[LLD] Support compressed input sections on big-endian targets

This patch enables compressed input sections on big-endian targets by
checking the target endianness and selecting an appropriate `Chdr`
structure.

Fixes PR51369

Differential Revision: https://reviews.llvm.org/D107635
This commit is contained in:
Simon Atanasyan 2021-08-06 13:29:47 +03:00
parent 4c2e01232c
commit c6ebc651b6
4 changed files with 32 additions and 27 deletions

View File

@ -88,7 +88,22 @@ InputSectionBase::InputSectionBase(InputFile *file, uint64_t flags,
if (!zlib::isAvailable())
error(toString(file) + ": contains a compressed section, " +
"but zlib is not available");
parseCompressedHeader();
switch (config->ekind) {
case ELF32LEKind:
parseCompressedHeader<ELF32LE>();
break;
case ELF32BEKind:
parseCompressedHeader<ELF32BE>();
break;
case ELF64LEKind:
parseCompressedHeader<ELF64LE>();
break;
case ELF64BEKind:
parseCompressedHeader<ELF64BE>();
break;
default:
llvm_unreachable("unknown ELFT");
}
}
}
@ -210,10 +225,7 @@ OutputSection *SectionBase::getOutputSection() {
// When a section is compressed, `rawData` consists with a header followed
// by zlib-compressed data. This function parses a header to initialize
// `uncompressedSize` member and remove the header from `rawData`.
void InputSectionBase::parseCompressedHeader() {
using Chdr64 = typename ELF64LE::Chdr;
using Chdr32 = typename ELF32LE::Chdr;
template <typename ELFT> void InputSectionBase::parseCompressedHeader() {
// Old-style header
if (name.startswith(".zdebug")) {
if (!toStringRef(rawData).startswith("ZLIB")) {
@ -239,32 +251,13 @@ void InputSectionBase::parseCompressedHeader() {
assert(flags & SHF_COMPRESSED);
flags &= ~(uint64_t)SHF_COMPRESSED;
// New-style 64-bit header
if (config->is64) {
if (rawData.size() < sizeof(Chdr64)) {
error(toString(this) + ": corrupted compressed section");
return;
}
auto *hdr = reinterpret_cast<const Chdr64 *>(rawData.data());
if (hdr->ch_type != ELFCOMPRESS_ZLIB) {
error(toString(this) + ": unsupported compression type");
return;
}
uncompressedSize = hdr->ch_size;
alignment = std::max<uint32_t>(hdr->ch_addralign, 1);
rawData = rawData.slice(sizeof(*hdr));
return;
}
// New-style 32-bit header
if (rawData.size() < sizeof(Chdr32)) {
// New-style header
if (rawData.size() < sizeof(typename ELFT::Chdr)) {
error(toString(this) + ": corrupted compressed section");
return;
}
auto *hdr = reinterpret_cast<const Chdr32 *>(rawData.data());
auto *hdr = reinterpret_cast<const typename ELFT::Chdr *>(rawData.data());
if (hdr->ch_type != ELFCOMPRESS_ZLIB) {
error(toString(this) + ": unsupported compression type");
return;

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@ -238,6 +238,7 @@ public:
}
protected:
template <typename ELFT>
void parseCompressedHeader();
void uncompress() const;

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@ -3,6 +3,9 @@
# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
# RUN: not ld.lld %t.o -o /dev/null -shared 2>&1 | FileCheck %s
# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-unknown %s -o %t-be.o
# RUN: not ld.lld %t-be.o -o /dev/null -shared 2>&1 | FileCheck %s
## Check we are able to report zlib uncompress errors.
# CHECK: error: {{.*}}.o:(.debug_str): uncompress failed: zlib error: Z_DATA_ERROR

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@ -1,7 +1,9 @@
# REQUIRES: zlib, x86
# RUN: llvm-mc -compress-debug-sections=zlib -filetype=obj -triple=x86_64-unknown-linux %s -o %t
# RUN: llvm-mc -compress-debug-sections=zlib -filetype=obj -triple=powerpc64-unknown-unknown %s -o %t-be
# RUN: llvm-readobj --sections %t | FileCheck -check-prefix=ZLIB %s
# RUN: llvm-readobj --sections %t-be | FileCheck -check-prefix=ZLIB %s
# ZLIB: Section {
# ZLIB: Index: 2
# ZLIB: Name: .debug_str
@ -21,7 +23,9 @@
# ZLIB-NEXT: }
# RUN: llvm-mc -compress-debug-sections=zlib-gnu -filetype=obj -triple=x86_64-unknown-linux %s -o %t2
# RUN: llvm-mc -compress-debug-sections=zlib-gnu -filetype=obj -triple=powerpc64-unknown-unknown %s -o %t2-be
# RUN: llvm-readobj --sections %t2 | FileCheck -check-prefix=GNU %s
# RUN: llvm-readobj --sections %t2-be | FileCheck -check-prefix=GNU %s
# GNU: Section {
# GNU: Index: 2
# GNU: Name: .zdebug_str
@ -41,9 +45,13 @@
# RUN: ld.lld --hash-style=sysv %t -o %t.so -shared
# RUN: llvm-readobj --sections --section-data %t.so | FileCheck -check-prefix=DATA %s
# RUN: ld.lld --hash-style=sysv %t-be -o %t-be.so -shared
# RUN: llvm-readobj --sections --section-data %t-be.so | FileCheck -check-prefix=DATA %s
# RUN: ld.lld --hash-style=sysv %t2 -o %t2.so -shared
# RUN: llvm-readobj --sections --section-data %t2.so | FileCheck -check-prefix=DATA %s
# RUN: ld.lld --hash-style=sysv %t2-be -o %t2-be.so -shared
# RUN: llvm-readobj --sections --section-data %t2-be.so | FileCheck -check-prefix=DATA %s
# DATA: Section {
# DATA: Index: 6