[lld] r233532 - [Mips] Fix writing R_MIPS_REL32 relocation addendum
Simon Atanasyan
simon at atanasyan.com
Mon Mar 30 04:39:02 PDT 2015
Author: atanasyan
Date: Mon Mar 30 06:39:02 2015
New Revision: 233532
URL: http://llvm.org/viewvc/llvm-project?rev=233532&view=rev
Log:
[Mips] Fix writing R_MIPS_REL32 relocation addendum
If input relocation records have RELA format while output dynamic
relocations have REL format the only way to transfer a dynamic
relocation addendum is to save it into the location modified by
the dynamic relocation.
Added:
lld/trunk/test/elf/Mips/rel-dynamic-13.test
lld/trunk/test/elf/Mips/rel-dynamic-14.test
Modified:
lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp
lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.h
lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationHandler.cpp
Modified: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp?rev=233532&r1=233531&r2=233532&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp (original)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.cpp Mon Mar 30 06:39:02 2015
@@ -113,3 +113,17 @@ bool MipsLinkingContext::isPLTRelocation
return false;
}
}
+
+bool MipsLinkingContext::isRelativeReloc(const Reference &r) const {
+ if (r.kindNamespace() != Reference::KindNamespace::ELF)
+ return false;
+ assert(r.kindArch() == Reference::KindArch::Mips);
+ switch (r.kindValue()) {
+ case llvm::ELF::R_MIPS_REL32:
+ case llvm::ELF::R_MIPS_GPREL16:
+ case llvm::ELF::R_MIPS_GPREL32:
+ return true;
+ default:
+ return false;
+ }
+}
Modified: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.h?rev=233532&r1=233531&r2=233532&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.h (original)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsLinkingContext.h Mon Mar 30 06:39:02 2015
@@ -57,6 +57,7 @@ public:
bool isDynamicRelocation(const Reference &r) const override;
bool isCopyRelocation(const Reference &r) const override;
bool isPLTRelocation(const Reference &r) const override;
+ bool isRelativeReloc(const Reference &r) const override;
private:
MipsELFFlagsMerger _flagsMerger;
Modified: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationHandler.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationHandler.cpp?rev=233532&r1=233531&r2=233532&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationHandler.cpp (original)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationHandler.cpp Mon Mar 30 06:39:02 2015
@@ -124,6 +124,7 @@ static MipsRelocationParams getRelocatio
case R_MICROMIPS_JALR:
return {4, 0x0, 0, true};
case R_MIPS_REL32:
+ return {4, 0xffffffff, 0, false};
case R_MIPS_JUMP_SLOT:
case R_MIPS_COPY:
case R_MIPS_TLS_DTPMOD32:
@@ -554,6 +555,13 @@ std::error_code RelocationHandler<ELFT>:
if (auto ec = res.getError())
return ec;
+ // If output relocation format is REL and the input one is RELA, the only
+ // method to transfer the relocation addend from the input relocation
+ // to the output dynamic relocation is to save this addend to the location
+ // modified by R_MIPS_REL32.
+ if (ref.kindValue() == R_MIPS_REL32 && !_ctx.isRelaOutputFormat())
+ res = ref.addend();
+
Reference::KindValue op = ref.kindValue();
// FIXME (simon): Handle r_ssym value.
Added: lld/trunk/test/elf/Mips/rel-dynamic-13.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/Mips/rel-dynamic-13.test?rev=233532&view=auto
==============================================================================
--- lld/trunk/test/elf/Mips/rel-dynamic-13.test (added)
+++ lld/trunk/test/elf/Mips/rel-dynamic-13.test Mon Mar 30 06:39:02 2015
@@ -0,0 +1,94 @@
+# Conditions:
+# a) Linking a non-shared 32-bit executable file.
+# b) Relocations' targets are symbols defined in the shared object.
+# Check:
+# a) Emitting R_MIPS_REL32 relocation.
+# b) Applying addendum from the original relocation.
+#
+# RUN: yaml2obj -format=elf -docnum 1 %s > %t-so.o
+# RUN: lld -flavor gnu -target mipsel -shared -o %t.so %t-so.o
+# RUN: yaml2obj -format=elf -docnum 2 %s > %t-o.o
+# RUN: lld -flavor gnu -target mipsel -e T0 -o %t.exe %t-o.o %t.so
+# RUN: llvm-objdump -s %t.exe | FileCheck -check-prefix=RAW %s
+# RUN: llvm-readobj -r %t.exe | FileCheck -check-prefix=REL %s
+
+# RAW: Contents of section .data:
+# RAW-NEXT: 402000 01000000
+
+# REL: Relocations [
+# REL-NEXT: Section (5) .rel.dyn {
+# REL-NEXT: 0x402000 R_MIPS_REL32 T1 0x0
+# REL-NEXT: }
+# REL-NEXT: ]
+
+# so.o
+---
+FileHeader:
+ Class: ELFCLASS32
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [EF_MIPS_PIC, EF_MIPS_CPIC, EF_MIPS_ABI_O32, EF_MIPS_ARCH_32]
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Size: 4
+ AddressAlign: 16
+ Flags: [SHF_EXECINSTR, SHF_ALLOC]
+
+Symbols:
+ Global:
+ - Name: T1
+ Section: .text
+ Type: STT_FUNC
+ Value: 0
+ Size: 4
+
+# o.o
+---
+FileHeader:
+ Class: ELFCLASS32
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [EF_MIPS_CPIC, EF_MIPS_ABI_O32, EF_MIPS_ARCH_32]
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Size: 4
+ AddressAlign: 16
+ Flags: [SHF_EXECINSTR, SHF_ALLOC]
+
+- Name: .data
+ Type: SHT_PROGBITS
+ Size: 4
+ AddressAlign: 16
+ Flags: [SHF_WRITE, SHF_ALLOC]
+
+- Name: .rel.data
+ Type: SHT_RELA
+ Info: .data
+ AddressAlign: 4
+ Relocations:
+ - Offset: 0
+ Symbol: T1
+ Type: R_MIPS_32
+ Addend: 1
+
+Symbols:
+ Global:
+ - Name: T0
+ Section: .text
+ Type: STT_FUNC
+ Value: 0
+ Size: 4
+ - Name: T1
+ Type: STT_FUNC
+ - Name: D0
+ Section: .data
+ Type: STT_OBJECT
+ Value: 0
+ Size: 4
+...
Added: lld/trunk/test/elf/Mips/rel-dynamic-14.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/Mips/rel-dynamic-14.test?rev=233532&view=auto
==============================================================================
--- lld/trunk/test/elf/Mips/rel-dynamic-14.test (added)
+++ lld/trunk/test/elf/Mips/rel-dynamic-14.test Mon Mar 30 06:39:02 2015
@@ -0,0 +1,94 @@
+# Conditions:
+# a) Linking a non-shared 64-bit executable file.
+# b) Relocations' targets are symbols defined in the shared object.
+# Check:
+# a) Emitting R_MIPS_REL32/R_MIPS_64 relocation.
+# b) Applying addendum from the original relocation.
+#
+# RUN: yaml2obj -format=elf -docnum 1 %s > %t-so.o
+# RUN: lld -flavor gnu -target mips64el -shared -o %t.so %t-so.o
+# RUN: yaml2obj -format=elf -docnum 2 %s > %t-o.o
+# RUN: lld -flavor gnu -target mips64el -e T0 -o %t.exe %t-o.o %t.so
+# RUN: llvm-objdump -s %t.exe | FileCheck -check-prefix=RAW %s
+# RUN: llvm-readobj -r %t.exe | FileCheck -check-prefix=REL %s
+
+# RAW: Contents of section .data:
+# RAW-NEXT: 120002000 04000000 00000000
+
+# REL: Relocations [
+# REL-NEXT: Section (5) .rel.dyn {
+# REL-NEXT: 0x120002000 R_MIPS_REL32/R_MIPS_64/R_MIPS_NONE T1 0x0
+# REL-NEXT: }
+# REL-NEXT: ]
+
+# so.o
+---
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [EF_MIPS_PIC, EF_MIPS_CPIC, EF_MIPS_ARCH_64]
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Size: 4
+ AddressAlign: 16
+ Flags: [SHF_EXECINSTR, SHF_ALLOC]
+
+Symbols:
+ Global:
+ - Name: T1
+ Section: .text
+ Type: STT_FUNC
+ Value: 0
+ Size: 4
+
+# o.o
+---
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [EF_MIPS_PIC, EF_MIPS_CPIC, EF_MIPS_ARCH_64]
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Size: 4
+ AddressAlign: 16
+ Flags: [SHF_EXECINSTR, SHF_ALLOC]
+
+- Name: .data
+ Type: SHT_PROGBITS
+ Size: 8
+ AddressAlign: 16
+ Flags: [SHF_WRITE, SHF_ALLOC]
+
+- Name: .rel.data
+ Type: SHT_RELA
+ Info: .data
+ AddressAlign: 4
+ Relocations:
+ - Offset: 0
+ Symbol: T1
+ Type: R_MIPS_64
+ Addend: 4
+
+Symbols:
+ Global:
+ - Name: T0
+ Section: .text
+ Type: STT_FUNC
+ Value: 0
+ Size: 4
+ - Name: T1
+ Type: STT_FUNC
+ - Name: D0
+ Section: .data
+ Type: STT_OBJECT
+ Value: 0
+ Size: 4
+...
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