140 changes: 140 additions & 0 deletions lld/lib/ReaderWriter/MachO/TLVPass.cpp
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//===- lib/ReaderWriter/MachO/TLVPass.cpp ---------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This linker pass transforms all TLV references to real references.
///
//===----------------------------------------------------------------------===//

#include "ArchHandler.h"
#include "File.h"
#include "MachOPasses.h"
#include "lld/Core/Simple.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Debug.h"

namespace lld {
namespace mach_o {

//
// TLVP Entry Atom created by the TLV pass.
//
class TLVPEntryAtom : public SimpleDefinedAtom {
public:
TLVPEntryAtom(const File &file, bool is64, StringRef name)
: SimpleDefinedAtom(file), _is64(is64), _name(name) {}

ContentType contentType() const override {
return DefinedAtom::typeTLVInitializerPtr;
}

Alignment alignment() const override {
return _is64 ? 8 : 4;
}

uint64_t size() const override {
return _is64 ? 8 : 4;
}

ContentPermissions permissions() const override {
return DefinedAtom::permRW_;
}

ArrayRef<uint8_t> rawContent() const override {
static const uint8_t zeros[] =
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
return llvm::makeArrayRef(zeros, size());
}

StringRef slotName() const {
return _name;
}

private:
const bool _is64;
StringRef _name;
};

class TLVPass : public Pass {
public:
TLVPass(const MachOLinkingContext &context)
: _ctx(context), _archHandler(_ctx.archHandler()),
_file("<mach-o TLV Pass>") {}

private:

std::error_code perform(SimpleFile &mergedFile) override {

bool allowTLV = _ctx.minOS("10.7", "1.0");

for (const DefinedAtom *atom : mergedFile.defined()) {
for (const Reference *ref : *atom) {
if (!_archHandler.isTLVAccess(*ref))
continue;

if (!allowTLV)
return make_dynamic_error_code(
"targeted OS version does not support use of thread local "
"variables in " + atom->name() + " for architecture " +
_ctx.archName());

const Atom *target = ref->target();
assert(target != nullptr);

const DefinedAtom *tlvpEntry = makeTLVPEntry(target);
const_cast<Reference*>(ref)->setTarget(tlvpEntry);
_archHandler.updateReferenceToTLV(ref);
}
}

std::vector<const TLVPEntryAtom*> entries;
entries.reserve(_targetToTLVP.size());
for (auto &it : _targetToTLVP)
entries.push_back(it.second);
std::sort(entries.begin(), entries.end(),
[](const TLVPEntryAtom *lhs, const TLVPEntryAtom *rhs) {
return (lhs->slotName().compare(rhs->slotName()) < 0);
});

for (const TLVPEntryAtom *slot : entries)
mergedFile.addAtom(*slot);

return std::error_code();
}

const DefinedAtom *makeTLVPEntry(const Atom *target) {
auto pos = _targetToTLVP.find(target);

if (pos != _targetToTLVP.end())
return pos->second;

TLVPEntryAtom *tlvpEntry = new (_file.allocator())
TLVPEntryAtom(_file, _ctx.is64Bit(), target->name());
_targetToTLVP[target] = tlvpEntry;
const ArchHandler::ReferenceInfo &nlInfo =
_archHandler.stubInfo().nonLazyPointerReferenceToBinder;
tlvpEntry->addReference(Reference::KindNamespace::mach_o, nlInfo.arch,
nlInfo.kind, 0, target, 0);
return tlvpEntry;
}

const MachOLinkingContext &_ctx;
mach_o::ArchHandler &_archHandler;
MachOFile _file;
llvm::DenseMap<const Atom*, const TLVPEntryAtom*> _targetToTLVP;
};

void addTLVPass(PassManager &pm, const MachOLinkingContext &ctx) {
assert(ctx.needsTLVPass());
pm.add(llvm::make_unique<TLVPass>(ctx));
}


} // end namesapce mach_o
} // end namesapce lld
100 changes: 100 additions & 0 deletions lld/test/mach-o/parse-tlv-relocs-x86-64.yaml
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# RUN: lld -flavor darwin -arch x86_64 -r -print_atoms %s -o %t | FileCheck %s \
# RUN: && lld -flavor darwin -arch x86_64 -r -print_atoms %t -o %t2 | FileCheck %s
#
# Test parsing of x86_64 tlv relocations.

--- !mach-o
arch: x86_64
file-type: MH_OBJECT
flags: [ MH_SUBSECTIONS_VIA_SYMBOLS ]
compat-version: 0.0
current-version: 0.0
has-UUID: false
OS: unknown
sections:
- segment: __TEXT
section: __text
type: S_REGULAR
attributes: [ S_ATTR_PURE_INSTRUCTIONS, S_ATTR_SOME_INSTRUCTIONS ]
alignment: 16
address: 0x0000000000000000
content: [ 0x55, 0x48, 0x89, 0xE5, 0x48, 0x8B, 0x3D, 0x00,
0x00, 0x00, 0x00, 0xFF, 0x17, 0x8B, 0x00, 0x5D,
0xC3 ]
relocations:
- offset: 0x00000007
type: X86_64_RELOC_TLV
length: 2
pc-rel: true
extern: true
symbol: 2
- segment: __DATA
section: __thread_data
type: S_THREAD_LOCAL_REGULAR
attributes: [ ]
alignment: 4
address: 0x0000000000000014
content: [ 0x07, 0x00, 0x00, 0x00 ]
- segment: __DATA
section: __thread_vars
type: S_THREAD_LOCAL_VARIABLES
attributes: [ ]
address: 0x0000000000000018
content: [ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ]
relocations:
- offset: 0x00000010
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: true
symbol: 0
- offset: 0x00000000
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: true
symbol: 3
local-symbols:
- name: '_x$tlv$init'
type: N_SECT
sect: 2
value: 0x0000000000000014
global-symbols:
- name: _main
type: N_SECT
scope: [ N_EXT ]
sect: 1
value: 0x0000000000000000
- name: _x
type: N_SECT
scope: [ N_EXT ]
sect: 3
value: 0x0000000000000018
undefined-symbols:
- name: __tlv_bootstrap
type: N_UNDF
scope: [ N_EXT ]
value: 0x0000000000000000
page-size: 0x00000000
...

# CHECK: - name: _x
# CHECK-NEXT: scope: global
# CHECK-NEXT: type: tlv-thunk
# CHECK-NOT: - name:
# CHECK: references:
# CHECK-NEXT: - kind: pointer64
# CHECK-NEXT: offset: 0
# CHECK-NEXT: target: __tlv_bootstrap
# CHECK-NEXT: - kind: tlvInitSectionOffset
# CHECK-NEXT: offset: 16
# CHECK-NEXT: target: '_x$tlv$init'
# CHECK: - name: _main
# CHECK-NOT: - name:
# CHECK-NEXT: scope: global
# CHECK: references:
# CHECK-NEXT: - kind: ripRel32Tlv
# CHECK-NEXT: offset: 7
# CHECK-NEXT: target: _x
133 changes: 133 additions & 0 deletions lld/test/mach-o/run-tlv-pass-x86-64.yaml
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# RUN: lld -flavor darwin -macosx_version_min 10.7 -arch x86_64 -print_atoms %s -o %t | FileCheck %s
# RUN: not lld -flavor darwin -macosx_version_min 10.6 -arch x86_64 -o %t %s 2> %t2
# RUN: FileCheck < %t2 %s --check-prefix=CHECK-ERROR
#
# Test parsing of x86_64 tlv relocations.

--- !mach-o
arch: x86_64
file-type: MH_OBJECT
flags: [ MH_SUBSECTIONS_VIA_SYMBOLS ]
compat-version: 0.0
current-version: 0.0
has-UUID: false
OS: unknown
sections:
- segment: __TEXT
section: __text
type: S_REGULAR
attributes: [ S_ATTR_PURE_INSTRUCTIONS, S_ATTR_SOME_INSTRUCTIONS ]
alignment: 16
address: 0x0000000000000000
content: [ 0x55, 0x48, 0x89, 0xE5, 0x48, 0x8B, 0x3D, 0x00,
0x00, 0x00, 0x00, 0xFF, 0x17, 0x8B, 0x00, 0x5D,
0xC3 ]
relocations:
- offset: 0x00000007
type: X86_64_RELOC_TLV
length: 2
pc-rel: true
extern: true
symbol: 2
- segment: __DATA
section: __thread_data
type: S_THREAD_LOCAL_REGULAR
attributes: [ ]
alignment: 4
address: 0x0000000000000014
content: [ 0x07, 0x00, 0x00, 0x00 ]
- segment: __DATA
section: __thread_vars
type: S_THREAD_LOCAL_VARIABLES
attributes: [ ]
address: 0x0000000000000018
content: [ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ]
relocations:
- offset: 0x00000010
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: true
symbol: 0
- offset: 0x00000000
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: true
symbol: 3
- segment: __DATA
section: __dummy
type: S_REGULAR
attributes: [ ]
alignment: 8
address: 0x00000000000000C0
content: [ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ]
local-symbols:
- name: '_x$tlv$init'
type: N_SECT
sect: 2
value: 0x0000000000000014
global-symbols:
- name: _main
type: N_SECT
scope: [ N_EXT ]
sect: 1
value: 0x0000000000000000
- name: _x
type: N_SECT
scope: [ N_EXT ]
sect: 3
value: 0x0000000000000018
- name: '__tlv_bootstrap'
type: N_SECT
scope: [ N_EXT ]
sect: 4
value: 0x00000000000000C0
- name: 'dyld_stub_binder'
type: N_SECT
scope: [ N_EXT ]
sect: 4
value: 0x00000000000000C8
- name: 'start'
type: N_SECT
scope: [ N_EXT ]
sect: 4
value: 0x00000000000000D0
page-size: 0x00000000
...

# CHECK: - name: _x
# CHECK-NEXT: scope: global
# CHECK-NEXT: type: tlv-thunk
# CHECK-NOT: - name:
# CHECK: references:
# CHECK-NEXT: - kind: pointer64
# CHECK-NEXT: offset: 0
# CHECK-NEXT: target: __tlv_bootstrap
# CHECK-NEXT: - kind: tlvInitSectionOffset
# CHECK-NEXT: offset: 16
# CHECK-NEXT: target: '_x$tlv$init'
# CHECK-NEXT: - name: '_x$tlv$init'
# CHECK-NEXT: type: tlv-data
# CHECK: - name: _main
# CHECK-NOT: - name:
# CHECK: references:
# CHECK-NEXT: - kind: ripRel32
# CHECK-NEXT: offset: 7
# CHECK-NEXT: target: L[[ID:[0-9]+]]
# CHECK: - ref-name: L[[ID]]
# CHECK-NEXT: scope: hidden
# CHECK-NEXT: type: tlv-initializer-ptr
# CHECK-NEXT: content: [ 00, 00, 00, 00, 00, 00, 00, 00 ]
# CHECK-NEXT: alignment: 8
# CHECK-NEXT: permissions: rw-
# CHECK-NEXT: references:
# CHECK-NEXT: - kind: pointer64
# CHECK-NEXT: offset: 0
# CHECK-NEXT: target: _x

# CHECK-ERROR: targeted OS version does not support use of thread local variables in _main for architecture x86_64