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smithp35smithp35
committedJul 20, 2016
Initial support for the local dynamic model ARM TLS relocations:
- R_ARM_TLS_LDM32 - R_ARM_TLS_LDO32 The local dynamic implementation and tests follows the same model as the other ARM TLS models. The R_ARM_TLS_LDO32 is implemented as R_ABS expr type as the getVA() for a TLS symbol will return the offset from the start of the TLS block. Differential Revision https://reviews.llvm.org/D22563 llvm-svn: 276123
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‎lld/ELF/Target.cpp

+11
Original file line numberDiff line numberDiff line change
@@ -178,6 +178,7 @@ class ARMTargetInfo final : public TargetInfo {
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RelExpr getRelExpr(uint32_t Type, const SymbolBody &S) const override;
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uint32_t getDynRel(uint32_t Type) const override;
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uint64_t getImplicitAddend(const uint8_t *Buf, uint32_t Type) const override;
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bool isTlsLocalDynamicRel(uint32_t Type) const override;
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bool isTlsGlobalDynamicRel(uint32_t Type) const override;
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bool isTlsInitialExecRel(uint32_t Type) const override;
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void writeGotPlt(uint8_t *Buf, const SymbolBody &S) const override;
@@ -1523,6 +1524,8 @@ RelExpr ARMTargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
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return R_GOT_PC;
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case R_ARM_TLS_GD32:
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return R_TLSGD_PC;
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case R_ARM_TLS_LDM32:
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return R_TLSLD_PC;
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case R_ARM_BASE_PREL:
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// B(S) + A - P
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// FIXME: currently B(S) assumed to be .got, this may not hold for all
@@ -1624,6 +1627,8 @@ void ARMTargetInfo::relocateOne(uint8_t *Loc, uint32_t Type,
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case R_ARM_REL32:
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case R_ARM_TLS_GD32:
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case R_ARM_TLS_IE32:
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case R_ARM_TLS_LDM32:
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case R_ARM_TLS_LDO32:
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case R_ARM_TLS_LE32:
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write32le(Loc, Val);
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break;
@@ -1749,6 +1754,8 @@ uint64_t ARMTargetInfo::getImplicitAddend(const uint8_t *Buf,
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case R_ARM_GOT_PREL:
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case R_ARM_REL32:
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case R_ARM_TLS_GD32:
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case R_ARM_TLS_LDM32:
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case R_ARM_TLS_LDO32:
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case R_ARM_TLS_IE32:
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case R_ARM_TLS_LE32:
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return SignExtend64<32>(read32le(Buf));
@@ -1808,6 +1815,10 @@ uint64_t ARMTargetInfo::getImplicitAddend(const uint8_t *Buf,
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}
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}
18101817

1818+
bool ARMTargetInfo::isTlsLocalDynamicRel(uint32_t Type) const {
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return Type == R_ARM_TLS_LDO32 || Type == R_ARM_TLS_LDM32;
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}
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bool ARMTargetInfo::isTlsGlobalDynamicRel(uint32_t Type) const {
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return Type == R_ARM_TLS_GD32;
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}

‎lld/test/ELF/arm-tls-ldm32.s

+73
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,73 @@
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// RUN: llvm-mc %s -o %t.o -filetype=obj -triple=armv7a-linux-gnueabi
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// RUN: ld.lld %t.o -o %t.so -shared
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// RUN: llvm-readobj -s -dyn-relocations %t.so | FileCheck --check-prefix=SEC %s
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// RUN: llvm-objdump -d -triple=armv7a-linux-gnueabi %t.so | FileCheck %s
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// REQUIRES: arm
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// Test the handling of the local-dynamic TLS model. Dynamic loader finds
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// module index R_ARM_TLS_DTPMOD32. The offset in the next GOT slot is 0
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// The R_ARM_TLS_LDO is the offset of the variable within the TLS block.
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.global __tls_get_addr
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.text
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.p2align 2
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.global _start
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.syntax unified
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.arm
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.type _start, %function
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_start:
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.L0:
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nop
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.word x(tlsldm) + (. - .L0 - 8)
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.word x(tlsldo)
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.word y(tlsldo)
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.section .tbss,"awT",%nobits
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.p2align 2
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.type y, %object
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y:
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.space 4
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.section .tdata,"awT",%progbits
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.p2align 2
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.type x, %object
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x:
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.word 10
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// SEC: Name: .tdata
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// SEC-NEXT: Type: SHT_PROGBITS
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// SEC-NEXT: Flags [
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// SEC-NEXT: SHF_ALLOC
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// SEC-NEXT: SHF_TLS
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// SEC-NEXT: SHF_WRITE
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// SEC-NEXT: ]
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// SEC-NEXT: Address: 0x2000
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// SEC: Size: 4
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// SEC: Name: .tbss
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// SEC-NEXT: Type: SHT_NOBITS (0x8)
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// SEC-NEXT: Flags [
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// SEC-NEXT: SHF_ALLOC
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// SEC-NEXT: SHF_TLS
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// SEC-NEXT: SHF_WRITE
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// SEC-NEXT: ]
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// SEC-NEXT: Address: 0x2004
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// SEC: Size: 4
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55+
// SEC: Dynamic Relocations {
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// SEC-NEXT: 0x204C R_ARM_TLS_DTPMOD32 - 0x0
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58+
// CHECK: Disassembly of section .text:
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// CHECK-NEXT: _start:
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// CHECK-NEXT: 1000: 00 f0 20 e3 nop
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// (0x204c - 0x1004) + (0x1004 - 0x1000 - 8) = 0x1044
63+
// CHECK: 1004: 44 10 00 00
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// CHECK-NEXT: 1008: 00 00 00 00
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// CHECK-NEXT: 100c: 04 00 00 00
66+
67+
// CHECK-EXE: Disassembly of section .text:
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// CHECK-NEXT-EXE: _start:
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// CHECK-NEXT-EXE: 11000: 00 f0 20 e3 nop
70+
71+
// CHECK-EXE: 11004: fc 0f 00 00
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// CHECK-EXE: 11008: 00 00 00 00
73+
// CHECK-EXE: 1100c: 04 00 00 00

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