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[lld][MachO] Add support for x86-64 negDelta64 references and fix negDelta32. 

These references are used to implement MachO/x64-64 subtractor relocations
where the minuend is being fixed up, rather than the subtrahend. The 64-bit
version was not previously supported, the 32-bit version was partially
implemented but contained bugs not caught by existing test cases. This
patch fixes both functionality and test coverage.

llvm-svn: 273759
This commit is contained in:
Lang Hames 2016-06-25 00:29:54 +00:00
parent c79ad577fb
commit 3b3b4d792f
3 changed files with 169 additions and 100 deletions
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96
lld/lib/ReaderWriter/MachO/ArchHandler_x86_64.cpp
View File

@ -203,6 +203,7 @@ private:
delta32, /// ex: .long _foo - .
delta64Anon, /// ex: .quad L1 - .
delta32Anon, /// ex: .long L1 - .
negDelta64, /// ex: .quad . - _foo
negDelta32, /// ex: .long . - _foo
// Kinds introduced by Passes:
@ -224,8 +225,6 @@ private:
};
Reference::KindValue kindFromReloc(const normalized::Relocation &reloc);
Reference::KindValue kindFromRelocPair(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2);
void applyFixupFinal(const Reference &ref, uint8_t *location,
uint64_t fixupAddress, uint64_t targetAddress,
@ -254,6 +253,7 @@ const Registry::KindStrings ArchHandler_x86_64::_sKindStrings[] = {
LLD_KIND_STRING_ENTRY(pointer64), LLD_KIND_STRING_ENTRY(pointer64Anon),
LLD_KIND_STRING_ENTRY(delta32), LLD_KIND_STRING_ENTRY(delta64),
LLD_KIND_STRING_ENTRY(delta32Anon), LLD_KIND_STRING_ENTRY(delta64Anon),
LLD_KIND_STRING_ENTRY(negDelta64),
LLD_KIND_STRING_ENTRY(negDelta32),
LLD_KIND_STRING_ENTRY(imageOffset), LLD_KIND_STRING_ENTRY(imageOffsetGot),
LLD_KIND_STRING_ENTRY(unwindFDEToFunction),
@ -438,27 +438,6 @@ ArchHandler_x86_64::getReferenceInfo(const Relocation &reloc,
}
}
Reference::KindValue
ArchHandler_x86_64::kindFromRelocPair(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2) {
switch(relocPattern(reloc1) << 16 | relocPattern(reloc2)) {
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength8) << 16 |
X86_64_RELOC_UNSIGNED | rExtern | rLength8):
return delta64;
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength4) << 16 |
X86_64_RELOC_UNSIGNED | rExtern | rLength4):
return delta32;
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength8) << 16 |
X86_64_RELOC_UNSIGNED | rLength8):
return delta64Anon;
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength4) << 16 |
X86_64_RELOC_UNSIGNED | rLength4):
return delta32Anon;
default:
llvm_unreachable("bad reloc pairs");
}
}
llvm::Error
ArchHandler_x86_64::getPairReferenceInfo(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2,
@ -471,35 +450,61 @@ ArchHandler_x86_64::getPairReferenceInfo(const normalized::Relocation &reloc1,
Reference::KindValue *kind,
const lld::Atom **target,
Reference::Addend *addend) {
*kind = kindFromRelocPair(reloc1, reloc2);
if (*kind == invalid)
return llvm::make_error<GenericError>("unknown pair");
const uint8_t *fixupContent = &inAtom->rawContent()[offsetInAtom];
uint64_t targetAddress;
const lld::Atom *fromTarget;
if (auto ec = atomFromSymbolIndex(reloc1.symbol, &fromTarget))
return ec;
if (fromTarget != inAtom)
return llvm::make_error<GenericError>("pointer diff not in base atom");
switch (*kind) {
case delta64:
switch(relocPattern(reloc1) << 16 | relocPattern(reloc2)) {
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength8) << 16 |
X86_64_RELOC_UNSIGNED | rExtern | rLength8): {
if (auto ec = atomFromSymbolIndex(reloc2.symbol, target))
return ec;
*addend = (int64_t)*(const little64_t *)fixupContent + offsetInAtom;
uint64_t encodedAddend = (int64_t)*(const little64_t *)fixupContent;
if (inAtom == fromTarget) {
*kind = delta64;
*addend = encodedAddend + offsetInAtom;
} else if (inAtom == *target) {
*kind = negDelta64;
*addend = encodedAddend - offsetInAtom;
*target = fromTarget;
} else
return llvm::make_error<GenericError>("Invalid pointer diff");
return llvm::Error();
case delta32:
}
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength4) << 16 |
X86_64_RELOC_UNSIGNED | rExtern | rLength4): {
if (auto ec = atomFromSymbolIndex(reloc2.symbol, target))
return ec;
*addend = (int32_t)*(const little32_t *)fixupContent + offsetInAtom;
uint32_t encodedAddend = (int32_t)*(const little32_t *)fixupContent;
if (inAtom == fromTarget) {
*kind = delta32;
*addend = encodedAddend + offsetInAtom;
} else if (inAtom == *target) {
*kind = negDelta32;
*addend = encodedAddend - offsetInAtom;
*target = fromTarget;
} else
return llvm::make_error<GenericError>("Invalid pointer diff");
return llvm::Error();
case delta64Anon:
}
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength8) << 16 |
X86_64_RELOC_UNSIGNED | rLength8):
if (fromTarget != inAtom)
return llvm::make_error<GenericError>("pointer diff not in base atom");
*kind = delta64Anon;
targetAddress = offsetInAtom + (int64_t)*(const little64_t *)fixupContent;
return atomFromAddress(reloc2.symbol, targetAddress, target, addend);
case delta32Anon:
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength4) << 16 |
X86_64_RELOC_UNSIGNED | rLength4):
if (fromTarget != inAtom)
return llvm::make_error<GenericError>("pointer diff not in base atom");
*kind = delta32Anon;
targetAddress = offsetInAtom + (int32_t)*(const little32_t *)fixupContent;
return atomFromAddress(reloc2.symbol, targetAddress, target, addend);
default:
llvm_unreachable("bad reloc pair kind");
return llvm::make_error<GenericError>("unknown pair");
}
}
@ -583,6 +588,9 @@ void ArchHandler_x86_64::applyFixupFinal(
loc[-2] = 0x8D;
*loc32 = targetAddress - (fixupAddress + 4) + ref.addend();
return;
case negDelta64:
*loc64 = fixupAddress - targetAddress + ref.addend();
return;
case negDelta32:
*loc32 = fixupAddress - targetAddress + ref.addend();
return;
@ -687,8 +695,11 @@ void ArchHandler_x86_64::applyFixupRelocatable(const Reference &ref,
// Then we want to encode the value (Ltarget + addend) - (LFixup - _base)
*loc64 = (targetAddress + ref.addend()) - (fixupAddress - inAtomAddress);
return;
case negDelta64:
*loc64 = ref.addend() + fixupAddress - inAtomAddress;
return;
case negDelta32:
*loc32 = fixupAddress - targetAddress + ref.addend();
*loc32 = ref.addend() + fixupAddress - inAtomAddress;
return;
case ripRel32GotLoadNowLea:
llvm_unreachable("ripRel32GotLoadNowLea implies GOT pass was run");
@ -808,7 +819,18 @@ void ArchHandler_x86_64::appendSectionRelocations(
return;
case unwindFDEToFunction:
case unwindInfoToEhFrame:
return;
case negDelta32:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_SUBTRACTOR | rExtern | rLength4 );
appendReloc(relocs, sectionOffset, symbolIndexForAtom(atom), 0,
X86_64_RELOC_UNSIGNED | rExtern | rLength4 );
return;
case negDelta64:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_SUBTRACTOR | rExtern | rLength8 );
appendReloc(relocs, sectionOffset, symbolIndexForAtom(atom), 0,
X86_64_RELOC_UNSIGNED | rExtern | rLength8 );
return;
case ripRel32GotLoadNowLea:
llvm_unreachable("ripRel32GotLoadNowLea implies GOT pass was run");

2
lld/lib/ReaderWriter/MachO/File.h
View File

@ -247,6 +247,8 @@ private:
offAndAtom.atom = atom;
_sectionAtoms[inSection].push_back(offAndAtom);
addAtom(*atom);
// llvm::dbgs() << "In " << inSection->sectionName << ": Added "
// << atom << " (" << atom->name() << ")\n";
}
typedef llvm::DenseMap<const normalized::Section *,

167
lld/test/mach-o/parse-data-relocs-x86_64.yaml
View File

@ -76,6 +76,13 @@ sections:
# Note the addend here is -16 because that is the offset from here back
# to _d.
0xF0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
# .quad . - _foo
# This is the pair X86_64_RELOC_SUBTRACTOR and X86_64_RELOC_UNSIGNED.
# The subtractor references _d which is the first nonlocal label in this
# section. The unsigned references _foo.
# Note the addend here is -16 because that is the offset from here back
# to _d.
0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
# .quad L1
# This is a X86_64_RELOC_UNSIGNED without extern set.
# In this case, we encode the section number for L1 in the relocation, and
@ -95,49 +102,92 @@ sections:
# section. The unsigned references _foo.
# Note the addend here is -40 because that is the offset from here back
# to _d.
0xD8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xD0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
# .quad _foo + 4 - .
# This is the pair X86_64_RELOC_SUBTRACTOR and X86_64_RELOC_UNSIGNED.
# The subtractor references _d which is the first nonlocal label in this
# section. The unsigned references _foo.
# Note the addend here is -44. It would have been -48 because that
# Note the addend here is -52. It would have been -56 because that
# would take us from the address of this relocation back to _d. But as
# we also add 4 for the offset, we get -44.
0xD4, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
# we also add 4 for the offset, we get -52.
0xCC, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
# .quad L1 - .
# This is the pair X86_64_RELOC_SUBTRACTOR and X86_64_RELOC_UNSIGNED.
# The subtractor references _d which is the first nonlocal label in this
# section. The unsigned does not have extern set, so the relocation
# number is the section number for L1.
# Note the addend here is -54. Of that, -56 would be the offset from
# Note the addend here is -62. Of that, -64 would be the offset from
# this location from _d. The remaining 2 is the absolute address
# of L1.
0xCA, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xC2, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
# .long _foo - .
# This is the pair X86_64_RELOC_SUBTRACTOR and X86_64_RELOC_UNSIGNED.
# The subtractor references _d which is the first nonlocal label in this
# section. The unsigned references _foo.
# Note the addend here is -64 because that is the offset from here back
# Note the addend here is -72 because that is the offset from here back
# to _d.
0xC0, 0xFF, 0xFF, 0xFF,
0xB8, 0xFF, 0xFF, 0xFF,
# .long . - _foo
# This is the pair X86_64_RELOC_SUBTRACTOR and X86_64_RELOC_UNSIGNED.
# The subtractor references _d which is the first nonlocal label in this
# section. The unsigned references _foo.
# Note the addend here is -76 because that is the offset from here back
# to _d.
0xB4, 0xFF, 0xFF, 0xFF,
# .long _foo + 4 - .
# This is the pair X86_64_RELOC_SUBTRACTOR and X86_64_RELOC_UNSIGNED.
# The subtractor references _d which is the first nonlocal label in this
# section. The unsigned references _foo.
# Note the addend here is -64. It would have been -68 because that
# Note the addend here is -76. It would have been -80 because that
# would take us from the address of this relocation back to _d. But as
# we also add 4 for the offset, we get -64.
0xC0, 0xFF, 0xFF, 0xFF,
# we also add 4 for the offset, we get -76.
0xB4, 0xFF, 0xFF, 0xFF,
# .long L1 - .
# This is the pair X86_64_RELOC_SUBTRACTOR and X86_64_RELOC_UNSIGNED.
# The subtractor references _d which is the first nonlocal label in this
# section. The unsigned does not have extern set, so the relocation
# number is the section number for L1.
# Note the addend here is -70. Of that, -72 would be the offset from
# Note the addend here is -82. Of that, -84 would be the offset from
# this location from _d. The remaining 2 is the absolute address
# of L1.
0xBA, 0xFF, 0xFF, 0xFF ]
0xAE, 0xFF, 0xFF, 0xFF ]
relocations:
- offset: 0x00000054
type: X86_64_RELOC_SUBTRACTOR
length: 2
pc-rel: false
extern: true
symbol: 2
- offset: 0x00000054
type: X86_64_RELOC_UNSIGNED
length: 2
pc-rel: false
extern: false
symbol: 2
- offset: 0x00000050
type: X86_64_RELOC_SUBTRACTOR
length: 2
pc-rel: false
extern: true
symbol: 2
- offset: 0x00000050
type: X86_64_RELOC_UNSIGNED
length: 2
pc-rel: false
extern: true
symbol: 0
- offset: 0x0000004C
type: X86_64_RELOC_SUBTRACTOR
length: 2
pc-rel: false
extern: true
symbol: 0
- offset: 0x0000004C
type: X86_64_RELOC_UNSIGNED
length: 2
pc-rel: false
extern: true
symbol: 2
- offset: 0x00000048
type: X86_64_RELOC_SUBTRACTOR
length: 2
@ -148,32 +198,20 @@ sections:
type: X86_64_RELOC_UNSIGNED
length: 2
pc-rel: false
extern: true
symbol: 0
- offset: 0x00000040
type: X86_64_RELOC_SUBTRACTOR
length: 3
pc-rel: false
extern: true
symbol: 2
- offset: 0x00000040
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: false
symbol: 2
- offset: 0x00000044
type: X86_64_RELOC_SUBTRACTOR
length: 2
pc-rel: false
extern: true
symbol: 2
- offset: 0x00000044
type: X86_64_RELOC_UNSIGNED
length: 2
pc-rel: false
extern: true
symbol: 0
- offset: 0x00000040
type: X86_64_RELOC_SUBTRACTOR
length: 2
pc-rel: false
extern: true
symbol: 2
- offset: 0x00000040
type: X86_64_RELOC_UNSIGNED
length: 2
pc-rel: false
extern: true
symbol: 0
- offset: 0x00000038
type: X86_64_RELOC_SUBTRACTOR
length: 3
@ -184,8 +222,8 @@ sections:
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: false
symbol: 2
extern: true
symbol: 0
- offset: 0x00000030
type: X86_64_RELOC_SUBTRACTOR
length: 3
@ -198,29 +236,29 @@ sections:
pc-rel: false
extern: true
symbol: 0
- offset: 0x00000028
type: X86_64_RELOC_SUBTRACTOR
length: 3
pc-rel: false
extern: true
symbol: 2
- offset: 0x00000028
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: true
symbol: 0
extern: false
symbol: 2
- offset: 0x00000020
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: false
symbol: 2
- offset: 0x00000018
type: X86_64_RELOC_SUBTRACTOR
length: 3
pc-rel: false
extern: true
symbol: 0
- offset: 0x00000018
type: X86_64_RELOC_UNSIGNED
length: 3
pc-rel: false
extern: false
extern: true
symbol: 2
- offset: 0x00000010
type: X86_64_RELOC_SUBTRACTOR
@ -268,10 +306,11 @@ page-size: 0x00000000
# CHECK: type: data
# CHECK: content: [ 00, 00, 00, 00, 00, 00, 00, 00, 04, 00, 00, 00,
# CHECK: 00, 00, 00, 00, F0, FF, FF, FF, FF, FF, FF, FF,
# CHECK: {{..}}, {{..}}, 00, 00, 00, 00, 00, 00, {{..}}, {{..}}, 00, 00,
# CHECK: 00, 00, 00, 00, D8, FF, FF, FF, FF, FF, FF, FF,
# CHECK: D4, FF, FF, FF, FF, FF, FF, FF, {{..}}, {{..}}, {{..}}, {{..}},
# CHECK: {{..}}, {{..}}, {{..}}, {{..}}, C0, FF, FF, FF, C0, FF, FF, FF,
# CHECK: 18, 00, 00, 00, 00, 00, 00, 00, {{..}}, {{..}}, 00, 00,
# CHECK: 00, 00, 00, 00, {{..}}, {{..}}, 00, 00, 00, 00, 00, 00,
# CHECK: D0, FF, FF, FF, FF, FF, FF, FF, CC, FF, FF, FF,
# CHECK: FF, FF, FF, FF, {{..}}, {{..}}, {{..}}, {{..}}, {{..}}, {{..}}, {{..}}, {{..}},
# CHECK: B8, FF, FF, FF, B4, FF, FF, FF, B4, FF, FF, FF,
# CHECK: {{..}}, {{..}}, {{..}}, {{..}} ]
# CHECK: dead-strip: never
# CHECK: references:
@ -285,32 +324,38 @@ page-size: 0x00000000
# CHECK: - kind: delta64
# CHECK: offset: 16
# CHECK: target: _foo
# CHECK: - kind: pointer64Anon
# CHECK: - kind: negDelta64
# CHECK: offset: 24
# CHECK: target: L003
# CHECK: target: _foo
# CHECK: - kind: pointer64Anon
# CHECK: offset: 32
# CHECK: target: L003
# CHECK: addend: 2
# CHECK: - kind: delta64
# CHECK: - kind: pointer64Anon
# CHECK: offset: 40
# CHECK: target: _foo
# CHECK: target: L003
# CHECK: addend: 2
# CHECK: - kind: delta64
# CHECK: offset: 48
# CHECK: target: _foo
# CHECK: - kind: delta64
# CHECK: offset: 56
# CHECK: target: _foo
# CHECK: addend: 4
# CHECK: - kind: delta64Anon
# CHECK: offset: 56
# CHECK: offset: 64
# CHECK: target: L003
# CHECK: - kind: delta32
# CHECK: offset: 64
# CHECK: offset: 72
# CHECK: target: _foo
# CHECK: - kind: negDelta32
# CHECK: offset: 76
# CHECK: target: _foo
# CHECK: - kind: delta32
# CHECK: offset: 68
# CHECK: offset: 80
# CHECK: target: _foo
# CHECK: addend: 4
# CHECK: - kind: delta32Anon
# CHECK: offset: 72
# CHECK: offset: 84
# CHECK: target: L003
# CHECK: - name: _foo
# CHECK: content: [ C3 ]