public GlobalDataWorkItem(IScanner scanner, Program program, Address addr, DataType dt) : base(addr)
{
this.scanner = scanner;
this.program = program;
this.dt = dt;
this.rdr = program.CreateImageReader(addr);
}
public override void RelocateEntry(Program program, ElfSymbol sym, ElfSection referringSection, Elf32_Rela rela)
{
if (loader.Sections.Count <= sym.SectionIndex)
return;
if (sym.SectionIndex == 0)
return;
var symSection = loader.Sections[(int)sym.SectionIndex];
uint S = (uint)sym.Value + symSection.Address.ToUInt32();
int A = 0;
int sh = 0;
uint mask = ~0u;
var addr = referringSection.Address + rela.r_offset;
uint P = (uint)addr.ToLinear();
uint PP = P;
var relR = program.CreateImageReader(addr);
var relW = program.CreateImageWriter(addr);
var rt = (i386Rt)(rela.r_info & 0xFF);
switch (rt)
{
case i386Rt.R_386_NONE: // just ignore (common)
break;
case i386Rt.R_386_32: // S + A
// Read the symTabIndex'th symbol.
A = rela.r_addend;
P = 0;
break;
case i386Rt.R_386_PC32: // S + A - P
if (sym.Value == 0)
{
// This means that the symbol doesn't exist in this module, and is not accessed
// through the PLT, i.e. it will be statically linked, e.g. strcmp. We have the
// name of the symbol right here in the symbol table entry, but the only way
// to communicate with the loader is through the target address of the call.
// So we use some very improbable addresses (e.g. -1, -2, etc) and give them entries
// in the symbol table
//S = nextFakeLibAddr--; // Allocate a new fake address
//loader.AddSymbol(S, sym.Name);
//}
}
A = rela.r_addend;
P = ~P + 1;
break;
case i386Rt.R_386_GLOB_DAT:
// This relocation type is used to set a global offset table entry to the address of the
// specified symbol. The special relocation type allows one to determine the
// correspondence between symbols and global offset table entries.
P = 0;
break;
default:
throw new NotImplementedException(string.Format(
"i386 ELF relocation type {0} not implemented yet.",
rt));
}
var w = relR.ReadBeUInt32();
w += ((uint)(S + A + P) >> sh) & mask;
relW.WriteBeUInt32(w);
}
public override void RelocateEntry(Program program, ElfSymbol sym, ElfSection referringSection, Elf32_Rela rela)
{
if (loader.Sections.Count <= sym.SectionIndex)
return;
if (sym.SectionIndex == 0)
return;
var symSection = loader.Sections[(int)sym.SectionIndex];
uint S = (uint)sym.Value + symSection.Address.ToUInt32();
int A = 0;
int sh = 0;
uint mask = ~0u;
var addr = referringSection.Address + rela.r_offset;
uint P = (uint)addr.ToLinear();
uint PP = P;
Debug.Print(" off:{0:X8} type:{1,-16} add:{3,-20} {4,3} {2} {5}",
rela.r_offset,
(SparcRt)(rela.r_info & 0xFF),
sym.Name,
rela.r_addend,
(int)(rela.r_info >> 8),
symSection.Name);
var rt = (SparcRt)(rela.r_info & 0xFF);
switch (rt)
{
case 0:
return;
case SparcRt.R_SPARC_HI22:
A = rela.r_addend;
sh = 10;
P = 0;
break;
case SparcRt.R_SPARC_LO10:
A = rela.r_addend;
mask = 0x3FF;
P = 0;
break;
case SparcRt.R_SPARC_WDISP30:
A = rela.r_addend;
P = ~P + 1;
sh = 2;
break;
case SparcRt.R_SPARC_COPY:
Debug.Print("Relocation type {0} not handled yet.", rt);
return;
default:
throw new NotImplementedException(string.Format(
"SPARC ELF relocation type {0} not implemented yet.",
rt));
}
var relR = program.CreateImageReader(addr);
var relW = program.CreateImageWriter(addr);
var w = relR.ReadBeUInt32();
w += ((uint)(S + A + P) >> sh) & mask;
relW.WriteBeUInt32(w);
}
private static string BuildBytes(Program program, MachineInstruction instr)
{
var sb = new StringBuilder();
var rdr = program.CreateImageReader(instr.Address);
for (int i = 0; i < instr.Length; ++i)
{
sb.AppendFormat("{0:X2} ", rdr.ReadByte());
}
return sb.ToString();
}
public override void RelocateEntry(Program program, ElfSymbol sym, ElfSection referringSection, Elf64_Rela rela)
{
if (loader.Sections.Count <= sym.SectionIndex)
return;
if (sym.SectionIndex == 0)
return;
var symSection = loader.Sections[(int)sym.SectionIndex];
ulong S = (ulong)sym.Value + symSection.Address.ToLinear();
long A = 0;
int sh = 0;
uint mask = ~0u;
Address addr;
ulong P;
ImageReader relR;
ImageWriter relW;
if (referringSection.Address != null)
{
addr = referringSection.Address + rela.r_offset;
P = addr.ToLinear();
relR = program.CreateImageReader(addr);
relW = program.CreateImageWriter(addr);
}
else
{
addr = null;
P = 0;
relR = null;
relW = null;
}
ulong PP = P;
var rt = (x86_64Rt)(rela.r_info & 0xFF);
switch (rt)
{
case x86_64Rt.R_X86_64_NONE: // just ignore (common)
break;
case x86_64Rt.R_X86_64_COPY:
break;
default:
Debug.Print("x86_64 ELF relocation type {0} not implemented yet.",
rt);
break;
//throw new NotImplementedException(string.Format(
// "x86_64 ELF relocation type {0} not implemented yet.",
// rt));
}
if (relR != null)
{
var w = relR.ReadUInt64();
w += ((ulong)(S + (ulong)A + P) >> sh) & mask;
relW.WriteUInt64(w);
}
}
public override void LocateGotPointers(Program program, SortedList<Address, ImageSymbol> symbols)
{
// Locate the GOT
//$REVIEW: there doesn't seem to be a reliable way to get that
// information.
var got = program.SegmentMap.Segments.Values.FirstOrDefault(s => s.Name == ".got");
if (got == null)
return;
var rdr = program.CreateImageReader(got.Address);
while (rdr.Address < got.EndAddress)
{
var addrGot = rdr.Address;
ulong uAddrSym;
if (!rdr.TryReadUInt64(out uAddrSym))
break;
var addrSym = Address.Ptr64(uAddrSym);
ImageSymbol symbol;
if (symbols.TryGetValue(addrSym, out symbol))
{
// This GOT entry is a known symbol!
if (symbol.Type == SymbolType.Procedure)
{
//$TODO: look up function signature.
var gotSym = new ImageSymbol(addrGot, symbol.Name + "_GOT", new Pointer(new CodeType(), 4));
symbols[addrGot] = gotSym;
Debug.Print("Found GOT entry at {0}, changing symbol at {1}", gotSym, symbol);
}
}
}
}