github/ghidra
1
1
Fork 0
mirror of https://github.com/NationalSecurityAgency/ghidra.git synced 2026-01-09 14:08:03 -05:00
Code Issues Packages Projects Releases Wiki Activity

Merge remote-tracking branch 'origin/GP-3834_JumptableByte'

Browse Source 
(Closes #5494)
This commit is contained in:
Ryan Kurtz
2025-12-18 07:09:45 -05:00
parent 2f06823fba b8e698d978
commit 0a94a47efb
3 changed files with 24 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
Ghidra/Features/Decompiler/src/decompile/cpp/jumptable.cc
View File

@@ -1030,6 +1030,21 @@ PcodeOp *PathMeld::getEarliestOp(int4 pos) const
return (PcodeOp *)0;
}
/// Search for a Varnode in the common path, prior to the given point, defined by a LOAD operation.
/// \param i is the given point in the path
/// \return \b true if a LOAD is present
bool PathMeld::isLoadInPath(int4 i) const
{
while(i > 0) {
i -= 1;
Varnode *vn = commonVn[i];
if (!vn->isWritten()) continue;
if (vn->getDef()->code() == CPUI_LOAD) return true;
}
return false;
}
/// \brief Analyze CBRANCHs leading up to the given basic-block as a potential switch \e guard.
///
/// In general there is only one path to the switch, and the given basic-block will
@@ -1180,8 +1195,10 @@ void JumpBasic::findSmallestNormal(uint4 matchsize)
calcRange(pathMeld.getVarnode(i),rng);
sz = rng.getSize();
if (sz < maxsize) {
// Don't let a 1-byte switch variable get thru without a guard
if ((sz != 256)||(pathMeld.getVarnode(i)->getSize()!=1)) {
// Don't accept a 1-byte switch variable unless there is an explicit guard
// or a table lookup between the byte and the indirect jump.
// "goto *(#const + byteVar)" should not be interpreted as 256 case switch
if (sz != 256 || pathMeld.getVarnode(i)->getSize()!=1 || pathMeld.isLoadInPath(i)) {
varnodeIndex = i;
maxsize = sz;
jrange->setRange(rng);

1
Ghidra/Features/Decompiler/src/decompile/cpp/jumptable.hh
View File

@@ -98,6 +98,7 @@ public:
Varnode *getOpParent(int4 i) const { return commonVn[ opMeld[i].rootVn ]; } ///< Get the split-point for the i-th PcodeOp
PcodeOp *getOp(int4 i) const { return opMeld[i].op; } ///< Get the i-th PcodeOp
PcodeOp *getEarliestOp(int4 pos) const; ///< Find \e earliest PcodeOp that has a specific common Varnode as input
bool isLoadInPath(int4 i) const; ///< Return \b true if a LOAD exists in the common path
bool empty(void) const { return commonVn.empty(); } ///< Return \b true if \b this container holds no paths
};

5
Ghidra/Features/Decompiler/src/decompile/cpp/type.cc
View File

@@ -4630,6 +4630,9 @@ void TypeFactory::decodeAlignmentMap(Decoder &decoder)
alignMap[sz] = val;
decoder.closeElement(mapId);
}
if (alignMap.empty())
throw LowlevelError("Alignment map empty");
alignMap[0] = 1;
int4 curAlign = 1;
for(int4 sz=1;sz < alignMap.size();++sz) {
int4 tmpAlign = alignMap[sz];
@@ -4644,7 +4647,7 @@ void TypeFactory::decodeAlignmentMap(Decoder &decoder)
void TypeFactory::setDefaultAlignmentMap(void)
{
alignMap.resize(9,0);
alignMap.resize(9,1);
alignMap[1] = 1;
alignMap[2] = 2;
alignMap[3] = 2;