Fix reading DW_AT_ranges in split dwarf.

Bug: b/280290608, chromium:1448979
Change-Id: I3f9e4c3d62b4c858238ccbbda0366926c306e27f
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/4568824
Reviewed-by: Joshua Peraza <jperaza@chromium.org>
This commit is contained in:
Zequan Wu 2023-05-25 15:40:44 -04:00 committed by Joshua Peraza
parent 6857c7c65f
commit 02fe1eef8e
7 changed files with 86 additions and 52 deletions

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@ -580,10 +580,10 @@ enum DwarfSectionId {
DW_SECT_TYPES = 2,
DW_SECT_ABBREV = 3,
DW_SECT_LINE = 4,
DW_SECT_LOC = 5,
DW_SECT_LOCLISTS = 5,
DW_SECT_STR_OFFSETS = 6,
DW_SECT_MACINFO = 7,
DW_SECT_MACRO = 8
DW_SECT_MACRO = 7,
DW_SECT_RNGLISTS = 8
};
// Source languages. These are values for DW_AT_language.

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@ -80,7 +80,7 @@ CompilationUnit::CompilationUnit(const string& path,
str_offsets_buffer_(NULL), str_offsets_buffer_length_(0),
addr_buffer_(NULL), addr_buffer_length_(0),
is_split_dwarf_(false), is_type_unit_(false), dwo_id_(0), dwo_name_(),
skeleton_dwo_id_(0), ranges_base_(0), addr_base_(0),
skeleton_dwo_id_(0), addr_base_(0),
str_offsets_base_(0), have_checked_for_dwp_(false),
should_process_split_dwarf_(false) {}
@ -91,16 +91,11 @@ CompilationUnit::CompilationUnit(const string& path,
// the executable file, and call it as if we were still
// processing the original compilation unit.
void CompilationUnit::SetSplitDwarf(const uint8_t* addr_buffer,
uint64_t addr_buffer_length,
void CompilationUnit::SetSplitDwarf(
uint64_t addr_base,
uint64_t ranges_base,
uint64_t dwo_id) {
is_split_dwarf_ = true;
addr_buffer_ = addr_buffer;
addr_buffer_length_ = addr_buffer_length;
addr_base_ = addr_base;
ranges_base_ = ranges_base;
skeleton_dwo_id_ = dwo_id;
}
@ -889,7 +884,9 @@ const uint8_t* CompilationUnit::ProcessDIE(uint64_t dieoffset,
// DW_AT_str_offsets_base or DW_AT_addr_base. If it does, that attribute must
// be found and processed before trying to process the other attributes;
// otherwise the string or address values will all come out incorrect.
if (abbrev.tag == DW_TAG_compile_unit && header_.version == 5) {
if ((abbrev.tag == DW_TAG_compile_unit ||
abbrev.tag == DW_TAG_skeleton_unit) &&
header_.version == 5) {
uint64_t dieoffset_copy = dieoffset;
const uint8_t* start_copy = start;
for (AttributeList::const_iterator i = abbrev.attributes.begin();
@ -1016,7 +1013,8 @@ bool CompilationUnit::ProcessSplitDwarf(std::string& split_file,
string debug_suffix(".debug");
dwp_path = path_;
size_t found = path_.rfind(debug_suffix);
if (found + debug_suffix.length() == path_.length())
if (found != string::npos &&
found + debug_suffix.length() == path_.length())
dwp_path = dwp_path.replace(found, debug_suffix.length(), dwp_suffix);
}
if (stat(dwp_path.c_str(), &statbuf) == 0) {
@ -1133,6 +1131,8 @@ void DwpReader::Initialize() {
info_data_ = elf_reader_->GetSectionByName(".debug_info.dwo", &info_size_);
str_offsets_data_ = elf_reader_->GetSectionByName(".debug_str_offsets.dwo",
&str_offsets_size_);
rnglist_data_ =
elf_reader_->GetSectionByName(".debug_rnglists.dwo", &rnglist_size_);
if (size_table_ >= cu_index_ + cu_index_size_) {
version_ = 0;
}
@ -1245,6 +1245,12 @@ void DwpReader::ReadDebugSectionsForCU(uint64_t dwo_id,
".debug_str_offsets",
std::make_pair(reinterpret_cast<const uint8_t*> (str_offsets_data_)
+ offset, size)));
} else if (section_id == DW_SECT_RNGLISTS) {
sections->insert(std::make_pair(
".debug_rnglists",
std::make_pair(
reinterpret_cast<const uint8_t*>(rnglist_data_) + offset,
size)));
}
}
sections->insert(std::make_pair(
@ -1830,6 +1836,11 @@ bool RangeListReader::ReadRanges(enum DwarfForm form, uint64_t data) {
return ReadDebugRngList(data);
}
} else if (form == DW_FORM_rnglistx) {
if (cu_info_->ranges_base_ == 0) {
// In split dwarf, there's no DW_AT_rnglists_base attribute, range_base
// will just be the first byte after the header.
cu_info_->ranges_base_ = reader_->OffsetSize() == 4? 12: 20;
}
offset_array_ = cu_info_->ranges_base_;
uint64_t index_offset = reader_->OffsetSize() * data;
uint64_t range_list_offset =

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@ -469,8 +469,7 @@ class CompilationUnit {
// compilation unit. We also inherit the Dwarf2Handler from
// the executable file, and call it as if we were still
// processing the original compilation unit.
void SetSplitDwarf(const uint8_t* addr_buffer, uint64_t addr_buffer_length,
uint64_t addr_base, uint64_t ranges_base, uint64_t dwo_id);
void SetSplitDwarf(uint64_t addr_base, uint64_t dwo_id);
// Begin reading a Dwarf2 compilation unit, and calling the
// callbacks in the Dwarf2Handler
@ -493,7 +492,7 @@ class CompilationUnit {
uint64_t GetAddrBase() { return addr_base_; }
uint64_t GetRangeBase() { return ranges_base_; }
uint64_t GetLowPC() { return low_pc_; }
uint64_t GetDWOID() { return dwo_id_; }
@ -583,14 +582,8 @@ class CompilationUnit {
else if (attr == DW_AT_str_offsets_base) {
str_offsets_base_ = data;
}
else if (attr == DW_AT_GNU_ranges_base || attr == DW_AT_rnglists_base) {
ranges_base_ = data;
}
// TODO(yunlian): When we add DW_AT_ranges_base from DWARF-5,
// that base will apply to DW_AT_ranges attributes in the
// skeleton CU as well as in the .dwo/.dwp files.
else if (attr == DW_AT_ranges && is_split_dwarf_) {
data += ranges_base_;
else if (attr == DW_AT_low_pc) {
low_pc_ = data;
}
handler_->ProcessAttributeUnsigned(offset, attr, form, data);
}
@ -745,10 +738,6 @@ class CompilationUnit {
// from the skeleton CU.
uint64_t skeleton_dwo_id_;
// The value of the DW_AT_GNU_ranges_base or DW_AT_rnglists_base attribute,
// if any.
uint64_t ranges_base_;
// The value of the DW_AT_GNU_addr_base attribute, if any.
uint64_t addr_base_;
@ -762,9 +751,12 @@ class CompilationUnit {
std::unique_ptr<ElfReader> split_elf_reader_;
// DWP reader.
std::unique_ptr<DwpReader> dwp_reader_;
std::unique_ptr<DwpReader> dwp_reader_;
bool should_process_split_dwarf_;
bool should_process_split_dwarf_;
// The value of the DW_AT_low_pc attribute, if any.
uint64_t low_pc_;
};
// A Reader for a .dwp file. Supports the fetching of DWARF debug
@ -851,6 +843,8 @@ class DwpReader {
size_t info_size_;
const char* str_offsets_data_;
size_t str_offsets_size_;
const char* rnglist_data_;
size_t rnglist_size_;
};
// This class is a reader for DWARF's Call Frame Information. CFI

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@ -169,19 +169,23 @@ bool DwarfCUToModule::FileContext::IsUnhandledInterCUReference(
// parsing. This is for data shared across the CU's entire DIE tree,
// and parameters from the code invoking the CU parser.
struct DwarfCUToModule::CUContext {
CUContext(FileContext* file_context_arg, WarningReporter* reporter_arg,
RangesHandler* ranges_handler_arg)
CUContext(FileContext* file_context_arg,
WarningReporter* reporter_arg,
RangesHandler* ranges_handler_arg,
uint64_t low_pc,
uint64_t addr_base)
: version(0),
file_context(file_context_arg),
reporter(reporter_arg),
ranges_handler(ranges_handler_arg),
language(Language::CPlusPlus),
low_pc(0),
low_pc(low_pc),
high_pc(0),
ranges_form(DW_FORM_sec_offset),
ranges_data(0),
ranges_base(0),
str_offsets_base(0) { }
addr_base(addr_base),
str_offsets_base(0) {}
~CUContext() {
for (vector<Module::Function*>::iterator it = functions.begin();
@ -854,7 +858,7 @@ void DwarfCUToModule::FuncHandler::Finish() {
iter->second->name = name_;
}
if (!ranges_data_) {
if (low_pc_ && high_pc_) {
// Make high_pc_ an address, if it isn't already.
if (high_pc_form_ != DW_FORM_addr &&
high_pc_form_ != DW_FORM_GNU_addr_index &&
@ -868,7 +872,7 @@ void DwarfCUToModule::FuncHandler::Finish() {
Module::Range range(low_pc_, high_pc_ - low_pc_);
ranges.push_back(range);
} else {
} else if (ranges_data_) {
RangesHandler* ranges_handler = cu_context_->ranges_handler;
if (ranges_handler) {
RangeListReader::CURangesInfo cu_info;
@ -1069,10 +1073,16 @@ DwarfCUToModule::DwarfCUToModule(FileContext* file_context,
LineToModuleHandler* line_reader,
RangesHandler* ranges_handler,
WarningReporter* reporter,
bool handle_inline)
bool handle_inline,
uint64_t low_pc,
uint64_t addr_base)
: RootDIEHandler(handle_inline),
line_reader_(line_reader),
cu_context_(new CUContext(file_context, reporter, ranges_handler)),
cu_context_(new CUContext(file_context,
reporter,
ranges_handler,
low_pc,
addr_base)),
child_context_(new DIEContext()),
has_source_line_info_(false) {}

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@ -264,7 +264,9 @@ class DwarfCUToModule: public RootDIEHandler {
LineToModuleHandler* line_reader,
RangesHandler* ranges_handler,
WarningReporter* reporter,
bool handle_inline = false);
bool handle_inline = false,
uint64_t low_pc = 0,
uint64_t addr_base = 0);
~DwarfCUToModule();
void ProcessAttributeSigned(enum DwarfAttribute attr,

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@ -348,18 +348,27 @@ void StartProcessSplitDwarf(google_breakpad::CompilationUnit* reader,
return;
DwarfCUToModule::FileContext file_context(split_file, module,
handle_inter_cu_refs);
for (auto section : split_sections)
file_context.AddSectionToSectionMap(section.first, section.second.first,
section.second.second);
// Because DWP/DWO file doesn't have .debug_addr/.debug_line, its debug info
// will refer to .debug_addr/.debug_line in the main binary.
if (file_context.section_map().find(".debug_addr") ==
file_context.section_map().end())
file_context.AddSectionToSectionMap(".debug_addr", reader->GetAddrBuffer(),
reader->GetAddrBufferLen());
DumperRangesHandler ranges_handler(&split_byte_reader);
DumperLineToModule line_to_module(&split_byte_reader);
DwarfCUToModule::WarningReporter reporter(split_file, cu_offset);
DwarfCUToModule root_handler(&file_context, &line_to_module, &ranges_handler,
&reporter, handle_inline);
&reporter, handle_inline, reader->GetLowPC(),
reader->GetAddrBase());
google_breakpad::DIEDispatcher die_dispatcher(&root_handler);
google_breakpad::CompilationUnit split_reader(split_file, split_sections,
cu_offset, &split_byte_reader,
&die_dispatcher);
split_reader.SetSplitDwarf(reader->GetAddrBuffer(),
reader->GetAddrBufferLen(), reader->GetAddrBase(),
reader->GetRangeBase(), reader->GetDWOID());
google_breakpad::CompilationUnit split_reader(
split_file, file_context.section_map(), cu_offset, &split_byte_reader,
&die_dispatcher);
split_reader.SetSplitDwarf(reader->GetAddrBase(), reader->GetDWOID());
split_reader.Start();
// Normally, it won't happen unless we have transitive reference.
if (split_reader.ShouldProcessSplitDwarf()) {

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@ -439,18 +439,26 @@ void DumpSymbols::StartProcessSplitDwarf(
return;
DwarfCUToModule::FileContext file_context(split_file, module,
handle_inter_cu_refs);
for (auto section : split_sections)
file_context.AddSectionToSectionMap(section.first, section.second.first,
section.second.second);
// If DWP/DWO file doesn't have .debug_addr, its debug info will refer to
// .debug_addr in the main binary.
if (file_context.section_map().find(".debug_addr") ==
file_context.section_map().end())
file_context.AddSectionToSectionMap(".debug_addr", reader->GetAddrBuffer(),
reader->GetAddrBufferLen());
DumperRangesHandler ranges_handler(&split_byte_reader);
DumperLineToModule line_to_module(&split_byte_reader);
DwarfCUToModule::WarningReporter reporter(split_file, cu_offset);
DwarfCUToModule root_handler(&file_context, &line_to_module, &ranges_handler,
&reporter, handle_inline);
&reporter, handle_inline, reader->GetLowPC(),
reader->GetAddrBase());
google_breakpad::DIEDispatcher die_dispatcher(&root_handler);
google_breakpad::CompilationUnit split_reader(split_file, split_sections,
cu_offset, &split_byte_reader,
&die_dispatcher);
split_reader.SetSplitDwarf(reader->GetAddrBuffer(),
reader->GetAddrBufferLen(), reader->GetAddrBase(),
reader->GetRangeBase(), reader->GetDWOID());
google_breakpad::CompilationUnit split_reader(
split_file, file_context.section_map(), cu_offset, &split_byte_reader,
&die_dispatcher);
split_reader.SetSplitDwarf(reader->GetAddrBase(), reader->GetDWOID());
split_reader.Start();
// Normally, it won't happen unless we have transitive reference.
if (split_reader.ShouldProcessSplitDwarf()) {