Runtime dylib simple ARM 24-bit branch relocation support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128184 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2011-03-23 23:35:17 +00:00
parent 36dca60f5c
commit 5ffe37f2c7

View File

@ -207,13 +207,28 @@ bool RuntimeDyldImpl::resolveARMRelocation(intptr_t Address, intptr_t Value,
*p++ = (uint8_t)Value;
Value >>= 8;
}
return false;
break;
}
case macho::RIT_Pair:
case macho::RIT_Difference:
case macho::RIT_ARM_LocalDifference:
case macho::RIT_ARM_PreboundLazyPointer:
case macho::RIT_ARM_Branch24Bit:
case macho::RIT_ARM_Branch24Bit: {
// Mask the value into the target address. We know instructions are
// 32-bit aligned, so we can do it all at once.
uint32_t *p = (uint32_t*)Address;
// The low two bits of the value are not encoded.
Value >>= 2;
// Mask the value to 24 bits.
Value &= 0xffffff;
// FIXME: If the destination is a Thumb function (and the instruction
// is a non-predicated BL instruction), we need to change it to a BLX
// instruction instead.
// Insert the value into the instruction.
*p = (*p & ~0xffffff) | Value;
break;
}
case macho::RIT_ARM_ThumbBranch22Bit:
case macho::RIT_ARM_ThumbBranch32Bit:
case macho::RIT_ARM_Half:
@ -243,7 +258,11 @@ loadSegment32(const MachOObject *Obj,
memset((char*)Data.base() + Segment32LC->FileSize, 0,
Segment32LC->VMSize - Segment32LC->FileSize);
// Bind the section indices to address.
// Bind the section indices to addresses and record the relocations we
// need to resolve.
typedef std::pair<uint32_t, macho::RelocationEntry> RelocationMap;
SmallVector<RelocationMap, 64> Relocations;
SmallVector<void *, 16> SectionBases;
for (unsigned i = 0; i != Segment32LC->NumSections; ++i) {
InMemoryStruct<macho::Section> Sect;
@ -251,33 +270,42 @@ loadSegment32(const MachOObject *Obj,
if (!Sect)
return Error("unable to load section: '" + Twine(i) + "'");
// FIXME: We don't support relocations yet.
if (Sect->NumRelocationTableEntries != 0)
return Error("not yet implemented: relocations!");
// Remember any relocations the section has so we can resolve them later.
for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
InMemoryStruct<macho::RelocationEntry> RE;
Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
Relocations.push_back(RelocationMap(j, *RE));
}
// FIXME: Improve check.
if (Sect->Flags != 0x80000400)
return Error("unsupported section type!");
// if (Sect->Flags != 0x80000400)
// return Error("unsupported section type!");
SectionBases.push_back((char*) Data.base() + Sect->Address);
}
// Bind all the symbols to address.
// Bind all the symbols to address. Keep a record of the names for use
// by relocation resolution.
SmallVector<StringRef, 64> SymbolNames;
for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
InMemoryStruct<macho::SymbolTableEntry> STE;
Obj->ReadSymbolTableEntry(SymtabLC->SymbolTableOffset, i, STE);
if (!STE)
return Error("unable to read symbol: '" + Twine(i) + "'");
// Get the symbol name.
StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
SymbolNames.push_back(Name);
// Just skip undefined symbols. They'll be loaded from whatever
// module they come from (or system dylib) when we resolve relocations
// involving them.
if (STE->SectionIndex == 0)
return Error("unexpected undefined symbol!");
continue;
unsigned Index = STE->SectionIndex - 1;
if (Index >= Segment32LC->NumSections)
return Error("invalid section index for symbol: '" + Twine() + "'");
// Get the symbol name.
StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
// Get the section base address.
void *SectionBase = SectionBases[Index];
@ -295,6 +323,13 @@ loadSegment32(const MachOObject *Obj,
SymbolTable[Name] = Address;
}
// Now resolve any relocations.
for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
if (resolveRelocation(Relocations[i].first, Relocations[i].second,
SectionBases, SymbolNames))
return true;
}
// We've loaded the section; now mark the functions in it as executable.
// FIXME: We really should use the JITMemoryManager for this.
sys::Memory::setRangeExecutable(Data.base(), Data.size());
@ -335,7 +370,7 @@ loadSegment64(const MachOObject *Obj,
if (!Sect)
return Error("unable to load section: '" + Twine(i) + "'");
// Resolve any relocations the section has.
// Remember any relocations the section has so we can resolve them later.
for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
InMemoryStruct<macho::RelocationEntry> RE;
Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);