kicad/thirdparty/sentry-native/external/libunwindstack-ndk/Unwinder.cpp

471 lines
14 KiB
C++

/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define _GNU_SOURCE 1
#include <elf.h>
#include <inttypes.h>
#include <stdint.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include <algorithm>
#include <memory>
#include <android-base/file.h>
#include <android-base/stringprintf.h>
#include <unwindstack/DexFiles.h>
#include <unwindstack/Elf.h>
#include <unwindstack/JitDebug.h>
#include <unwindstack/MapInfo.h>
#include <unwindstack/Maps.h>
#include <unwindstack/Memory.h>
#include <unwindstack/Unwinder.h>
#include "Check.h"
// Use the demangler from libc++.
extern "C" char* __cxa_demangle(const char*, char*, size_t*, int* status);
namespace unwindstack {
// Inject extra 'virtual' frame that represents the dex pc data.
// The dex pc is a magic register defined in the Mterp interpreter,
// and thus it will be restored/observed in the frame after it.
// Adding the dex frame first here will create something like:
// #7 pc 0015fa20 core.vdex java.util.Arrays.binarySearch+8
// #8 pc 006b1ba1 libartd.so ExecuteMterpImpl+14625
// #9 pc 0039a1ef libartd.so art::interpreter::Execute+719
void Unwinder::FillInDexFrame() {
size_t frame_num = frames_.size();
frames_.resize(frame_num + 1);
FrameData* frame = &frames_.at(frame_num);
frame->num = frame_num;
uint64_t dex_pc = regs_->dex_pc();
frame->pc = dex_pc;
frame->sp = regs_->sp();
frame->map_info = maps_->Find(dex_pc);
if (frame->map_info != nullptr) {
frame->rel_pc = dex_pc - frame->map_info->start();
// Initialize the load bias for this map so subsequent calls
// to GetLoadBias() will always return data.
frame->map_info->set_load_bias(0);
} else {
frame->rel_pc = dex_pc;
warnings_ |= WARNING_DEX_PC_NOT_IN_MAP;
return;
}
if (!resolve_names_) {
return;
}
#if defined(DEXFILE_SUPPORT)
if (dex_files_ == nullptr) {
return;
}
dex_files_->GetFunctionName(maps_, dex_pc, &frame->function_name, &frame->function_offset);
#endif
}
FrameData* Unwinder::FillInFrame(std::shared_ptr<MapInfo>& map_info, Elf* /*elf*/, uint64_t rel_pc,
uint64_t pc_adjustment) {
size_t frame_num = frames_.size();
frames_.resize(frame_num + 1);
FrameData* frame = &frames_.at(frame_num);
frame->num = frame_num;
frame->sp = regs_->sp();
frame->rel_pc = rel_pc - pc_adjustment;
frame->pc = regs_->pc() - pc_adjustment;
if (map_info == nullptr) {
// Nothing else to update.
return nullptr;
}
frame->map_info = map_info;
return frame;
}
static bool ShouldStop(const std::vector<std::string>* map_suffixes_to_ignore,
const std::string& map_name) {
if (map_suffixes_to_ignore == nullptr) {
return false;
}
auto pos = map_name.find_last_of('.');
if (pos == std::string::npos) {
return false;
}
return std::find(map_suffixes_to_ignore->begin(), map_suffixes_to_ignore->end(),
map_name.substr(pos + 1)) != map_suffixes_to_ignore->end();
}
void Unwinder::Unwind(const std::vector<std::string>* initial_map_names_to_skip,
const std::vector<std::string>* map_suffixes_to_ignore) {
CHECK(arch_ != ARCH_UNKNOWN);
ClearErrors();
frames_.clear();
// Clear any cached data from previous unwinds.
process_memory_->Clear();
if (maps_->Find(regs_->pc()) == nullptr) {
regs_->fallback_pc();
}
bool return_address_attempt = false;
bool adjust_pc = false;
for (; frames_.size() < max_frames_;) {
uint64_t cur_pc = regs_->pc();
uint64_t cur_sp = regs_->sp();
std::shared_ptr<MapInfo> map_info = maps_->Find(regs_->pc());
uint64_t pc_adjustment = 0;
uint64_t step_pc;
uint64_t rel_pc;
Elf* elf;
bool ignore_frame = false;
if (map_info == nullptr) {
step_pc = regs_->pc();
rel_pc = step_pc;
// If we get invalid map via return_address_attempt, don't hide error for the previous frame.
if (!return_address_attempt || last_error_.code == ERROR_NONE) {
last_error_.code = ERROR_INVALID_MAP;
last_error_.address = step_pc;
}
elf = nullptr;
} else {
ignore_frame =
initial_map_names_to_skip != nullptr &&
std::find(initial_map_names_to_skip->begin(), initial_map_names_to_skip->end(),
android::base::Basename(map_info->name())) != initial_map_names_to_skip->end();
if (!ignore_frame && ShouldStop(map_suffixes_to_ignore, map_info->name())) {
break;
}
elf = map_info->GetElf(process_memory_, arch_);
step_pc = regs_->pc();
rel_pc = elf->GetRelPc(step_pc, map_info.get());
// Everyone except elf data in gdb jit debug maps uses the relative pc.
if (!(map_info->flags() & MAPS_FLAGS_JIT_SYMFILE_MAP)) {
step_pc = rel_pc;
}
if (adjust_pc) {
pc_adjustment = GetPcAdjustment(rel_pc, elf, arch_);
} else {
pc_adjustment = 0;
}
step_pc -= pc_adjustment;
// If the pc is in an invalid elf file, try and get an Elf object
// using the jit debug information.
if (!elf->valid() && jit_debug_ != nullptr && (map_info->flags() & PROT_EXEC)) {
uint64_t adjusted_jit_pc = regs_->pc() - pc_adjustment;
Elf* jit_elf = jit_debug_->Find(maps_, adjusted_jit_pc);
if (jit_elf != nullptr) {
// The jit debug information requires a non relative adjusted pc.
step_pc = adjusted_jit_pc;
elf = jit_elf;
}
}
}
FrameData* frame = nullptr;
if (!ignore_frame) {
if (regs_->dex_pc() != 0) {
// Add a frame to represent the dex file.
FillInDexFrame();
// Clear the dex pc so that we don't repeat this frame later.
regs_->set_dex_pc(0);
// Make sure there is enough room for the real frame.
if (frames_.size() == max_frames_) {
last_error_.code = ERROR_MAX_FRAMES_EXCEEDED;
break;
}
}
frame = FillInFrame(map_info, elf, rel_pc, pc_adjustment);
// Once a frame is added, stop skipping frames.
initial_map_names_to_skip = nullptr;
}
adjust_pc = true;
bool stepped = false;
bool in_device_map = false;
bool finished = false;
if (map_info != nullptr) {
if (map_info->flags() & MAPS_FLAGS_DEVICE_MAP) {
// Do not stop here, fall through in case we are
// in the speculative unwind path and need to remove
// some of the speculative frames.
in_device_map = true;
} else {
auto sp_info = maps_->Find(regs_->sp());
if (sp_info != nullptr && sp_info->flags() & MAPS_FLAGS_DEVICE_MAP) {
// Do not stop here, fall through in case we are
// in the speculative unwind path and need to remove
// some of the speculative frames.
in_device_map = true;
} else {
bool is_signal_frame = false;
if (elf->StepIfSignalHandler(rel_pc, regs_, process_memory_.get())) {
stepped = true;
is_signal_frame = true;
} else if (elf->Step(step_pc, regs_, process_memory_.get(), &finished,
&is_signal_frame)) {
stepped = true;
}
if (is_signal_frame && frame != nullptr) {
// Need to adjust the relative pc because the signal handler
// pc should not be adjusted.
frame->rel_pc = rel_pc;
frame->pc += pc_adjustment;
step_pc = rel_pc;
}
elf->GetLastError(&last_error_);
}
}
}
if (frame != nullptr) {
if (!resolve_names_ ||
!elf->GetFunctionName(step_pc, &frame->function_name, &frame->function_offset)) {
frame->function_name = "";
frame->function_offset = 0;
}
}
if (finished) {
break;
}
if (!stepped) {
if (return_address_attempt) {
// Only remove the speculative frame if there are more than two frames
// or the pc in the first frame is in a valid map.
// This allows for a case where the code jumps into the middle of
// nowhere, but there is no other unwind information after that.
if (frames_.size() > 2 || (frames_.size() > 0 && maps_->Find(frames_[0].pc) != nullptr)) {
// Remove the speculative frame.
frames_.pop_back();
}
break;
} else if (in_device_map) {
// Do not attempt any other unwinding, pc or sp is in a device
// map.
break;
} else {
// Steping didn't work, try this secondary method.
if (!regs_->SetPcFromReturnAddress(process_memory_.get())) {
break;
}
return_address_attempt = true;
}
} else {
return_address_attempt = false;
if (max_frames_ == frames_.size()) {
last_error_.code = ERROR_MAX_FRAMES_EXCEEDED;
}
}
// If the pc and sp didn't change, then consider everything stopped.
if (cur_pc == regs_->pc() && cur_sp == regs_->sp()) {
last_error_.code = ERROR_REPEATED_FRAME;
break;
}
}
}
std::string Unwinder::FormatFrame(const FrameData& frame) const {
return FormatFrame(arch_, frame, display_build_id_);
}
std::string Unwinder::FormatFrame(ArchEnum arch, const FrameData& frame, bool display_build_id) {
std::string data;
if (ArchIs32Bit(arch)) {
data += android::base::StringPrintf(" #%02zu pc %08" PRIx64, frame.num, frame.rel_pc);
} else {
data += android::base::StringPrintf(" #%02zu pc %016" PRIx64, frame.num, frame.rel_pc);
}
auto map_info = frame.map_info;
if (map_info == nullptr) {
// No valid map associated with this frame.
data += " <unknown>";
} else if (!map_info->name().empty()) {
data += " ";
data += map_info->GetFullName();
} else {
data += android::base::StringPrintf(" <anonymous:%" PRIx64 ">", map_info->start());
}
if (map_info != nullptr && map_info->elf_start_offset() != 0) {
data += android::base::StringPrintf(" (offset 0x%" PRIx64 ")", map_info->elf_start_offset());
}
if (!frame.function_name.empty()) {
char* demangled_name = __cxa_demangle(frame.function_name.c_str(), nullptr, nullptr, nullptr);
if (demangled_name == nullptr) {
data += " (";
data += frame.function_name;
} else {
data += " (";
data += demangled_name;
free(demangled_name);
}
if (frame.function_offset != 0) {
data += android::base::StringPrintf("+%" PRId64, frame.function_offset);
}
data += ')';
}
if (map_info != nullptr && display_build_id) {
std::string build_id = map_info->GetPrintableBuildID();
if (!build_id.empty()) {
data += " (BuildId: " + build_id + ')';
}
}
return data;
}
std::string Unwinder::FormatFrame(size_t frame_num) const {
if (frame_num >= frames_.size()) {
return "";
}
return FormatFrame(arch_, frames_[frame_num], display_build_id_);
}
void Unwinder::SetJitDebug(JitDebug* jit_debug) {
jit_debug_ = jit_debug;
}
void Unwinder::SetDexFiles(DexFiles* dex_files) {
dex_files_ = dex_files;
}
bool UnwinderFromPid::Init() {
CHECK(arch_ != ARCH_UNKNOWN);
if (initted_) {
return true;
}
initted_ = true;
if (maps_ == nullptr) {
if (pid_ == getpid()) {
maps_ptr_.reset(new LocalMaps());
} else {
maps_ptr_.reset(new RemoteMaps(pid_));
}
if (!maps_ptr_->Parse()) {
ClearErrors();
last_error_.code = ERROR_INVALID_MAP;
return false;
}
maps_ = maps_ptr_.get();
}
if (process_memory_ == nullptr) {
if (pid_ == getpid()) {
// Local unwind, so use thread cache to allow multiple threads
// to cache data even when multiple threads access the same object.
process_memory_ = Memory::CreateProcessMemoryThreadCached(pid_);
} else {
// Remote unwind should be safe to cache since the unwind will
// be occurring on a stopped process.
process_memory_ = Memory::CreateProcessMemoryCached(pid_);
}
}
jit_debug_ptr_ = CreateJitDebug(arch_, process_memory_);
jit_debug_ = jit_debug_ptr_.get();
SetJitDebug(jit_debug_);
#if defined(DEXFILE_SUPPORT)
dex_files_ptr_ = CreateDexFiles(arch_, process_memory_);
dex_files_ = dex_files_ptr_.get();
SetDexFiles(dex_files_);
#endif
return true;
}
void UnwinderFromPid::Unwind(const std::vector<std::string>* initial_map_names_to_skip,
const std::vector<std::string>* map_suffixes_to_ignore) {
if (!Init()) {
return;
}
Unwinder::Unwind(initial_map_names_to_skip, map_suffixes_to_ignore);
}
FrameData Unwinder::BuildFrameFromPcOnly(uint64_t pc, ArchEnum arch, Maps* maps,
JitDebug* jit_debug,
std::shared_ptr<Memory> process_memory,
bool resolve_names) {
FrameData frame;
std::shared_ptr<MapInfo> map_info = maps->Find(pc);
if (map_info == nullptr || arch == ARCH_UNKNOWN) {
frame.pc = pc;
frame.rel_pc = pc;
return frame;
}
Elf* elf = map_info->GetElf(process_memory, arch);
uint64_t relative_pc = elf->GetRelPc(pc, map_info.get());
uint64_t pc_adjustment = GetPcAdjustment(relative_pc, elf, arch);
relative_pc -= pc_adjustment;
// The debug PC may be different if the PC comes from the JIT.
uint64_t debug_pc = relative_pc;
// If we don't have a valid ELF file, check the JIT.
if (!elf->valid() && jit_debug != nullptr) {
uint64_t jit_pc = pc - pc_adjustment;
Elf* jit_elf = jit_debug->Find(maps, jit_pc);
if (jit_elf != nullptr) {
debug_pc = jit_pc;
elf = jit_elf;
}
}
// Copy all the things we need into the frame for symbolization.
frame.rel_pc = relative_pc;
frame.pc = pc - pc_adjustment;
frame.map_info = map_info;
if (!resolve_names ||
!elf->GetFunctionName(debug_pc, &frame.function_name, &frame.function_offset)) {
frame.function_name = "";
frame.function_offset = 0;
}
return frame;
}
FrameData Unwinder::BuildFrameFromPcOnly(uint64_t pc) {
return BuildFrameFromPcOnly(pc, arch_, maps_, jit_debug_, process_memory_, resolve_names_);
}
} // namespace unwindstack