[lldb][ELF] Read symbols from .gnu_debugdata sect.

Summary:
If the .symtab section is stripped from the binary it might be that
there's a .gnu_debugdata section which contains a smaller .symtab in
order to provide enough information to create a backtrace with function
names or to set and hit a breakpoint on a function name.

This change looks for a .gnu_debugdata section in the ELF object file.
The .gnu_debugdata section contains a xz-compressed ELF file with a
.symtab section inside. Symbols from that compressed .symtab section
are merged with the main object file's .dynsym symbols (if any).
In addition we always load the .dynsym even if there's a .symtab
section.

For example, the Fedora and RHEL operating systems strip their binaries
but keep a .gnu_debugdata section. While gdb already can read this
section, LLDB until this patch couldn't. To test this patch on a
Fedora or RHEL operating system, try to set a breakpoint on the "help"
symbol in the "zip" binary. Before this patch, only GDB can set this
breakpoint; now LLDB also can do so without installing extra debug
symbols:

    lldb /usr/bin/zip -b -o "b help" -o "r" -o "bt" -- -h

The above line runs LLDB in batch mode and on the "/usr/bin/zip -h"
target:

    (lldb) target create "/usr/bin/zip"
    Current executable set to '/usr/bin/zip' (x86_64).
    (lldb) settings set -- target.run-args  "-h"

Before the program starts, we set a breakpoint on the "help" symbol:

    (lldb) b help
    Breakpoint 1: where = zip`help, address = 0x00000000004093b0

Once the program is run and has hit the breakpoint we ask for a
backtrace:

    (lldb) r
    Process 10073 stopped
    * thread #1, name = 'zip', stop reason = breakpoint 1.1
        frame #0: 0x00000000004093b0 zip`help
    zip`help:
    ->  0x4093b0 <+0>:  pushq  %r12
        0x4093b2 <+2>:  movq   0x2af5f(%rip), %rsi       ;  + 4056
        0x4093b9 <+9>:  movl   $0x1, %edi
        0x4093be <+14>: xorl   %eax, %eax

    Process 10073 launched: '/usr/bin/zip' (x86_64)
    (lldb) bt
    * thread #1, name = 'zip', stop reason = breakpoint 1.1
      * frame #0: 0x00000000004093b0 zip`help
        frame #1: 0x0000000000403970 zip`main + 3248
        frame #2: 0x00007ffff7d8bf33 libc.so.6`__libc_start_main + 243
        frame #3: 0x0000000000408cee zip`_start + 46

In order to support the .gnu_debugdata section, one has to have LZMA
development headers installed. The CMake section, that controls this
part looks for the LZMA headers and enables .gnu_debugdata support by
default if they are found; otherwise or if explicitly requested, the
minidebuginfo support is disabled.

GDB supports the "mini debuginfo" section .gnu_debugdata since v7.6
(2013).

Reviewers: espindola, labath, jankratochvil, alexshap

Reviewed By: labath

Subscribers: rnkovacs, wuzish, shafik, emaste, mgorny, arichardson, hiraditya, MaskRay, lldb-commits

Tags: #lldb, #llvm

Differential Revision: https://reviews.llvm.org/D66791

llvm-svn: 373891
This commit is contained in:
Konrad Kleine 2019-10-07 10:32:16 +00:00
parent 5ce8c39149
commit 2c082b4827
15 changed files with 481 additions and 8 deletions

View File

@ -1,5 +1,6 @@
include(CheckCXXSymbolExists)
include(CheckTypeSize)
include(CMakeDependentOption)
set(LLDB_PROJECT_ROOT ${CMAKE_CURRENT_SOURCE_DIR})
set(LLDB_SOURCE_ROOT "${CMAKE_CURRENT_SOURCE_DIR}/source")
@ -384,6 +385,13 @@ endif()
set(LLDB_VERSION "${LLDB_VERSION_MAJOR}.${LLDB_VERSION_MINOR}.${LLDB_VERSION_PATCH}${LLDB_VERSION_SUFFIX}")
message(STATUS "LLDB version: ${LLDB_VERSION}")
find_package(LibLZMA)
cmake_dependent_option(LLDB_ENABLE_LZMA "Support LZMA compression" ON "LIBLZMA_FOUND" OFF)
if (LLDB_ENABLE_LZMA)
include_directories(${LIBLZMA_INCLUDE_DIRS})
endif()
llvm_canonicalize_cmake_booleans(LLDB_ENABLE_LZMA)
include_directories(BEFORE
${CMAKE_CURRENT_BINARY_DIR}/include
${CMAKE_CURRENT_SOURCE_DIR}/include

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@ -35,4 +35,6 @@
#cmakedefine HAVE_LIBCOMPRESSION
#endif
#cmakedefine01 LLDB_ENABLE_LZMA
#endif // #ifndef LLDB_HOST_CONFIG_H

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@ -0,0 +1,34 @@
//===-- LZMA.h --------------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef liblldb_Host_LZMA_h_
#define liblldb_Host_LZMA_h_
#include "llvm/ADT/ArrayRef.h"
namespace llvm {
class Error;
} // End of namespace llvm
namespace lldb_private {
namespace lzma {
bool isAvailable();
llvm::Expected<uint64_t>
getUncompressedSize(llvm::ArrayRef<uint8_t> InputBuffer);
llvm::Error uncompress(llvm::ArrayRef<uint8_t> InputBuffer,
llvm::SmallVectorImpl<uint8_t> &Uncompressed);
} // End of namespace lzma
} // End of namespace lldb_private
#endif // liblldb_Host_LZMA_h_

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@ -56,9 +56,11 @@ list(APPEND LLDB_TEST_DEPS
lli
llvm-config
llvm-dwarfdump
llvm-nm
llvm-mc
llvm-objcopy
llvm-readobj
llvm-strip
)
if(TARGET lld)

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@ -0,0 +1,12 @@
// This function will be embedded within the .symtab section of the
// .gnu_debugdata section.
int multiplyByFour(int num) { return num * 4; }
// This function will be embedded within the .dynsym section of the main binary.
int multiplyByThree(int num) { return num * 3; }
int main(int argc, char *argv[]) {
int x = multiplyByThree(argc);
int y = multiplyByFour(x);
return y;
}

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@ -0,0 +1,29 @@
# REQUIRES: lzma
# This test checks that an error occurs when a corrupted
# .gnu_debugdata section is trying to be xz uncompressed.
# RUN: yaml2obj %s > %t.obj
# TODO(kwk): once yaml2obj doesn't auto-generate a .symtab section
# when there's none in YAML, remove the following line:
# RUN: llvm-objcopy --remove-section=.symtab %t.obj
# RUN: %lldb -b -o 'image dump symtab' %t.obj 2>&1 | FileCheck %s
# CHECK: warning: (x86_64) {{.*}}.obj An error occurred while decompression the section .gnu_debugdata: lzma_stream_buffer_decode()=lzma error: LZMA_DATA_ERROR
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_EXEC
Machine: EM_X86_64
Entry: 0x00000000004004C0
Sections:
- Name: .gnu_debugdata
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content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
...

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@ -0,0 +1,26 @@
# REQUIRES: lzma
# RUN: yaml2obj %s > %t.obj
# TODO(kwk): once yaml2obj doesn't auto-generate a .symtab section
# when there's none in YAML, remove the following line:
# RUN: llvm-objcopy --remove-section=.symtab %t.obj
# RUN: %lldb -b -o 'image dump symtab' %t.obj | FileCheck %s
# CHECK: [ 0] 1 X Code 0x00000000004005b0 0x000000000000000f 0x00000012 multiplyByFour
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_EXEC
Machine: EM_X86_64
Entry: 0x00000000004004C0
Sections:
- Name: .gnu_debugdata
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content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
...

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@ -0,0 +1,29 @@
# REQUIRES: !lzma
# This test checks that a warning is printed when we're trying
# to decompress a .gnu_debugdata section when no LZMA support was compiled in.
# RUN: yaml2obj %s > %t.obj
# TODO(kwk): once yaml2obj doesn't auto-generate a .symtab section
# when there's none in YAML, remove the following line:
# RUN: llvm-objcopy --remove-section=.symtab %t.obj
# RUN: %lldb -b -o 'image dump symtab' %t.obj 2>&1 | FileCheck %s
# CHECK: warning: (x86_64) {{.*}}.obj No LZMA support found for reading .gnu_debugdata section
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_EXEC
Machine: EM_X86_64
Entry: 0x00000000004004C0
Sections:
- Name: .gnu_debugdata
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
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...

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@ -0,0 +1,86 @@
# REQUIRES: system-linux, lzma, xz
# We want to keep the symbol "multiplyByThree" in the .dynamic section and not
# have it put the default .symtab section.
# RUN: echo "{multiplyByThree;};" > %T/dynmic-symbols.txt
# RUN: %clang -Wl,--dynamic-list=%T/dynmic-symbols.txt -g -o %t.binary %p/Inputs/minidebuginfo-main.c
# The following section is adapted from GDB's official documentation:
# http://sourceware.org/gdb/current/onlinedocs/gdb/MiniDebugInfo.html#MiniDebugInfo
# Extract the dynamic symbols from the main binary, there is no need
# to also have these in the normal symbol table.
# IGNORE: llvm-nm -D %t.binary --format=posix --defined-only | awk '{ print $1 }' | sort > %t.dynsyms
# Extract all the text (i.e. function) symbols from the debuginfo.
# (Note that we actually also accept "D" symbols, for the benefit
# of platforms like PowerPC64 that use function descriptors.)
# IGNORE: llvm-nm %t.binary --format=posix --defined-only | awk '{ if ($2 == "T" || $2 == "t" || $2 == "D") print $1 }' | sort > %t.funcsyms
# Keep all the function symbols not already in the dynamic symbol
# table.
# IGNORE: comm -13 %t.dynsyms %t.funcsyms > %t.keep_symbols
# The result of the preceeding command can be preprocessed in %p/Inputs/minidebuginfo.keep_symbols
# because we know what symbol to keep.
# RUN: echo "multiplyByFour" > %p/Inputs/minidebuginfo.keep_symbols
# Separate full debug info into debug binary.
# RUN: llvm-objcopy --only-keep-debug %t.binary %t.debug
# Copy the full debuginfo, keeping only a minimal set of symbols and
# removing some unnecessary sections.
# RUN: llvm-objcopy -S --remove-section .gdb_index --remove-section .comment --keep-symbols=%p/Inputs/minidebuginfo.keep_symbols %t.debug %t.mini_debuginfo
# This command is not from the GDB manual but it slims down embedded minidebug
# info. On top if that, it ensures that we only have the multiplyByThree symbol
# in the .dynsym section of the main binary.
# RUN: llvm-objcopy --remove-section=.rela.dyn --remove-section=.gnu.version --remove-section=.gnu.hash --remove-section=.dynsym %t.mini_debuginfo
# Drop the full debug info from the original binary.
# RUN: llvm-strip --strip-all -R .comment %t.binary
# Inject the compressed data into the .gnu_debugdata section of the
# original binary.
# RUN: xz --force --keep %t.mini_debuginfo
# RUN: llvm-objcopy --add-section .gnu_debugdata=%t.mini_debuginfo.xz %t.binary
# Now run the binary and see that we can set and hit a breakpoint
# from within the .dynsym section (multiplyByThree) and one from
# the .symtab section embedded in the .gnu_debugdata section (multiplyByFour).
# RUN: %lldb -b -o 'b multiplyByThree' -o 'b multiplyByFour' -o 'run' -o 'continue' -o 'breakpoint list -v' %t.binary | FileCheck %s
# CHECK: (lldb) b multiplyByThree
# CHECK-NEXT: Breakpoint 1: where = minidebuginfo-set-and-hit-breakpoint.test.tmp.binary`multiplyByThree, address = 0x{{.*}}
# CHECK: (lldb) b multiplyByFour
# CHECK-NEXT: Breakpoint 2: where = minidebuginfo-set-and-hit-breakpoint.test.tmp.binary`multiplyByFour, address = 0x{{.*}}
# CHECK: * thread #1, name = 'minidebuginfo-s', stop reason = breakpoint 1.1
# CHECK: * thread #1, name = 'minidebuginfo-s', stop reason = breakpoint 2.1
# CHECK: (lldb) breakpoint list -v
# CHECK-NEXT: Current breakpoints:
# CHECK-NEXT: 1: name = 'multiplyByThree'
# CHECK-NEXT: 1.1:
# CHECK-NEXT: module = {{.*}}/minidebuginfo-set-and-hit-breakpoint.test.tmp.binary
# CHECK-NEXT: symbol = multiplyByThree
# CHECK-NEXT: address = 0x{{.*}}
# CHECK-NEXT: resolved = true
# CHECK-NEXT: hit count = 1
# CHECK: 2: name = 'multiplyByFour'
# CHECK-NEXT: 2.1:
# CHECK-NEXT: module = {{.*}}/minidebuginfo-set-and-hit-breakpoint.test.tmp.binary
# CHECK-NEXT: symbol = multiplyByFour
# CHECK-NEXT: address = 0x{{.*}}
# CHECK-NEXT: resolved = true
# CHECK-NEXT: hit count = 1

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@ -11,6 +11,7 @@ import lit.formats
from lit.llvm import llvm_config
from lit.llvm.subst import FindTool
from lit.llvm.subst import ToolSubst
from distutils.spawn import find_executable
site.addsitedir(os.path.dirname(__file__))
from helper import toolchain
@ -98,3 +99,9 @@ if 'native' in config.available_features:
if not config.lldb_disable_python:
config.available_features.add('python')
if config.lldb_enable_lzma:
config.available_features.add('lzma')
if find_executable('xz') != None:
config.available_features.add('xz')

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@ -15,6 +15,7 @@ config.lldb_lit_tools_dir = r"@LLDB_LIT_TOOLS_DIR@"
config.target_triple = "@TARGET_TRIPLE@"
config.python_executable = "@PYTHON_EXECUTABLE@"
config.have_zlib = @LLVM_ENABLE_ZLIB@
config.lldb_enable_lzma = @LLDB_ENABLE_LZMA@
config.host_triple = "@LLVM_HOST_TRIPLE@"
config.lldb_bitness = 64 if @LLDB_IS_64_BITS@ else 32
config.lldb_disable_python = @LLDB_DISABLE_PYTHON@

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@ -29,6 +29,7 @@ add_host_subdirectory(common
common/HostProcess.cpp
common/HostThread.cpp
common/LockFileBase.cpp
common/LZMA.cpp
common/MainLoop.cpp
common/MonitoringProcessLauncher.cpp
common/NativeProcessProtocol.cpp
@ -157,6 +158,9 @@ endif()
if (NOT LLDB_DISABLE_LIBEDIT)
list(APPEND EXTRA_LIBS ${libedit_LIBRARIES})
endif()
if (LLDB_ENABLE_LZMA)
list(APPEND EXTRA_LIBS ${LIBLZMA_LIBRARIES})
endif()
if (NOT LLDB_DISABLE_LIBEDIT)
list(APPEND LLDB_LIBEDIT_LIBS ${libedit_LIBRARIES})

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@ -0,0 +1,146 @@
//===-- LZMA.cpp ------------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Host/Config.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#if LLDB_ENABLE_LZMA
#include <lzma.h>
#endif // LLDB_ENABLE_LZMA
namespace lldb_private {
namespace lzma {
#if !LLDB_ENABLE_LZMA
bool isAvailable() { return false; }
llvm::Expected<uint64_t>
getUncompressedSize(llvm::ArrayRef<uint8_t> InputBuffer) {
llvm_unreachable("lzma::getUncompressedSize is unavailable");
}
llvm::Error uncompress(llvm::ArrayRef<uint8_t> InputBuffer,
llvm::SmallVectorImpl<uint8_t> &Uncompressed) {
llvm_unreachable("lzma::uncompress is unavailable");
}
#else // LLDB_ENABLE_LZMA
bool isAvailable() { return true; }
static const char *convertLZMACodeToString(lzma_ret Code) {
switch (Code) {
case LZMA_STREAM_END:
return "lzma error: LZMA_STREAM_END";
case LZMA_NO_CHECK:
return "lzma error: LZMA_NO_CHECK";
case LZMA_UNSUPPORTED_CHECK:
return "lzma error: LZMA_UNSUPPORTED_CHECK";
case LZMA_GET_CHECK:
return "lzma error: LZMA_GET_CHECK";
case LZMA_MEM_ERROR:
return "lzma error: LZMA_MEM_ERROR";
case LZMA_MEMLIMIT_ERROR:
return "lzma error: LZMA_MEMLIMIT_ERROR";
case LZMA_FORMAT_ERROR:
return "lzma error: LZMA_FORMAT_ERROR";
case LZMA_OPTIONS_ERROR:
return "lzma error: LZMA_OPTIONS_ERROR";
case LZMA_DATA_ERROR:
return "lzma error: LZMA_DATA_ERROR";
case LZMA_BUF_ERROR:
return "lzma error: LZMA_BUF_ERROR";
case LZMA_PROG_ERROR:
return "lzma error: LZMA_PROG_ERROR";
default:
llvm_unreachable("unknown or unexpected lzma status code");
}
}
llvm::Expected<uint64_t>
getUncompressedSize(llvm::ArrayRef<uint8_t> InputBuffer) {
lzma_stream_flags opts{};
if (InputBuffer.size() < LZMA_STREAM_HEADER_SIZE) {
return llvm::createStringError(
llvm::inconvertibleErrorCode(),
"size of xz-compressed blob (%lu bytes) is smaller than the "
"LZMA_STREAM_HEADER_SIZE (%lu bytes)",
InputBuffer.size(), LZMA_STREAM_HEADER_SIZE);
}
// Decode xz footer.
lzma_ret xzerr = lzma_stream_footer_decode(
&opts, InputBuffer.data() + InputBuffer.size() - LZMA_STREAM_HEADER_SIZE);
if (xzerr != LZMA_OK) {
return llvm::createStringError(llvm::inconvertibleErrorCode(),
"lzma_stream_footer_decode()=%s",
convertLZMACodeToString(xzerr));
}
if (InputBuffer.size() < (opts.backward_size + LZMA_STREAM_HEADER_SIZE)) {
return llvm::createStringError(
llvm::inconvertibleErrorCode(),
"xz-compressed buffer size (%lu bytes) too small (required at "
"least %lu bytes) ",
InputBuffer.size(), (opts.backward_size + LZMA_STREAM_HEADER_SIZE));
}
// Decode xz index.
lzma_index *xzindex;
uint64_t memlimit(UINT64_MAX);
size_t inpos = 0;
xzerr =
lzma_index_buffer_decode(&xzindex, &memlimit, nullptr,
InputBuffer.data() + InputBuffer.size() -
LZMA_STREAM_HEADER_SIZE - opts.backward_size,
&inpos, InputBuffer.size());
if (xzerr != LZMA_OK) {
return llvm::createStringError(llvm::inconvertibleErrorCode(),
"lzma_index_buffer_decode()=%s",
convertLZMACodeToString(xzerr));
}
// Get size of uncompressed file to construct an in-memory buffer of the
// same size on the calling end (if needed).
uint64_t uncompressedSize = lzma_index_uncompressed_size(xzindex);
// Deallocate xz index as it is no longer needed.
lzma_index_end(xzindex, nullptr);
return uncompressedSize;
}
llvm::Error uncompress(llvm::ArrayRef<uint8_t> InputBuffer,
llvm::SmallVectorImpl<uint8_t> &Uncompressed) {
llvm::Expected<uint64_t> uncompressedSize = getUncompressedSize(InputBuffer);
if (auto err = uncompressedSize.takeError())
return err;
Uncompressed.resize(*uncompressedSize);
// Decompress xz buffer to buffer.
uint64_t memlimit = UINT64_MAX;
size_t inpos = 0;
size_t outpos = 0;
lzma_ret ret = lzma_stream_buffer_decode(
&memlimit, 0, nullptr, InputBuffer.data(), &inpos, InputBuffer.size(),
Uncompressed.data(), &outpos, Uncompressed.size());
if (ret != LZMA_OK) {
return llvm::createStringError(llvm::inconvertibleErrorCode(),
"lzma_stream_buffer_decode()=%s",
convertLZMACodeToString(ret));
}
return llvm::Error::success();
}
#endif // LLDB_ENABLE_LZMA
} // end of namespace lzma
} // namespace lldb_private

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@ -18,6 +18,7 @@
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Section.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/LZMA.h"
#include "lldb/Symbol/DWARFCallFrameInfo.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Target/SectionLoadList.h"
@ -1842,6 +1843,70 @@ void ObjectFileELF::CreateSections(SectionList &unified_section_list) {
// unified section list.
if (GetType() != eTypeDebugInfo)
unified_section_list = *m_sections_up;
// If there's a .gnu_debugdata section, we'll try to read the .symtab that's
// embedded in there and replace the one in the original object file (if any).
// If there's none in the orignal object file, we add it to it.
if (auto gdd_obj_file = GetGnuDebugDataObjectFile()) {
if (auto gdd_objfile_section_list = gdd_obj_file->GetSectionList()) {
if (SectionSP symtab_section_sp =
gdd_objfile_section_list->FindSectionByType(
eSectionTypeELFSymbolTable, true)) {
SectionSP module_section_sp = unified_section_list.FindSectionByType(
eSectionTypeELFSymbolTable, true);
if (module_section_sp)
unified_section_list.ReplaceSection(module_section_sp->GetID(),
symtab_section_sp);
else
unified_section_list.AddSection(symtab_section_sp);
}
}
}
}
std::shared_ptr<ObjectFileELF> ObjectFileELF::GetGnuDebugDataObjectFile() {
if (m_gnu_debug_data_object_file != nullptr)
return m_gnu_debug_data_object_file;
SectionSP section =
GetSectionList()->FindSectionByName(ConstString(".gnu_debugdata"));
if (!section)
return nullptr;
if (!lldb_private::lzma::isAvailable()) {
GetModule()->ReportWarning(
"No LZMA support found for reading .gnu_debugdata section");
return nullptr;
}
// Uncompress the data
DataExtractor data;
section->GetSectionData(data);
llvm::SmallVector<uint8_t, 0> uncompressedData;
auto err = lldb_private::lzma::uncompress(data.GetData(), uncompressedData);
if (err) {
GetModule()->ReportWarning(
"An error occurred while decompression the section %s: %s",
section->GetName().AsCString(), llvm::toString(std::move(err)).c_str());
return nullptr;
}
// Construct ObjectFileELF object from decompressed buffer
DataBufferSP gdd_data_buf(
new DataBufferHeap(uncompressedData.data(), uncompressedData.size()));
auto fspec = GetFileSpec().CopyByAppendingPathComponent(
llvm::StringRef("gnu_debugdata"));
m_gnu_debug_data_object_file.reset(new ObjectFileELF(
GetModule(), gdd_data_buf, 0, &fspec, 0, gdd_data_buf->GetByteSize()));
// This line is essential; otherwise a breakpoint can be set but not hit.
m_gnu_debug_data_object_file->SetType(ObjectFile::eTypeDebugInfo);
ArchSpec spec = m_gnu_debug_data_object_file->GetArchitecture();
if (spec && m_gnu_debug_data_object_file->SetModulesArchitecture(spec))
return m_gnu_debug_data_object_file;
return nullptr;
}
// Find the arm/aarch64 mapping symbol character in the given symbol name.
@ -2649,19 +2714,29 @@ Symtab *ObjectFileELF::GetSymtab() {
// while the reverse is not necessarily true.
Section *symtab =
section_list->FindSectionByType(eSectionTypeELFSymbolTable, true).get();
if (!symtab) {
// The symtab section is non-allocable and can be stripped, so if it
// doesn't exist then use the dynsym section which should always be
// there.
symtab =
section_list->FindSectionByType(eSectionTypeELFDynamicSymbols, true)
.get();
}
if (symtab) {
m_symtab_up.reset(new Symtab(symtab->GetObjectFile()));
symbol_id += ParseSymbolTable(m_symtab_up.get(), symbol_id, symtab);
}
// The symtab section is non-allocable and can be stripped, while the
// .dynsym section which should always be always be there. To support the
// minidebuginfo case we parse .dynsym when there's a .gnu_debuginfo
// section, nomatter if .symtab was already parsed or not. This is because
// minidebuginfo normally removes the .symtab symbols which have their
// matching .dynsym counterparts.
if (!symtab ||
GetSectionList()->FindSectionByName(ConstString(".gnu_debugdata"))) {
Section *dynsym =
section_list->FindSectionByType(eSectionTypeELFDynamicSymbols, true)
.get();
if (dynsym) {
if (!m_symtab_up)
m_symtab_up.reset(new Symtab(dynsym->GetObjectFile()));
symbol_id += ParseSymbolTable(m_symtab_up.get(), symbol_id, dynsym);
}
}
// DT_JMPREL
// If present, this entry's d_ptr member holds the address of
// relocation

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@ -208,6 +208,10 @@ private:
/// Collection of symbols from the dynamic table.
DynamicSymbolColl m_dynamic_symbols;
/// Object file parsed from .gnu_debugdata section (\sa
/// GetGnuDebugDataObjectFile())
std::shared_ptr<ObjectFileELF> m_gnu_debug_data_object_file;
/// List of file specifications corresponding to the modules (shared
/// libraries) on which this object file depends.
mutable std::unique_ptr<lldb_private::FileSpecList> m_filespec_up;
@ -383,6 +387,14 @@ private:
lldb_private::UUID &uuid);
bool AnySegmentHasPhysicalAddress();
/// Takes the .gnu_debugdata and returns the decompressed object file that is
/// stored within that section.
///
/// \returns either the decompressed object file stored within the
/// .gnu_debugdata section or \c nullptr if an error occured or if there's no
/// section with that name.
std::shared_ptr<ObjectFileELF> GetGnuDebugDataObjectFile();
};
#endif // liblldb_ObjectFileELF_h_