Index: ELF/Config.h
===================================================================
--- ELF/Config.h
+++ ELF/Config.h
@@ -64,6 +64,7 @@
bool ZNodelete = false;
bool ZNow = false;
bool ZOrigin = false;
+ bool ZRelro = false;
ELFKind EKind = ELFNoneKind;
uint16_t EMachine = llvm::ELF::EM_NONE;
uint64_t EntryAddr = -1;
Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -186,6 +186,10 @@
Config->ZNow = true;
else if (S == "origin")
Config->ZOrigin = true;
+ else if (S == "relro")
+ Config->ZRelro = true;
+ else if (S == "norelro")
+ Config->ZRelro = false;
}
for (auto *Arg : Args) {
Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -45,6 +45,8 @@
void scanRelocs(const InputSection<ELFT> &C,
iterator_range<const Elf_Rel_Impl<ELFT, isRela> *> Rels);
void scanRelocs(const InputSection<ELFT> &C);
+ void updateRelRo(Elf_Phdr *Cur, Elf_Phdr *GnuRelroPhdr,
+ OutputSectionBase<ELFT> *Sec, uintX_t VA);
void assignAddresses();
void openFile(StringRef OutputPath);
void writeHeader();
@@ -319,6 +321,12 @@
.Default(1);
}
+template <class ELFT> static bool isRelroSection(OutputSectionBase<ELFT> *Sec) {
+ if (Sec == Out<ELFT>::GotPlt)
+ return Config->ZNow;
+ return (Sec->getName() != ".data" && Sec->getType() != SHT_NOBITS);
+}
+
// Output section ordering is determined by this function.
template <class ELFT>
static bool compareOutputSections(OutputSectionBase<ELFT> *A,
@@ -375,6 +383,11 @@
if (AIsNoBits != BIsNoBits)
return BIsNoBits;
+ bool AIsRelRo = isRelroSection(A);
+ bool BIsRelRo = isRelroSection(B);
+ if (AIsRelRo != BIsRelRo)
+ return AIsRelRo;
+
// Some architectures have additional ordering restrictions for sections
// within the same PT_LOAD.
if (Config->EMachine == EM_PPC64)
@@ -673,6 +686,23 @@
return Ret;
}
+template <class ELFT>
+void Writer<ELFT>::updateRelRo(Elf_Phdr *Cur, Elf_Phdr *GnuRelroPhdr,
+ OutputSectionBase<ELFT> *Sec, uintX_t VA) {
+
+ if (!Config->ZRelro || !(Cur->p_flags & PF_W))
+ return;
+
+ if (isRelroSection(Sec)) {
+ if (!GnuRelroPhdr->p_type)
+ setPhdr(GnuRelroPhdr, PT_GNU_RELRO, PF_R, Cur->p_offset, Cur->p_vaddr,
+ VA - Cur->p_vaddr, 1 /*p_align*/);
+
+ GnuRelroPhdr->p_filesz = VA - Cur->p_vaddr;
+ GnuRelroPhdr->p_memsz = VA - Cur->p_vaddr;
+ }
+}
+
// Visits all sections to create PHDRs and to assign incremental,
// non-overlapping addresses to output sections.
template <class ELFT> void Writer<ELFT>::assignAddresses() {
@@ -699,6 +729,7 @@
setPhdr(&Phdrs[++PhdrIdx], PT_LOAD, PF_R, 0, Target->getVAStart(), FileOff,
Target->getPageSize());
+ Elf_Phdr GnuRelroPhdr = {};
Elf_Phdr TlsPhdr{};
uintX_t ThreadBSSOffset = 0;
// Create phdrs as we assign VAs and file offsets to all output sections.
@@ -732,6 +763,8 @@
VA = RoundUpToAlignment(VA, Sec->getAlign());
Sec->setVA(VA);
VA += Sec->getSize();
+
+ updateRelRo(&Phdrs[PhdrIdx], &GnuRelroPhdr, Sec, VA);
}
}
@@ -767,6 +800,11 @@
copyPhdr(Interp, Out<ELFT>::Interp);
}
+ if (GnuRelroPhdr.p_filesz) {
+ Elf_Phdr *PH = &Phdrs[++PhdrIdx];
+ *PH = GnuRelroPhdr;
+ }
+
// Add space for section headers.
SectionHeaderOff = RoundUpToAlignment(FileOff, ELFT::Is64Bits ? 8 : 4);
FileSize = SectionHeaderOff + getNumSections() * sizeof(Elf_Shdr);
@@ -798,6 +836,8 @@
}
if (Tls)
++I;
+ if (Config->ZRelro)
+ ++I;
return I;
}
Index: test/elf2/mips-got-relocs.s
===================================================================
--- test/elf2/mips-got-relocs.s
+++ test/elf2/mips-got-relocs.s
@@ -45,21 +45,21 @@
.word 0
# EXE_SYM: Sections:
-# EXE_SYM: .got 0000000c 0000000000030004 DATA
+# EXE_SYM: .got 0000000c 0000000000030000 DATA
# EXE_SYM: SYMBOL TABLE:
-# EXE_SYM: 00037ff4 *ABS* 00000000 _gp
+# EXE_SYM: 00037ff0 *ABS* 00000000 _gp
# ^-- .got + GP offset (0x7ff0)
-# EXE_SYM: 00030000 g .data 00000004 v1
+# EXE_SYM: 00030010 g .data 00000004 v1
# EXE_GOT_BE: Contents of section .got:
-# EXE_GOT_BE: 30004 00000000 80000000 00030000
-# ^ ^ ^-- v1 (0x30000)
+# EXE_GOT_BE: 30000 00000000 80000000 00030010
+# ^ ^ ^-- v1 (0x30010)
# | +-- Module pointer (0x80000000)
# +-- Lazy resolver (0x0)
# EXE_GOT_EL: Contents of section .got:
-# EXE_GOT_EL: 30004 00000000 00000080 00000300
-# ^ ^ ^-- v1 (0x30000)
+# EXE_GOT_EL: 30000 00000000 00000080 10000300
+# ^ ^ ^-- v1 (0x30010)
# | +-- Module pointer (0x80000000)
# +-- Lazy resolver (0x0)
@@ -68,21 +68,21 @@
# EXE_DIS_EL: 20000: 18 80 02 3c lui $2, 32792
# DSO_SYM: Sections:
-# DSO_SYM: .got 0000000c 0000000000020034 DATA
+# DSO_SYM: .got 0000000c 0000000000020030 DATA
# DSO_SYM: SYMBOL TABLE:
-# DSO_SYM: 00028024 *ABS* 00000000 _gp
+# DSO_SYM: 00028020 *ABS* 00000000 _gp
# ^-- .got + GP offset (0x7ff0)
-# DSO_SYM: 00020000 g .data 00000004 v1
+# DSO_SYM: 00020040 g .data 00000004 v1
# DSO_GOT_BE: Contents of section .got:
-# DSO_GOT_BE: 20034 00000000 80000000 00020000
-# ^ ^ ^-- v1 (0x20000)
+# DSO_GOT_BE: 20030 00000000 80000000 00020040
+# ^ ^ ^-- v1 (0x20040)
# | +-- Module pointer (0x80000000)
# +-- Lazy resolver (0x0)
# DSO_GOT_EL: Contents of section .got:
-# DSO_GOT_EL: 20034 00000000 00000080 00000200
-# ^ ^ ^-- v1 (0x20000)
+# DSO_GOT_EL: 20030 00000000 00000080 40000200
+# ^ ^ ^-- v1 (0x20040)
# | +-- Module pointer (0x80000000)
# +-- Lazy resolver (0x0)
Index: test/elf2/relro.s
===================================================================
--- test/elf2/relro.s
+++ test/elf2/relro.s
@@ -0,0 +1,224 @@
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/shared.s -o %t2.o
+// RUN: ld.lld2 -shared %t2.o -o %t2.so
+// RUN: ld.lld2 %t.o %t2.so -z now -z relro -o %t
+// RUN: llvm-readobj --program-headers --dynamic-table -t -s -dyn-symbols -section-data %t | FileCheck --check-prefix=FULLRELRO %s
+// RUN: ld.lld2 %t.o %t2.so -z relro -o %t
+// RUN: llvm-readobj --program-headers --dynamic-table -t -s -dyn-symbols -section-data %t | FileCheck --check-prefix=PARTRELRO %s
+// RUN: ld.lld2 %t.o %t2.so -z norelro -o %t
+// RUN: llvm-readobj --program-headers --dynamic-table -t -s -dyn-symbols -section-data %t | FileCheck --check-prefix=NORELRO %s
+// RUN: ld.lld2 %t.o %t2.so -o %t
+// RUN: llvm-readobj --program-headers --dynamic-table -t -s -dyn-symbols -section-data %t | FileCheck --check-prefix=NORELRO %s
+// REQUIRES: x86
+
+// FULLRELRO: Section {
+// FULLRELRO: Index: 9
+// FULLRELRO-NEXT: Name: .got
+// FULLRELRO-NEXT: Type: SHT_PROGBITS
+// FULLRELRO-NEXT: Flags [
+// FULLRELRO-NEXT: SHF_ALLOC
+// FULLRELRO-NEXT: SHF_WRITE
+// FULLRELRO-NEXT: ]
+// FULLRELRO-NEXT: Address: 0x12100
+// FULLRELRO-NEXT: Offset: 0x2100
+// FULLRELRO-NEXT: Size: 8
+// FULLRELRO-NEXT: Link: 0
+// FULLRELRO-NEXT: Info: 0
+// FULLRELRO-NEXT: AddressAlignment: 8
+// FULLRELRO-NEXT: EntrySize: 0
+// FULLRELRO-NEXT: SectionData (
+// FULLRELRO-NEXT: 0000: 00000000 00000000
+// FULLRELRO-NEXT: )
+// FULLRELRO-NEXT: }
+// FULLRELRO-NEXT: Section {
+// FULLRELRO-NEXT: Index: 10
+// FULLRELRO-NEXT: Name: .got.plt
+// FULLRELRO-NEXT: Type: SHT_PROGBITS
+// FULLRELRO-NEXT: Flags [
+// FULLRELRO-NEXT: SHF_ALLOC
+// FULLRELRO-NEXT: SHF_WRITE
+// FULLRELRO-NEXT: ]
+// FULLRELRO-NEXT: Address: 0x12108
+// FULLRELRO-NEXT: Offset: 0x2108
+// FULLRELRO-NEXT: Size: 32
+// FULLRELRO-NEXT: Link: 0
+// FULLRELRO-NEXT: Info: 0
+// FULLRELRO-NEXT: AddressAlignment: 8
+// FULLRELRO-NEXT: EntrySize: 0
+// FULLRELRO-NEXT: SectionData (
+// FULLRELRO-NEXT: 0000:
+// FULLRELRO-NEXT: 0010:
+// FULLRELRO-NEXT: )
+// FULLRELRO-NEXT: }
+// FULLRELRO-NEXT: Section {
+// FULLRELRO-NEXT: Index: 11
+// FULLRELRO-NEXT: Name: .data
+// FULLRELRO-NEXT: Type: SHT_PROGBITS
+// FULLRELRO-NEXT: Flags [
+// FULLRELRO-NEXT: SHF_ALLOC
+// FULLRELRO-NEXT: SHF_WRITE
+// FULLRELRO-NEXT: ]
+// FULLRELRO-NEXT: Address: 0x12128
+// FULLRELRO-NEXT: Offset: 0x2128
+// FULLRELRO-NEXT: Size: 12
+// FULLRELRO-NEXT: Link: 0
+// FULLRELRO-NEXT: Info: 0
+// FULLRELRO-NEXT: AddressAlignment:
+// FULLRELRO-NEXT: EntrySize: 0
+// FULLRELRO-NEXT: SectionData (
+// FULLRELRO-NEXT: 0000:
+// FULLRELRO-NEXT: )
+// FULLRELRO-NEXT: }
+// FULLRELRO-NEXT: Section {
+// FULLRELRO-NEXT: Index: 12
+// FULLRELRO-NEXT: Name: .bss
+// FULLRELRO-NEXT: Type: SHT_NOBITS
+// FULLRELRO-NEXT: Flags [
+// FULLRELRO-NEXT: SHF_ALLOC
+// FULLRELRO-NEXT: SHF_WRITE
+// FULLRELRO-NEXT: ]
+// FULLRELRO-NEXT: Address: 0x12134
+// FULLRELRO-NEXT: Offset: 0x2134
+// FULLRELRO-NEXT: Size: 0
+// FULLRELRO-NEXT: Link: 0
+// FULLRELRO-NEXT: Info: 0
+// FULLRELRO-NEXT: AddressAlignment:
+// FULLRELRO-NEXT: EntrySize: 0
+// FULLRELRO-NEXT: }
+// 308 - sizeof(.data)(12) = 296
+// FULLRELRO: ProgramHeaders [
+// FULLRELRO: Type: PT_LOAD
+// FULLRELRO: Offset: 0x2000
+// FULLRELRO-NEXT: VirtualAddress: [[RWADDR:.*]]
+// FULLRELRO-NEXT: PhysicalAddress:
+// FULLRELRO-NEXT: FileSize: 308
+// FULLRELRO-NEXT: MemSize: 308
+// FULLRELRO-NEXT: Flags [
+// FULLRELRO-NEXT: PF_R
+// FULLRELRO-NEXT: PF_W
+// FULLRELRO-NEXT: ]
+// FULLRELRO-NEXT: Alignment: 4096
+// FULLRELRO-NEXT:}
+// FULLRELRO: Type: PT_GNU_RELRO
+// FULLRELRO-NEXT: Offset: 0x
+// FULLRELRO-NEXT: VirtualAddress: [[RWADDR]]
+// FULLRELRO-NEXT: PhysicalAddress:
+// FULLRELRO-NEXT: FileSize: 296
+// FULLRELRO-NEXT: MemSize: 296
+// FULLRELRO-NEXT: Flags [
+// FULLRELRO-NEXT: PF_R
+// FULLRELRO-NEXT: ]
+// FULLRELRO-NEXT: Alignment: 1
+// FULLRELRO-NEXT:}
+
+// PARTRELRO: Section {
+// PARTRELRO: Index: 9
+// PARTRELRO-NEXT: Name: .got
+// PARTRELRO-NEXT: Type: SHT_PROGBITS
+// PARTRELRO-NEXT: Flags [
+// PARTRELRO-NEXT: SHF_ALLOC
+// PARTRELRO-NEXT: SHF_WRITE
+// PARTRELRO-NEXT: ]
+// PARTRELRO-NEXT: Address: 0x120E0
+// PARTRELRO-NEXT: Offset: 0x20E0
+// PARTRELRO-NEXT: Size: 8
+// PARTRELRO-NEXT: Link: 0
+// PARTRELRO-NEXT: Info: 0
+// PARTRELRO-NEXT: AddressAlignment: 8
+// PARTRELRO-NEXT: EntrySize: 0
+// PARTRELRO-NEXT: SectionData (
+// PARTRELRO-NEXT: 0000:
+// PARTRELRO-NEXT: )
+// PARTRELRO-NEXT: }
+// PARTRELRO-NEXT: Section {
+// PARTRELRO-NEXT: Index: 10
+// PARTRELRO-NEXT: Name: .data
+// PARTRELRO-NEXT: Type: SHT_PROGBITS
+// PARTRELRO-NEXT: Flags [
+// PARTRELRO-NEXT: SHF_ALLOC
+// PARTRELRO-NEXT: SHF_WRITE
+// PARTRELRO-NEXT: ]
+// PARTRELRO-NEXT: Address: 0x120E8
+// PARTRELRO-NEXT: Offset: 0x20E8
+// PARTRELRO-NEXT: Size: 12
+// PARTRELRO-NEXT: Link: 0
+// PARTRELRO-NEXT: Info: 0
+// PARTRELRO-NEXT: AddressAlignment: 1
+// PARTRELRO-NEXT: EntrySize: 0
+// PARTRELRO-NEXT: SectionData (
+// PARTRELRO-NEXT: 0000:
+// PARTRELRO-NEXT: )
+// PARTRELRO-NEXT: }
+// PARTRELRO-NEXT: Section {
+// PARTRELRO-NEXT: Index: 11
+// PARTRELRO-NEXT: Name: .got.plt
+// PARTRELRO-NEXT: Type: SHT_PROGBITS
+// PARTRELRO-NEXT: Flags [
+// PARTRELRO-NEXT: SHF_ALLOC
+// PARTRELRO-NEXT: SHF_WRITE
+// PARTRELRO-NEXT: ]
+// PARTRELRO-NEXT: Address: 0x120F8
+// PARTRELRO-NEXT: Offset: 0x20F8
+// PARTRELRO-NEXT: Size: 32
+// PARTRELRO-NEXT: Link: 0
+// PARTRELRO-NEXT: Info: 0
+// PARTRELRO-NEXT: AddressAlignment: 8
+// PARTRELRO-NEXT: EntrySize: 0
+// PARTRELRO-NEXT: SectionData (
+// PARTRELRO-NEXT: 0000:
+// PARTRELRO-NEXT: 0010:
+// PARTRELRO-NEXT: )
+// PARTRELRO-NEXT: }
+// PARTRELRO-NEXT: Section {
+// PARTRELRO-NEXT: Index: 12
+// PARTRELRO-NEXT: Name: .bss
+// PARTRELRO-NEXT: Type: SHT_NOBITS
+// PARTRELRO-NEXT: Flags [
+// PARTRELRO-NEXT: SHF_ALLOC
+// PARTRELRO-NEXT: SHF_WRITE
+// PARTRELRO-NEXT: ]
+// PARTRELRO-NEXT: Address: 0x12118
+// PARTRELRO-NEXT: Offset: 0x2118
+// PARTRELRO-NEXT: Size: 0
+// PARTRELRO-NEXT: Link: 0
+// PARTRELRO-NEXT: Info: 0
+// PARTRELRO-NEXT: AddressAlignment: 1
+// PARTRELRO-NEXT: EntrySize: 0
+// PARTRELRO-NEXT: }
+// 232 + sizeof(.data)(12) + align(4) + sizeof(.got.plt)(32) = 280
+// PARTRELRO: ProgramHeader {
+// PARTRELRO: Type: PT_LOAD
+// PARTRELRO: Offset: 0x2000
+// PARTRELRO-NEXT: VirtualAddress: [[RWADDR:.*]]
+// PARTRELRO-NEXT: PhysicalAddress:
+// PARTRELRO-NEXT: FileSize: 280
+// PARTRELRO-NEXT: MemSize: 280
+// PARTRELRO-NEXT: Flags [
+// PARTRELRO-NEXT: PF_R (0x4)
+// PARTRELRO-NEXT: PF_W (0x2)
+// PARTRELRO-NEXT: ]
+// PARTRELRO-NEXT: Alignment: 4096
+// PARTRELRO: Type: PT_GNU_RELRO
+// PARTRELRO-NEXT: Offset: 0x2000
+// PARTRELRO-NEXT: VirtualAddress: [[RWADDR]]
+// PARTRELRO-NEXT: PhysicalAddress:
+// PARTRELRO-NEXT: FileSize: 232
+// PARTRELRO-NEXT: MemSize: 232
+// PARTRELRO-NEXT: Flags [
+// PARTRELRO-NEXT: PF_R
+// PARTRELRO-NEXT: ]
+// PARTRELRO-NEXT: Alignment: 1
+
+// NORELRO: ProgramHeaders [
+// NORELRO-NOT: PT_GNU_RELRO
+
+.global _start
+_start:
+ .long bar
+ jmp *bar@GOTPCREL(%rip)
+
+.section .data,"aw"
+.quad 0
+
+.zero 4
+.bss
Index: test/elf2/section-name.s
===================================================================
--- test/elf2/section-name.s
+++ test/elf2/section-name.s
@@ -22,9 +22,9 @@
// CHECK: Name: .rodata
// CHECK-NOT: Name: .text.a
// CHECK: Name: .text
-// CHECK-NOT: Name: .data.a
-// CHECK: Name: .data
// CHECK: Name: .foo.a
// CHECK: Name: .foo
+// CHECK-NOT: Name: .data.a
+// CHECK: Name: .data
// CHECK-NOT: Name: .bss.a
// CHECK: Name: .bss