forked from OSchip/llvm-project
[ARM] Add mapping symbols to veneers
This required splitting up veneer atoms into pieces, where every piece is paired with mapping atom of the corresponding type. llvm-svn: 234473
This commit is contained in:
Denis Protivensky
parent
2aa8c8fd17
commit
6b3a33ff00
|
|
@ -32,17 +32,21 @@ namespace {
|
|||
// ARM B/BL instructions of static relocation veneer.
|
||||
// TODO: consider different instruction set for archs below ARMv5
|
||||
// (one as for Thumb may be used though it's less optimal).
|
||||
static const uint8_t Veneer_ARM_B_BL_StaticAtomContent[8] = {
|
||||
0x04, 0xf0, 0x1f, 0xe5, // ldr pc, [pc, #-4]
|
||||
static const uint8_t Veneer_ARM_B_BL_Static_a_AtomContent[4] = {
|
||||
0x04, 0xf0, 0x1f, 0xe5 // ldr pc, [pc, #-4]
|
||||
};
|
||||
static const uint8_t Veneer_ARM_B_BL_Static_d_AtomContent[4] = {
|
||||
0x00, 0x00, 0x00, 0x00 // <target_symbol_address>
|
||||
};
|
||||
|
||||
// Thumb B/BL instructions of static relocation veneer.
|
||||
// TODO: consider different instruction set for archs above ARMv5
|
||||
// (one as for ARM may be used since it's more optimal).
|
||||
static const uint8_t Veneer_THM_B_BL_StaticAtomContent[8] = {
|
||||
static const uint8_t Veneer_THM_B_BL_Static_t_AtomContent[4] = {
|
||||
0x78, 0x47, // bx pc
|
||||
0x00, 0x00, // nop
|
||||
0x00, 0x00 // nop
|
||||
};
|
||||
static const uint8_t Veneer_THM_B_BL_Static_a_AtomContent[4] = {
|
||||
0xfe, 0xff, 0xff, 0xea // b <target_symbol_address>
|
||||
};
|
||||
|
||||
|
|
@ -62,7 +66,6 @@ static const uint8_t ARMPltVeneerAtomContent[4] = {
|
|||
0x00, 0x00 // nop
|
||||
};
|
||||
|
||||
#ifdef NDEBUG
|
||||
// Determine proper names for mapping symbols.
|
||||
static std::string getMappingAtomName(DefinedAtom::CodeModel model,
|
||||
const std::string &part) {
|
||||
|
|
@ -77,15 +80,14 @@ static std::string getMappingAtomName(DefinedAtom::CodeModel model,
|
|||
llvm_unreachable("Wrong code model of mapping atom");
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
/// \brief Atoms that hold veneer code.
|
||||
class VeneerAtom : public SimpleELFDefinedAtom {
|
||||
StringRef _section;
|
||||
|
||||
public:
|
||||
VeneerAtom(const File &f, StringRef secName)
|
||||
: SimpleELFDefinedAtom(f), _section(secName) {}
|
||||
VeneerAtom(const File &f, StringRef secName, const std::string &name = "")
|
||||
: SimpleELFDefinedAtom(f), _section(secName), _name(name) {}
|
||||
|
||||
Scope scope() const override { return DefinedAtom::scopeTranslationUnit; }
|
||||
|
||||
|
|
@ -106,37 +108,79 @@ public:
|
|||
Alignment alignment() const override { return 4; }
|
||||
|
||||
StringRef name() const override { return _name; }
|
||||
|
||||
private:
|
||||
std::string _name;
|
||||
};
|
||||
|
||||
/// \brief Atoms that hold veneer for statically relocated
|
||||
/// ARM B/BL instructions.
|
||||
class Veneer_ARM_B_BL_StaticAtom : public VeneerAtom {
|
||||
class Veneer_ARM_B_BL_Static_a_Atom : public VeneerAtom {
|
||||
public:
|
||||
Veneer_ARM_B_BL_StaticAtom(const File &f, StringRef secName)
|
||||
Veneer_ARM_B_BL_Static_a_Atom(const File &f, StringRef secName,
|
||||
const std::string &name)
|
||||
: VeneerAtom(f, secName, name) {}
|
||||
|
||||
ArrayRef<uint8_t> rawContent() const override {
|
||||
return llvm::makeArrayRef(Veneer_ARM_B_BL_Static_a_AtomContent);
|
||||
}
|
||||
};
|
||||
|
||||
class Veneer_ARM_B_BL_Static_d_Atom : public VeneerAtom {
|
||||
public:
|
||||
Veneer_ARM_B_BL_Static_d_Atom(const File &f, StringRef secName)
|
||||
: VeneerAtom(f, secName) {}
|
||||
|
||||
ArrayRef<uint8_t> rawContent() const override {
|
||||
return llvm::makeArrayRef(Veneer_ARM_B_BL_StaticAtomContent);
|
||||
return llvm::makeArrayRef(Veneer_ARM_B_BL_Static_d_AtomContent);
|
||||
}
|
||||
};
|
||||
|
||||
/// \brief Atoms that hold veneer for statically relocated
|
||||
/// Thumb B/BL instructions.
|
||||
class Veneer_THM_B_BL_StaticAtom : public VeneerAtom {
|
||||
class Veneer_THM_B_BL_Static_t_Atom : public VeneerAtom {
|
||||
public:
|
||||
Veneer_THM_B_BL_StaticAtom(const File &f, StringRef secName)
|
||||
: VeneerAtom(f, secName) {}
|
||||
Veneer_THM_B_BL_Static_t_Atom(const File &f, StringRef secName,
|
||||
const std::string &name)
|
||||
: VeneerAtom(f, secName, name) {}
|
||||
|
||||
DefinedAtom::CodeModel codeModel() const override {
|
||||
return DefinedAtom::codeARMThumb;
|
||||
}
|
||||
|
||||
ArrayRef<uint8_t> rawContent() const override {
|
||||
return llvm::makeArrayRef(Veneer_THM_B_BL_StaticAtomContent);
|
||||
return llvm::makeArrayRef(Veneer_THM_B_BL_Static_t_AtomContent);
|
||||
}
|
||||
};
|
||||
|
||||
class Veneer_THM_B_BL_Static_a_Atom : public VeneerAtom {
|
||||
public:
|
||||
Veneer_THM_B_BL_Static_a_Atom(const File &f, StringRef secName)
|
||||
: VeneerAtom(f, secName) {}
|
||||
|
||||
ArrayRef<uint8_t> rawContent() const override {
|
||||
return llvm::makeArrayRef(Veneer_THM_B_BL_Static_a_AtomContent);
|
||||
}
|
||||
};
|
||||
|
||||
template <DefinedAtom::CodeModel Model>
|
||||
class ARMVeneerMappingAtom : public VeneerAtom {
|
||||
public:
|
||||
ARMVeneerMappingAtom(const File &f, StringRef secName, StringRef name)
|
||||
: VeneerAtom(f, secName, getMappingAtomName(Model, name)) {
|
||||
static_assert((Model == DefinedAtom::codeARM_a ||
|
||||
Model == DefinedAtom::codeARM_d ||
|
||||
Model == DefinedAtom::codeARM_t),
|
||||
"Only mapping atom types are allowed");
|
||||
}
|
||||
|
||||
uint64_t size() const override { return 0; }
|
||||
|
||||
ArrayRef<uint8_t> rawContent() const override { return ArrayRef<uint8_t>(); }
|
||||
|
||||
DefinedAtom::CodeModel codeModel() const override { return Model; }
|
||||
};
|
||||
|
||||
/// \brief Atoms that are used by ARM dynamic linking
|
||||
class ARMGOTAtom : public GOTAtom {
|
||||
public:
|
||||
|
|
@ -353,6 +397,20 @@ protected:
|
|||
return g;
|
||||
}
|
||||
|
||||
/// \brief Add veneer with mapping symbol.
|
||||
template <DefinedAtom::CodeModel Model>
|
||||
void addVeneerWithMapping(const DefinedAtom *da, VeneerAtom *va,
|
||||
const std::string &name) {
|
||||
assert(_veneerAtoms.lookup(da).empty() &&
|
||||
"Veneer or mapping already exists");
|
||||
auto *ma = new (_file._alloc)
|
||||
ARMVeneerMappingAtom<Model>(_file, va->customSectionName(), name);
|
||||
|
||||
// Fake reference to show connection between the mapping symbol and veneer.
|
||||
va->addReferenceELF_ARM(R_ARM_NONE, 0, ma, 0);
|
||||
_veneerAtoms[da] = VeneerWithMapping(va, ma);
|
||||
}
|
||||
|
||||
/// \brief get a veneer for a PLT entry.
|
||||
const PLTAtom *getPLTVeneer(const DefinedAtom *da, PLTAtom *pa,
|
||||
StringRef source) {
|
||||
|
|
@ -539,8 +597,12 @@ public:
|
|||
}
|
||||
for (auto &veneerKV : _veneerAtoms) {
|
||||
auto &veneer = veneerKV.second;
|
||||
veneer->setOrdinal(ordinal++);
|
||||
mf->addAtom(*veneer);
|
||||
auto *m = veneer._mapping;
|
||||
m->setOrdinal(ordinal++);
|
||||
mf->addAtom(*m);
|
||||
auto *v = veneer._veneer;
|
||||
v->setOrdinal(ordinal++);
|
||||
mf->addAtom(*v);
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -568,7 +630,20 @@ protected:
|
|||
llvm::MapVector<const Atom *, PLTWithVeneer> _pltAtoms;
|
||||
|
||||
/// \brief Map Atoms to their veneers.
|
||||
llvm::MapVector<const Atom *, VeneerAtom *> _veneerAtoms;
|
||||
struct VeneerWithMapping {
|
||||
VeneerWithMapping(VeneerAtom *v = nullptr, VeneerAtom *m = nullptr)
|
||||
: _veneer(v), _mapping(m) {}
|
||||
|
||||
bool empty() const {
|
||||
assert(((bool)_veneer == (bool)_mapping) &&
|
||||
"Mapping symbol should always be paired with veneer");
|
||||
return !_veneer && !_mapping;
|
||||
}
|
||||
|
||||
VeneerAtom *_veneer;
|
||||
VeneerAtom *_mapping;
|
||||
};
|
||||
llvm::MapVector<const Atom *, VeneerWithMapping> _veneerAtoms;
|
||||
|
||||
/// \brief GOT entry that is always 0. Used for undefined weaks.
|
||||
GOTAtom *_null = nullptr;
|
||||
|
|
@ -589,33 +664,47 @@ public:
|
|||
/// \brief Get the veneer for ARM B/BL instructions.
|
||||
const VeneerAtom *getVeneer_ARM_B_BL(const DefinedAtom *da,
|
||||
StringRef secName) {
|
||||
if (auto veneer = _veneerAtoms.lookup(da))
|
||||
return veneer;
|
||||
auto v = new (_file._alloc) Veneer_ARM_B_BL_StaticAtom(_file, secName);
|
||||
v->addReferenceELF_ARM(R_ARM_ABS32, 4, da, 0);
|
||||
auto veneer = _veneerAtoms.lookup(da);
|
||||
if (!veneer.empty())
|
||||
return veneer._veneer;
|
||||
|
||||
v->_name = "__";
|
||||
v->_name += da->name();
|
||||
v->_name += "_from_arm";
|
||||
std::string name = "__";
|
||||
name += da->name();
|
||||
name += "_from_arm";
|
||||
// Create parts of veneer with mapping symbols.
|
||||
auto v_a = new (_file._alloc) Veneer_ARM_B_BL_Static_a_Atom(_file, secName, name);
|
||||
addVeneerWithMapping<DefinedAtom::codeARM_a>(da, v_a, name);
|
||||
auto v_d = new (_file._alloc) Veneer_ARM_B_BL_Static_d_Atom(_file, secName);
|
||||
addVeneerWithMapping<DefinedAtom::codeARM_d>(v_a, v_d, name);
|
||||
|
||||
_veneerAtoms[da] = v;
|
||||
return v;
|
||||
// Fake reference to show connection between parts of veneer.
|
||||
v_a->addReferenceELF_ARM(R_ARM_NONE, 0, v_d, 0);
|
||||
// Real reference to fixup.
|
||||
v_d->addReferenceELF_ARM(R_ARM_ABS32, 0, da, 0);
|
||||
return v_a;
|
||||
}
|
||||
|
||||
/// \brief Get the veneer for Thumb B/BL instructions.
|
||||
const VeneerAtom *getVeneer_THM_B_BL(const DefinedAtom *da,
|
||||
StringRef secName) {
|
||||
if (auto veneer = _veneerAtoms.lookup(da))
|
||||
return veneer;
|
||||
auto v = new (_file._alloc) Veneer_THM_B_BL_StaticAtom(_file, secName);
|
||||
v->addReferenceELF_ARM(R_ARM_JUMP24, 4, da, 0);
|
||||
auto veneer = _veneerAtoms.lookup(da);
|
||||
if (!veneer.empty())
|
||||
return veneer._veneer;
|
||||
|
||||
v->_name = "__";
|
||||
v->_name += da->name();
|
||||
v->_name += "_from_thumb";
|
||||
std::string name = "__";
|
||||
name += da->name();
|
||||
name += "_from_thumb";
|
||||
// Create parts of veneer with mapping symbols.
|
||||
auto v_t = new (_file._alloc) Veneer_THM_B_BL_Static_t_Atom(_file, secName, name);
|
||||
addVeneerWithMapping<DefinedAtom::codeARM_t>(da, v_t, name);
|
||||
auto v_a = new (_file._alloc) Veneer_THM_B_BL_Static_a_Atom(_file, secName);
|
||||
addVeneerWithMapping<DefinedAtom::codeARM_a>(v_t, v_a, name);
|
||||
|
||||
_veneerAtoms[da] = v;
|
||||
return v;
|
||||
// Fake reference to show connection between parts of veneer.
|
||||
v_t->addReferenceELF_ARM(R_ARM_NONE, 0, v_a, 0);
|
||||
// Real reference to fixup.
|
||||
v_a->addReferenceELF_ARM(R_ARM_JUMP24, 0, da, 0);
|
||||
return v_t;
|
||||
}
|
||||
|
||||
/// \brief Create a GOT entry for R_ARM_TLS_TPOFF32 reloc.
|
||||
|
|
|
|||
|
|
@ -0,0 +1,94 @@
|
|||
# Check that mapping symbols are properly generated for veneers.
|
||||
|
||||
# RUN: yaml2obj -format=elf -docnum 1 %s > %t-arm.o
|
||||
# RUN: yaml2obj -format=elf -docnum 2 %s > %t-thm.o
|
||||
# RUN: lld -flavor gnu -target arm-linux-gnu --defsym=main=fa \
|
||||
# RUN: -Bstatic --noinhibit-exec %t-arm.o %t-thm.o -o %t
|
||||
# RUN: llvm-readobj -symbols %t | FileCheck %s
|
||||
|
||||
# CHECK: Name: $a.__ft_from_arm
|
||||
# CHECK: Name: $d.__ft_from_arm
|
||||
# CHECK: Name: $t.__fa_from_thumb
|
||||
# CHECK: Name: $a.__fa_from_thumb
|
||||
|
||||
# arm.o
|
||||
---
|
||||
FileHeader:
|
||||
Class: ELFCLASS32
|
||||
Data: ELFDATA2LSB
|
||||
Type: ET_REL
|
||||
Machine: EM_ARM
|
||||
Flags: [ EF_ARM_EABI_VER5 ]
|
||||
Sections:
|
||||
- Name: .text
|
||||
Type: SHT_PROGBITS
|
||||
Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
|
||||
AddressAlign: 0x0000000000000004
|
||||
Content: 00482DE904B08DE2FEFFFFEA0030A0E10300A0E10088BDE8
|
||||
- Name: .rel.text
|
||||
Type: SHT_REL
|
||||
Link: .symtab
|
||||
AddressAlign: 0x0000000000000004
|
||||
Info: .text
|
||||
Relocations:
|
||||
- Offset: 0x0000000000000008
|
||||
Symbol: ft
|
||||
Type: R_ARM_JUMP24
|
||||
- Name: .data
|
||||
Type: SHT_PROGBITS
|
||||
Flags: [ SHF_WRITE, SHF_ALLOC ]
|
||||
AddressAlign: 0x0000000000000001
|
||||
Content: ''
|
||||
- Name: .bss
|
||||
Type: SHT_NOBITS
|
||||
Flags: [ SHF_WRITE, SHF_ALLOC ]
|
||||
AddressAlign: 0x0000000000000001
|
||||
Content: ''
|
||||
Symbols:
|
||||
Global:
|
||||
- Name: fa
|
||||
Type: STT_FUNC
|
||||
Section: .text
|
||||
- Name: ft
|
||||
|
||||
# thm.o
|
||||
---
|
||||
FileHeader:
|
||||
Class: ELFCLASS32
|
||||
Data: ELFDATA2LSB
|
||||
Type: ET_REL
|
||||
Machine: EM_ARM
|
||||
Flags: [ EF_ARM_EABI_VER5 ]
|
||||
Sections:
|
||||
- Name: .text
|
||||
Type: SHT_PROGBITS
|
||||
Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
|
||||
AddressAlign: 0x0000000000000004
|
||||
Content: 80B500AFFFF7FEBF0346184680BD00BF
|
||||
- Name: .rel.text
|
||||
Type: SHT_REL
|
||||
Link: .symtab
|
||||
AddressAlign: 0x0000000000000004
|
||||
Info: .text
|
||||
Relocations:
|
||||
- Offset: 0x0000000000000004
|
||||
Symbol: fa
|
||||
Type: R_ARM_THM_JUMP24
|
||||
- Name: .data
|
||||
Type: SHT_PROGBITS
|
||||
Flags: [ SHF_WRITE, SHF_ALLOC ]
|
||||
AddressAlign: 0x0000000000000001
|
||||
Content: ''
|
||||
- Name: .bss
|
||||
Type: SHT_NOBITS
|
||||
Flags: [ SHF_WRITE, SHF_ALLOC ]
|
||||
AddressAlign: 0x0000000000000001
|
||||
Content: ''
|
||||
Symbols:
|
||||
Global:
|
||||
- Name: ft
|
||||
Type: STT_FUNC
|
||||
Section: .text
|
||||
Value: 0x0000000000000001
|
||||
- Name: fa
|
||||
...
|
||||
Loading…
Reference in New Issue