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);
}
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, 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 ImageSegmentRenderer CreateRenderer(ElfSection shdr, ElfMachine machine)
{
switch (shdr.Type)
{
case SectionHeaderType.SHT_DYNAMIC:
return(new DynamicSectionRenderer32(this, shdr, machine));
case SectionHeaderType.SHT_REL:
return(new RelSegmentRenderer(this, shdr));
case SectionHeaderType.SHT_RELA:
return(new RelaSegmentRenderer(this, shdr));
case SectionHeaderType.SHT_SYMTAB:
case SectionHeaderType.SHT_DYNSYM:
return(new SymtabSegmentRenderer32(this, shdr));
default: return(null);
}
}
private void DumpRel(ElfSection sh)
{
var entries = sh.Size / sh.EntrySize;
var symtab = sh.LinkedSection;
var rdr = CreateReader(sh.FileOffset);
for (ulong i = 0; i < entries; ++i)
{
if (!rdr.TryReadUInt64(out ulong offset))
{
return;
}
if (!rdr.TryReadUInt64(out ulong info))
{
return;
}
ulong sym = info >> 8;
string symStr = GetStrPtr(symtab !, sym);
ElfImageLoader.trace.Verbose(" RELA {0:X16} {1,3} {2:X16} {3}", offset, info & 0xFF, sym, symStr);
}
}
public override Dictionary <int, ElfSymbol> LoadSymbolsSection(ElfSection symSection)
{
ElfImageLoader.trace.Inform("== Symbols from {0} ==", symSection.Name);
var symbols = new Dictionary <int, ElfSymbol>();
var stringtableSection = symSection.LinkedSection !;
var rdr = CreateReader(symSection.FileOffset);
for (ulong i = 0; i < symSection.Size / symSection.EntrySize; ++i)
{
if (!Elf64_Sym.TryLoad(rdr, out var sym))
{
ElfImageLoader.trace.Warn("Unable to load symbol entry {0} from {1}", i, symSection.Name);
continue;
}
var name = RemoveModuleSuffix(ReadAsciiString(stringtableSection.FileOffset + sym.st_name));
ElfImageLoader.trace.Verbose(" {0,3} {1,-25} {2,-12} {3,6} {4} {5,-15} {6:X16} {7,9}",
i,
string.IsNullOrWhiteSpace(name) ? "<empty>" : name,
(ElfSymbolType)(sym.st_info & 0xF),
sym.st_shndx,
GetBindingName((ElfSymbolBinding)(sym.st_info >> 4)),
GetSectionName(sym.st_shndx),
sym.st_value,
sym.st_size);
var esym = new ElfSymbol(name)
{
Type = (ElfSymbolType)(sym.st_info & 0xF),
Bind = (ElfSymbolBinding)(sym.st_info >> 4),
SectionIndex = sym.st_shndx,
Value = sym.st_value,
Size = sym.st_size,
};
symbols.Add((int)i, esym);
}
return(symbols);
}
/// <summary>
/// Allocate the space required by SHN_COMMON symbols into a
/// synthesized section called ".reko.common", and which will
/// be placed into its own segment later.
/// </summary>
private void CollectCommonSymbolsIntoSection()
{
var rekoCommon = new ElfSection
{
Name = ".reko.common",
Number = (uint)loader.Sections.Count,
Type = SectionHeaderType.SHT_NOBITS,
Flags = ElfLoader.SHF_WRITE | ElfLoader.SHF_ALLOC | ElfLoader.SHF_REKOCOMMON,
FileOffset = 0,
Size = 0,
};
foreach (var sym in loader.GetAllSymbols().Where(s => s.SectionIndex == 0xFFF2))
{
rekoCommon.Size = Align(rekoCommon.Size, sym.Value);
sym.Value = (uint)rekoCommon.Size;
sym.SectionIndex = (uint)loader.Sections.Count;
rekoCommon.Size += sym.Size;
}
if (rekoCommon.Size > 0)
{
loader.Sections.Add(rekoCommon);
}
}
/// <summary>
/// Allocate the space required by SHN_COMMON symbols into a
/// synthesized section called ".reko.common", and which will
/// be placed into its own segment later.
/// </summary>
private void CollectCommonSymbolsIntoSection()
{
var rekoCommon = new ElfSection
{
Name = ".reko.common",
Number = (uint) loader.Sections.Count,
Type = SectionHeaderType.SHT_NOBITS,
Flags = ElfLoader.SHF_WRITE | ElfLoader.SHF_ALLOC | ElfLoader.SHF_REKOCOMMON,
FileOffset = 0,
Size = 0,
};
foreach (var sym in loader.GetAllSymbols().Where(s => s.SectionIndex == 0xFFF2))
{
rekoCommon.Size = Align(rekoCommon.Size, sym.Value);
sym.Value = (uint) rekoCommon.Size;
sym.SectionIndex = (uint) loader.Sections.Count;
rekoCommon.Size += sym.Size;
}
if (rekoCommon.Size > 0)
{
loader.Sections.Add(rekoCommon);
}
}
public override void LoadSectionHeaders()
{
// Create the sections.
var inames = new List<uint>();
var links = new List<uint>();
var infos = new List<uint>();
var rdr = imgLoader.CreateReader(Header64.e_shoff);
for (uint i = 0; i < Header64.e_shnum; ++i)
{
var shdr = Elf64_SHdr.Load(rdr);
var section = new ElfSection
{
Number = i,
Type = shdr.sh_type,
Flags = shdr.sh_flags,
Address = shdr.sh_addr != 0
? platform.MakeAddressFromLinear(shdr.sh_addr)
: null,
FileOffset = shdr.sh_offset,
Size = shdr.sh_size,
Alignment = shdr.sh_addralign,
EntrySize = shdr.sh_entsize,
};
Sections.Add(section);
inames.Add(shdr.sh_name);
links.Add(shdr.sh_link);
infos.Add(shdr.sh_info);
}
// Get section names and crosslink sections.
for (int i = 0; i < Sections.Count; ++i)
{
var section = Sections[i];
section.Name = ReadSectionName(inames[i]);
ElfSection linkSection = null;
ElfSection relSection = null;
switch (section.Type)
{
case SectionHeaderType.SHT_REL:
case SectionHeaderType.SHT_RELA:
linkSection = GetSectionByIndex(links[i]);
relSection = GetSectionByIndex(infos[i]);
break;
case SectionHeaderType.SHT_DYNAMIC:
case SectionHeaderType.SHT_HASH:
case SectionHeaderType.SHT_SYMTAB:
case SectionHeaderType.SHT_DYNSYM:
linkSection = GetSectionByIndex(links[i]);
break;
}
section.LinkedSection = linkSection;
section.RelocatedSection = relSection;
}
}
public string GetSymbolName(ElfSection symSection, uint symbolNo)
{
var strSection = symSection.LinkedSection;
uint offset = (uint)(symSection.FileOffset + symbolNo * symSection.EntrySize);
var rdr = imgLoader.CreateReader(offset);
rdr.TryReadUInt32(out offset);
return GetStrPtr(strSection, offset);
}
public abstract Dictionary <int, ElfSymbol> LoadSymbolsSection(ElfSection symSection);
public override void RelocateEntry(Program program, ElfSymbol symbol, ElfSection referringSection, Elf32_Rela rela)
{
throw new NotImplementedException();
}
public override void Render(ImageSegment segment, Program program, Formatter formatter)
{
// Get the entry that has the segment# for the string table.
var dynStrtab = loader.GetDynEntries64(shdr.FileOffset).Where(d => d.d_tag == DT_STRTAB).FirstOrDefault();
if (dynStrtab == null)
return;
this.strtabSection = loader.GetSectionInfoByAddr64(dynStrtab.d_ptr);
foreach (var entry in loader.GetDynEntries64(shdr.FileOffset))
{
DtFormat fmt;
string entryName;
Entry dser;
if (!entries.TryGetValue(entry.d_tag, out dser))
{
entryName = string.Format("{0:X8} ", entry.d_tag);
fmt = DtFormat.Hexadecimal;
}
else
{
entryName = dser.Name;
fmt = dser.Format;
}
RenderEntry(entryName, fmt, entry, formatter);
formatter.WriteLine();
}
}
public DynamicSectionRenderer32(ElfLoader32 loader, ElfSection shdr, ElfMachine machine)
{
this.loader = loader;
this.shdr = shdr;
if (!machineSpecificEntries.TryGetValue(machine, out machineSpecific))
{
machineSpecific = new Dictionary<long, Entry>();
}
}
public virtual void RelocateEntry(ElfSymbol symbol, ElfSection referringSection, Elf64_Rela rela)
{
throw new NotImplementedException();
}
public override void RelocateEntry(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);
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;
default:
throw new NotImplementedException(string.Format(
"SPARC ELF relocation type {0} not implemented yet.",
rt));
}
var w = relR.ReadBeUInt32();
w += ((uint)(S + A + P) >> sh) & mask;
relW.WriteBeUInt32(w);
}
private ImageSegmentRenderer CreateRenderer64(ElfSection shdr)
{
switch (shdr.Type)
{
case SectionHeaderType.SHT_DYNAMIC:
return new DynamicSectionRenderer64(this, shdr);
case SectionHeaderType.SHT_RELA:
return new RelaSegmentRenderer64(this, shdr);
case SectionHeaderType.SHT_SYMTAB:
case SectionHeaderType.SHT_DYNSYM:
return new SymtabSegmentRenderer64(this, shdr);
default: return null;
}
}
public RelaSegmentRenderer64(ElfLoader64 loader, ElfSection shdr)
{
this.loader = loader;
this.shdr = shdr;
}
public abstract void RelocateEntry(Program program, ElfSymbol symbol, ElfSection referringSection, Elf32_Rela rela);
public override List<ElfSymbol> LoadSymbolsSection(ElfSection symSection)
{
//Debug.Print("Symbols");
var stringtableSection = symSection.LinkedSection;
var rdr = CreateReader(symSection.FileOffset);
var symbols = new List<ElfSymbol>();
for (ulong i = 0; i < symSection.Size / symSection.EntrySize; ++i)
{
var sym = Elf64_Sym.Load(rdr);
//Debug.Print(" {0,3} {1,-25} {2,-12} {3,6} {4,-15} {5:X8} {6,9}",
// i,
// ReadAsciiString(stringtableSection.FileOffset + sym.st_name),
// (ElfSymbolType)(sym.st_info & 0xF),
// sym.st_shndx,
// GetSectionName(sym.st_shndx),
// sym.st_value,
// sym.st_size);
symbols.Add(new ElfSymbol
{
Name = ReadAsciiString(stringtableSection.FileOffset + sym.st_name),
Type = (ElfSymbolType)(sym.st_info & 0xF),
SectionIndex = sym.st_shndx,
Value = sym.st_value,
Size = sym.st_size,
});
}
return symbols;
}
/// <summary>
/// Allocate an arbitrary 16 bytes for each unresolved
/// external symbol.
/// </summary>
private void CollectUndefinedSymbolsIntoSection()
{
var rekoExtfn = new ElfSection
{
Name = ".reko.externs",
Number = (uint) loader.Sections.Count,
Type = SectionHeaderType.SHT_NOBITS,
Flags = ElfLoader.SHF_ALLOC | ElfLoader.SHF_EXECINSTR,
FileOffset = 0,
Size = 0,
Alignment = 0x10,
};
foreach (var sym in loader.GetAllSymbols().Where(s =>
s.Type == ElfSymbolType.STT_NOTYPE &&
!string.IsNullOrEmpty(s.Name)))
{
rekoExtfn.Size = Align(rekoExtfn.Size, 0x10);
sym.Value = (uint) rekoExtfn.Size;
sym.SectionIndex = (uint)loader.Sections.Count;
rekoExtfn.Size += 0x10;
}
if (rekoExtfn.Size > 0)
{
loader.Sections.Add(rekoExtfn);
}
}
public string GetStrPtr(ElfSection section, ulong offset)
{
if (section == null)
{
// Most commonly, this will be an index of -1, because a call to GetSectionIndexByName() failed
throw new ArgumentNullException("section");
}
// Get a pointer to the start of the string table and add the offset
return imgLoader.ReadAsciiString(section.FileOffset + offset);
}
public RelSegmentRenderer(ElfLoader32 loader, ElfSection shdr)
{
this.loader = loader;
this.shdr = shdr;
}
public DynamicSectionRenderer64(ElfLoader64 loader, ElfSection shdr)
{
this.loader = loader;
this.shdr = shdr;
}
public abstract void RelocateEntry(Program program, ElfSymbol symbol, ElfSection referringSection, Elf32_Rela rela);
public RelaSegmentRenderer(ElfLoader32 imgLoader, ElfSection shdr)
{
this.loader = imgLoader;
this.shdr = shdr;
}
private void DumpRela(ElfSection sh)
{
var entries = sh.Size / sh.EntrySize;
var symtab = sh.LinkedSection;
var rdr = imgLoader.CreateReader(sh.FileOffset);
for (ulong i = 0; i < entries; ++i)
{
uint offset;
if (!rdr.TryReadUInt32(out offset))
return;
uint info;
if (!rdr.TryReadUInt32(out info))
return;
int addend;
if (!rdr.TryReadInt32(out addend))
return;
uint sym = info >> 8;
string symStr = GetStrPtr(symtab, sym);
Debug.Print(" RELA {0:X8} {1,3} {2:X8} {3:X8} {4}", offset, info & 0xFF, sym, addend, symStr);
}
}
public abstract List<ElfSymbol> LoadSymbolsSection(ElfSection symSection);
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 DynamicSectionRenderer64(ElfLoader64 loader, ElfSection shdr)
{
this.loader = loader;
this.shdr = shdr;
}
public override List <ElfSection> LoadSectionHeaders()
{
// Create the sections.
var inames = new List <uint>();
var links = new List <uint>();
var infos = new List <uint>();
var sections = new List <ElfSection>();
var rdr = CreateReader(Header.e_shoff);
for (uint i = 0; i < Header.e_shnum; ++i)
{
var shdr = Elf32_SHdr.Load(rdr);
if (shdr == null)
{
break;
}
var section = new ElfSection
{
Number = i,
Type = shdr.sh_type,
Flags = shdr.sh_flags,
Address = Address.Ptr32(shdr.sh_addr),
FileOffset = shdr.sh_offset,
Size = shdr.sh_size,
Alignment = shdr.sh_addralign,
EntrySize = shdr.sh_entsize,
};
sections.Add(section);
inames.Add(shdr.sh_name);
links.Add(shdr.sh_link);
infos.Add(shdr.sh_info);
}
// Get section names and crosslink sections.
for (int i = 0; i < sections.Count; ++i)
{
var section = sections[i];
section.Name = ReadSectionName(sections, inames[i]);
ElfSection linkSection = null;
ElfSection relSection = null;
switch (section.Type)
{
case SectionHeaderType.SHT_REL:
case SectionHeaderType.SHT_RELA:
linkSection = GetSectionByIndex(sections, links[i]);
relSection = GetSectionByIndex(sections, infos[i]);
break;
case SectionHeaderType.SHT_DYNAMIC:
case SectionHeaderType.SHT_HASH:
case SectionHeaderType.SHT_SYMTAB:
case SectionHeaderType.SHT_DYNSYM:
linkSection = GetSectionByIndex(sections, links[i]);
break;
}
section.LinkedSection = linkSection;
section.RelocatedSection = relSection;
}
return(sections);
}
public override void RelocateEntry(ElfSymbol symbol, ElfSection referringSection, Elf32_Rela rela)
{
throw new NotImplementedException();
}
public string GetSymbol64(ElfSection symSection, ulong symbolNo)
{
var strSection = symSection.LinkedSection;
ulong offset = symSection.FileOffset + symbolNo * symSection.EntrySize;
var rdr = imgLoader.CreateReader(offset);
rdr.TryReadUInt64(out offset);
return GetStrPtr(symSection.LinkedSection, (uint)offset);
}
public SymtabSegmentRenderer64(ElfLoader64 loader, ElfSection shdr)
{
this.loader = loader;
this.shdr = shdr;
}
public override void RelocateEntry(Program program, ElfSymbol symbol, ElfSection referringSection, Elf32_Rela rela)
{
switch ((PpcRt)(rela.r_info & 0xFF))
{
case PpcRt.R_PPC_GLOB_DAT:
case PpcRt.R_PPC_COPY:
case PpcRt.R_PPC_JMP_SLOT:
break;
default:
throw new NotImplementedException();
}
}
