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Add a relocation to ObjectFileELF::ApplyRelocations and a test
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Summary:
pcm files can end up being processed by lldb with relocations to be
made for the .debug_info section. When a R_AARCH64_ABS64 relocation
was required lldb would hit an `assert(false)` and die.

Add R_AARCH64_ABS64 relocations to the S+A 64 bit width code path. Add
a test for R_AARCH64_ABS64 and R_AARCH64_ABS32 .rela.debug_info
relocations in a pcm file.

Reviewers: sas, xiaobai, davide, javed.absar, espindola

Reviewed By: davide

Subscribers: labath, zturner, emaste, mgorny, arichardson, kristof.beyls

Differential Revision: https://reviews.llvm.org/D51566

llvm-svn: 346171
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@lanza
lanza committed Nov 5, 2018
1 parent def82a8 commit 6868d2d
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Showing 4 changed files with 252 additions and 3 deletions.
9 changes: 6 additions & 3 deletions lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
View file
Expand Up @@ -2703,6 +2703,7 @@ unsigned ObjectFileELF::ApplyRelocations(
}
} else {
switch (reloc_type(rel)) {
case R_AARCH64_ABS64:
case R_X86_64_64: {
symbol = symtab->FindSymbolByID(reloc_symbol(rel));
if (symbol) {
Expand All @@ -2722,13 +2723,15 @@ unsigned ObjectFileELF::ApplyRelocations(
if (symbol) {
addr_t value = symbol->GetAddressRef().GetFileAddress();
value += ELFRelocation::RelocAddend32(rel);
if ((reloc_type(rel) == R_X86_64_32 && (value <= UINT32_MAX)) ||
if ((reloc_type(rel) == R_X86_64_32 && (value > UINT32_MAX)) ||
(reloc_type(rel) == R_X86_64_32S &&
((int64_t)value <= INT32_MAX && (int64_t)value >= INT32_MIN)) ||
(reloc_type(rel) == R_AARCH64_ABS32 && (value <= UINT32_MAX))) {
((int64_t)value > INT32_MAX && (int64_t)value < INT32_MIN)) ||
(reloc_type(rel) == R_AARCH64_ABS32 &&
((int64_t)value > INT32_MAX && (int64_t)value < INT32_MIN))) {
Log *log =
lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_MODULES);
log->Printf("Failed to apply debug info relocations");
break;
}
uint32_t truncated_addr = (value & 0xFFFFFFFF);
DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
Expand Down
1 change: 1 addition & 0 deletions lldb/unittests/ObjectFile/ELF/CMakeLists.txt
View file
Expand Up @@ -13,6 +13,7 @@ add_definitions(-DYAML2OBJ="$<TARGET_FILE:yaml2obj>")

set(test_inputs
early-section-headers.so
debug-info-relocations.pcm.yaml
sections-resolve-consistently.yaml
)
add_unittest_inputs(ObjectFileELFTests "${test_inputs}")
183 changes: 183 additions & 0 deletions lldb/unittests/ObjectFile/ELF/Inputs/debug-info-relocations.pcm.yaml
View file
@@ -0,0 +1,183 @@
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_REL
Machine: EM_AARCH64
Sections:
- Name: .text
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
AddressAlign: 0x0000000000000004
Content: E0031B32C0035FD6
- Name: .debug_str
Type: SHT_PROGBITS
Flags: [ SHF_MERGE, SHF_STRINGS ]
AddressAlign: 0x0000000000000001
Content: 636C616E672076657273696F6E20362E302E312028746167732F52454C454153455F3630312F66696E616C2900726564756365642E68002F746D702F617364666173646673646661006600696E7400
- Name: .debug_abbrev
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: 011101250E1305030E10171B0EB44219110112060000022E00110112064018030E3A0B3B0B271949133F190000032400030E3E0B0B0B000000
- Name: .debug_info
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: 470000000400000000000801000000000C0000000000000000000000000000000000000000000800000002000000000000000008000000016F000000000102430000000300000000050400
- Name: .rela.debug_info
Type: SHT_RELA
Link: .symtab
AddressAlign: 0x0000000000000008
Info: .debug_info
Relocations:
- Offset: 0x0000000000000006
Symbol: .debug_abbrev
Type: R_AARCH64_ABS32
- Offset: 0x000000000000000C
Symbol: .debug_str
Type: R_AARCH64_ABS32
- Offset: 0x0000000000000012
Symbol: .debug_str
Type: R_AARCH64_ABS32
Addend: 45
- Offset: 0x0000000000000016
Symbol: .debug_line
Type: R_AARCH64_ABS32
- Offset: 0x000000000000001A
Symbol: .debug_str
Type: R_AARCH64_ABS32
Addend: 55
- Offset: 0x000000000000001E
Symbol: .text
Type: R_AARCH64_ABS64
- Offset: 0x000000000000002B
Symbol: .text
Type: R_AARCH64_ABS64
- Offset: 0x0000000000000039
Symbol: .debug_str
Type: R_AARCH64_ABS32
Addend: 73
- Offset: 0x0000000000000044
Symbol: .debug_str
Type: R_AARCH64_ABS32
Addend: 75
- Name: .debug_ranges
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: ''
- Name: .debug_macinfo
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: '00'
- Name: .debug_pubnames
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: 140000000200000000004B0000002A000000660000000000
- Name: .rela.debug_pubnames
Type: SHT_RELA
Link: .symtab
AddressAlign: 0x0000000000000008
Info: .debug_pubnames
Relocations:
- Offset: 0x0000000000000006
Symbol: .debug_info
Type: R_AARCH64_ABS32
- Name: .debug_pubtypes
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: 160000000200000000004B00000043000000696E740000000000
- Name: .rela.debug_pubtypes
Type: SHT_RELA
Link: .symtab
AddressAlign: 0x0000000000000008
Info: .debug_pubtypes
Relocations:
- Offset: 0x0000000000000006
Symbol: .debug_info
Type: R_AARCH64_ABS32
- Name: .comment
Type: SHT_PROGBITS
Flags: [ SHF_MERGE, SHF_STRINGS ]
AddressAlign: 0x0000000000000001
Content: 00636C616E672076657273696F6E20362E302E312028746167732F52454C454153455F3630312F66696E616C2900
- Name: .note.GNU-stack
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: ''
- Name: .debug_frame
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000008
Content: 14000000FFFFFFFF04000800017C1E0C1F00000000000000140000000000000000000000000000000800000000000000
- Name: .rela.debug_frame
Type: SHT_RELA
Link: .symtab
AddressAlign: 0x0000000000000008
Info: .debug_frame
Relocations:
- Offset: 0x000000000000001C
Symbol: .debug_frame
Type: R_AARCH64_ABS32
- Offset: 0x0000000000000020
Symbol: .text
Type: R_AARCH64_ABS64
- Name: .debug_line
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: 3C000000040021000000010101FB0E0D00010101010000000100000100726564756365642E68000000000000090200000000000000001305030A4B0204000101
- Name: .rela.debug_line
Type: SHT_RELA
Link: .symtab
AddressAlign: 0x0000000000000008
Info: .debug_line
Relocations:
- Offset: 0x000000000000002E
Symbol: .text
Type: R_AARCH64_ABS64
Symbols:
Local:
- Name: reduced.h
Type: STT_FILE
- Name: '$d.1'
Section: .debug_str
- Name: '$d.2'
Section: .debug_abbrev
- Name: '$d.3'
Section: .debug_info
- Name: '$d.4'
Section: .debug_macinfo
- Name: '$d.5'
Section: .debug_pubnames
- Name: '$d.6'
Section: .debug_pubtypes
- Name: '$d.7'
Section: .comment
- Name: '$d.8'
Section: .debug_frame
- Name: '$d.9'
Section: .debug_line
- Name: '$x.0'
Section: .text
- Name: .text
Type: STT_SECTION
Section: .text
- Name: .debug_str
Type: STT_SECTION
Section: .debug_str
- Name: .debug_abbrev
Type: STT_SECTION
Section: .debug_abbrev
- Name: .debug_info
Type: STT_SECTION
Section: .debug_info
- Name: .debug_frame
Type: STT_SECTION
Section: .debug_frame
- Name: .debug_line
Type: STT_SECTION
Section: .debug_line
Global:
- Name: f
Type: STT_FUNC
Section: .text
Size: 0x0000000000000008
DynamicSymbols:
...
62 changes: 62 additions & 0 deletions lldb/unittests/ObjectFile/ELF/TestObjectFileELF.cpp
View file
Expand Up @@ -16,6 +16,7 @@
#include "lldb/Core/Section.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Utility/DataBufferHeap.h"
#include "llvm/ADT/Optional.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/FileUtilities.h"
Expand Down Expand Up @@ -141,3 +142,64 @@ TEST_F(ObjectFileELFTest, GetModuleSpecifications_EarlySectionHeaders) {
Uuid.SetFromStringRef("1b8a73ac238390e32a7ff4ac8ebe4d6a41ecf5c9", 20);
EXPECT_EQ(Spec.GetUUID(), Uuid);
}

#define CHECK_ABS32(offset, addend) \
ASSERT_EQ((uint32_t)addend, *(uint32_t *)(bytes + offset))
#define CHECK_ABS64(offset, addend) \
ASSERT_EQ((uint64_t)addend, *(uint64_t *)(bytes + offset))

TEST_F(ObjectFileELFTest, TestAARCH64Relocations) {
std::string yaml = GetInputFilePath("debug-info-relocations.pcm.yaml");
llvm::SmallString<128> obj;
ASSERT_NO_ERROR(llvm::sys::fs::createTemporaryFile(
"debug-info-relocations-%%%%%%", "obj", obj));

llvm::FileRemover remover(obj);
llvm::StringRef args[] = {YAML2OBJ, yaml};
llvm::StringRef obj_ref = obj;
const llvm::Optional<llvm::StringRef> redirects[] = {llvm::None, obj_ref,
llvm::None};
ASSERT_EQ(0,
llvm::sys::ExecuteAndWait(YAML2OBJ, args, llvm::None, redirects));
uint64_t size;
ASSERT_NO_ERROR(llvm::sys::fs::file_size(obj, size));
ASSERT_GT(size, 0u);

ModuleSpec spec{FileSpec(obj)};
spec.GetSymbolFileSpec().SetFile(obj, FileSpec::Style::native);
auto module_sp = std::make_shared<Module>(spec);

auto objfile = static_cast<ObjectFileELF *>(module_sp->GetObjectFile());
SectionList *section_list = objfile->GetSectionList();
ASSERT_NE(nullptr, section_list);

auto debug_info_sp =
section_list->FindSectionByName(ConstString(".debug_info"));
ASSERT_NE(nullptr, debug_info_sp);
objfile->RelocateSection(debug_info_sp.get());

DataExtractor data;
// length of 0x10 is not needed but length 0x0 crashes
objfile->GetData(0x00, 0x10, data);
DataBufferSP &data_buffer_sp = data.GetSharedDataBuffer();
uint8_t *bytes = data_buffer_sp->GetBytes();

addr_t debug_info_offset = debug_info_sp->GetFileOffset();
bytes += debug_info_offset;

// Sanity check - The first byte from the yaml file is 0x47
ASSERT_EQ(0x47, *bytes);

// .rela.debug_info contains 9 relocations:
// 7 R_AARCH64_ABS32 - 2 R_AARCH64_ABS64
// None have a value. Four have addends.
CHECK_ABS32(0x6, 0);
CHECK_ABS32(0xC, 0);
CHECK_ABS32(0x12, 45);
CHECK_ABS32(0x16, 0);
CHECK_ABS32(0x1A, 55);
CHECK_ABS64(0x1E, 0);
CHECK_ABS64(0x2B, 0);
CHECK_ABS32(0x39, 73);
CHECK_ABS32(0x44, 75);
}

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