymbolEntry *entry,const
typelock = false;
outvn->updateType(ptrentrytype,typelock,true);
if (extra != 0) {
PcodeOp *extraop = newOp(2,op->getAddr());
opSetOpcode(extraop,CPUI_INT_ADD);
Varnode *outvn2 = newUniqueOut(sz,extraop);
if (extraOp == (PcodeOp *)0) {
extraOp = newOp(2,op->getAddr());
opSetOpcode(extraOp,CPUI_INT_ADD);
newUniqueOut(sz,extraOp);
opInsertBefore(extraOp,op);
}
else
opSetOpcode(extraOp,CPUI_INT_ADD);
Varnode *extconst = newConstant(sz,extra);
extconst->setPtrCheck();
opSetInput(extraop,outvn,0);
opSetInput(extraop,extconst,1);
outvn = outvn2;
opInsertBefore(extraop,op);
opSetInput(extraOp,outvn,0);
opSetInput(extraOp,extconst,1);
outvn = extraOp->getOut();
}
if (sz < origsize) { // The new constant is smaller than the original varnode, so we extend it
PcodeOp *zextop = newOp(1,op->getAddr());
Varnode *outvn2 = newUniqueOut(origsize,zextop);
opSetOpcode(zextop,CPUI_INT_ZEXT); // Create an extension to get back to original varnode size
opSetInput(zextop,outvn,0);
opInsertBefore(zextop,op);
outvn = outvn2;
if (zextOp == (PcodeOp *)0) {
zextOp = newOp(1,op->getAddr());
opSetOpcode(zextOp,CPUI_INT_ZEXT); // Create an extension to get back to original varnode size
newUniqueOut(origsize,zextOp);
opInsertBefore(zextOp,op);
}
else
opSetOpcode(extraOp,CPUI_INT_ZEXT);
opSetInput(zextOp,outvn,0);
outvn = zextOp->getOut();
}
else if (origsize < sz) { // The new constant is bigger than the original varnode, truncate it
PcodeOp *subOp = newOp(2,op->getAddr());
Varnode *outvn3 = newUniqueOut(origsize,subOp);
if (subOp == (PcodeOp *)0) {
subOp = newOp(2,op->getAddr());
opSetOpcode(subOp,CPUI_SUBPIECE);
newUniqueOut(origsize,subOp);
opInsertBefore(subOp,op);
}
else
opSetOpcode(subOp,CPUI_SUBPIECE);
opSetInput(subOp,outvn,0);
opSetInput(subOp,newConstant(4, 0), 1); // Take least significant piece
opInsertBefore(subOp,op);
outvn = outvn3;
outvn = subOp->getOut();
}
if (!isCopy)
opSetInput(op,outvn,slot);
}