diff options
| -rw-r--r-- | lld/ELF/Writer.cpp | 18 | ||||
| -rw-r--r-- | lld/test/ELF/relro-non-contiguous-zerosize.s | 62 |
2 files changed, 79 insertions, 1 deletions
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp index d2499fb54c5..ab1c5fe3ac9 100644 --- a/lld/ELF/Writer.cpp +++ b/lld/ELF/Writer.cpp @@ -1452,6 +1452,22 @@ static uint64_t computeFlags(uint64_t Flags) { return Flags; } +// Prior to finalizeContents() an OutputSection containing SyntheticSections +// may have 0 Size, but contain SyntheticSections that haven't had their size +// calculated yet. We must use SyntheticSection->empty() for these sections. +static bool isOutputSectionZeroSize(const OutputSection* Sec) { + if (Sec->Size > 0) + return false; + for (BaseCommand *BC : Sec->SectionCommands) { + if (auto *ISD = dyn_cast<InputSectionDescription>(BC)) + for (InputSection *IS : ISD->Sections) + if (SyntheticSection *SS = dyn_cast<SyntheticSection>(IS)) + if (!SS->empty()) + return false; + } + return true; +} + // Decide which program headers to create and which sections to include in each // one. template <class ELFT> std::vector<PhdrEntry *> Writer<ELFT>::createPhdrs() { @@ -1517,7 +1533,7 @@ template <class ELFT> std::vector<PhdrEntry *> Writer<ELFT>::createPhdrs() { bool InRelroPhdr = false; bool IsRelroFinished = false; for (OutputSection *Sec : OutputSections) { - if (!needsPtLoad(Sec)) + if (!needsPtLoad(Sec) || isOutputSectionZeroSize(Sec)) continue; if (isRelroSection(Sec)) { InRelroPhdr = true; diff --git a/lld/test/ELF/relro-non-contiguous-zerosize.s b/lld/test/ELF/relro-non-contiguous-zerosize.s new file mode 100644 index 00000000000..27ba770f2b2 --- /dev/null +++ b/lld/test/ELF/relro-non-contiguous-zerosize.s @@ -0,0 +1,62 @@ +// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/shared.s -o %t.o +// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/copy-in-shared.s -o %t2.o +// RUN: ld.lld -shared %t.o %t2.o -o %t.so + +// Check that we ignore zero sized non-relro sections that are covered by the +// range of addresses covered by the PT_GNU_RELRO header. +// Check that we ignore zero sized relro sections that are disjoint from the +// range of addresses covered by the PT_GNU_RELRO header. +// REQUIRES: x86 + +// RUN: echo "SECTIONS { \ +// RUN: .ctors : { *(.ctors) } \ +// RUN: .large1 : { *(.large1) } \ +// RUN: .dynamic : { *(.dynamic) } \ +// RUN: .zero_size : { *(.zero_size) } \ +// RUN: .jcr : { *(.jcr) } \ +// RUN: .got.plt : { *(.got.plt) } \ +// RUN: .large2 : { *(.large2) } \ +// RUN: .data.rel.ro : { *(.data.rel.ro.*) } \ +// RUN: } " > %t.script +// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t3.o +// RUN: ld.lld %t3.o %t.so -o %t --script=%t.script +// RUN: llvm-readobj -program-headers %t | FileCheck %s + +// CHECK: Type: PT_GNU_RELRO +// CHECK-NEXT: Offset: +// CHECK-NEXT: VirtualAddress: +// CHECK-NEXT: PhysicalAddress: +// CHECK-NEXT: FileSize: +// CHECK-NEXT: MemSize: 4096 + + .section .text, "ax", @progbits + .global _start + .global bar + .global foo +_start: + callq bar + + // page size non-relro sections that would alter PT_GNU_RELRO header + // MemSize if counted as part of relro. + .section .large1, "aw", @progbits + .space 4 * 1024 + + .section .large2, "aw", @progbits + .space 4 * 1024 + + // empty relro section + .section .ctors, "aw", @progbits + + // non-empty relro section + .section .jcr, "aw", @progbits + .quad 0 + + // empty non-relro section + .section .zero_size, "aw", @progbits + .global sym +sym: + + // empty relro section + .section .data.rel.ro, "aw", @progbits + .global sym2 +sym2: |
