| /* |
| * 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/types.h> |
| #include <unistd.h> |
| |
| #include <algorithm> |
| |
| #include <android-base/stringprintf.h> |
| #include <android-base/strings.h> |
| |
| #include <demangle.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> |
| |
| #if !defined(NO_LIBDEXFILE_SUPPORT) |
| #include <unwindstack/DexFiles.h> |
| #endif |
| |
| 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(); |
| |
| MapInfo* info = maps_->Find(dex_pc); |
| if (info != nullptr) { |
| frame->map_start = info->start; |
| frame->map_end = info->end; |
| frame->map_elf_start_offset = info->elf_start_offset; |
| frame->map_exact_offset = info->offset; |
| frame->map_load_bias = info->load_bias; |
| frame->map_flags = info->flags; |
| if (resolve_names_) { |
| frame->map_name = info->name; |
| } |
| frame->rel_pc = dex_pc - info->start; |
| } else { |
| frame->rel_pc = dex_pc; |
| return; |
| } |
| |
| if (!resolve_names_) { |
| return; |
| } |
| |
| #if !defined(NO_LIBDEXFILE_SUPPORT) |
| if (dex_files_ == nullptr) { |
| return; |
| } |
| |
| dex_files_->GetMethodInformation(maps_, info, dex_pc, &frame->function_name, |
| &frame->function_offset); |
| #endif |
| } |
| |
| FrameData* Unwinder::FillInFrame(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; |
| } |
| |
| if (resolve_names_) { |
| frame->map_name = map_info->name; |
| if (embedded_soname_ && map_info->elf_start_offset != 0 && !frame->map_name.empty()) { |
| std::string soname = elf->GetSoname(); |
| if (!soname.empty()) { |
| frame->map_name += '!' + soname; |
| } |
| } |
| } |
| frame->map_elf_start_offset = map_info->elf_start_offset; |
| frame->map_exact_offset = map_info->offset; |
| frame->map_start = map_info->start; |
| frame->map_end = map_info->end; |
| frame->map_flags = map_info->flags; |
| frame->map_load_bias = elf->GetLoadBias(); |
| return frame; |
| } |
| |
| static bool ShouldStop(const std::vector<std::string>* map_suffixes_to_ignore, |
| 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) { |
| frames_.clear(); |
| last_error_.code = ERROR_NONE; |
| last_error_.address = 0; |
| elf_from_memory_not_file_ = false; |
| |
| ArchEnum arch = regs_->Arch(); |
| |
| 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(); |
| |
| MapInfo* map_info = maps_->Find(regs_->pc()); |
| uint64_t pc_adjustment = 0; |
| uint64_t step_pc; |
| uint64_t rel_pc; |
| Elf* elf; |
| if (map_info == nullptr) { |
| step_pc = regs_->pc(); |
| rel_pc = step_pc; |
| last_error_.code = ERROR_INVALID_MAP; |
| } else { |
| if (ShouldStop(map_suffixes_to_ignore, map_info->name)) { |
| break; |
| } |
| elf = map_info->GetElf(process_memory_, arch); |
| // If this elf is memory backed, and there is a valid file, then set |
| // an indicator that we couldn't open the file. |
| if (!elf_from_memory_not_file_ && map_info->memory_backed_elf && !map_info->name.empty() && |
| map_info->name[0] != '[' && !android::base::StartsWith(map_info->name, "/memfd:")) { |
| elf_from_memory_not_file_ = true; |
| } |
| step_pc = regs_->pc(); |
| rel_pc = elf->GetRelPc(step_pc, map_info); |
| // 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 = regs_->GetPcAdjustment(rel_pc, elf); |
| } 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) { |
| uint64_t adjusted_jit_pc = regs_->pc() - pc_adjustment; |
| Elf* jit_elf = jit_debug_->GetElf(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 (map_info == nullptr || initial_map_names_to_skip == nullptr || |
| std::find(initial_map_names_to_skip->begin(), initial_map_names_to_skip->end(), |
| basename(map_info->name.c_str())) == initial_map_names_to_skip->end()) { |
| 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 { |
| MapInfo* 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 { |
| if (elf->StepIfSignalHandler(rel_pc, regs_, process_memory_.get())) { |
| stepped = true; |
| if (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; |
| } |
| } else if (elf->Step(step_pc, regs_, process_memory_.get(), &finished)) { |
| stepped = true; |
| } |
| 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) { |
| std::string data; |
| if (regs_->Is32Bit()) { |
| 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); |
| } |
| |
| if (frame.map_start == frame.map_end) { |
| // No valid map associated with this frame. |
| data += " <unknown>"; |
| } else if (!frame.map_name.empty()) { |
| data += " " + frame.map_name; |
| } else { |
| data += android::base::StringPrintf(" <anonymous:%" PRIx64 ">", frame.map_start); |
| } |
| |
| if (frame.map_elf_start_offset != 0) { |
| data += android::base::StringPrintf(" (offset 0x%" PRIx64 ")", frame.map_elf_start_offset); |
| } |
| |
| if (!frame.function_name.empty()) { |
| data += " (" + demangle(frame.function_name.c_str()); |
| if (frame.function_offset != 0) { |
| data += android::base::StringPrintf("+%" PRId64, frame.function_offset); |
| } |
| data += ')'; |
| } |
| |
| MapInfo* map_info = maps_->Find(frame.map_start); |
| 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) { |
| if (frame_num >= frames_.size()) { |
| return ""; |
| } |
| return FormatFrame(frames_[frame_num]); |
| } |
| |
| void Unwinder::SetJitDebug(JitDebug* jit_debug, ArchEnum arch) { |
| jit_debug->SetArch(arch); |
| jit_debug_ = jit_debug; |
| } |
| |
| #if !defined(NO_LIBDEXFILE_SUPPORT) |
| void Unwinder::SetDexFiles(DexFiles* dex_files, ArchEnum arch) { |
| dex_files->SetArch(arch); |
| dex_files_ = dex_files; |
| } |
| #endif |
| |
| bool UnwinderFromPid::Init(ArchEnum arch) { |
| if (pid_ == getpid()) { |
| maps_ptr_.reset(new LocalMaps()); |
| } else { |
| maps_ptr_.reset(new RemoteMaps(pid_)); |
| } |
| if (!maps_ptr_->Parse()) { |
| return false; |
| } |
| maps_ = maps_ptr_.get(); |
| |
| process_memory_ = Memory::CreateProcessMemoryCached(pid_); |
| |
| jit_debug_ptr_.reset(new JitDebug(process_memory_)); |
| jit_debug_ = jit_debug_ptr_.get(); |
| SetJitDebug(jit_debug_, arch); |
| #if !defined(NO_LIBDEXFILE_SUPPORT) |
| dex_files_ptr_.reset(new DexFiles(process_memory_)); |
| dex_files_ = dex_files_ptr_.get(); |
| SetDexFiles(dex_files_, arch); |
| #endif |
| |
| return true; |
| } |
| |
| } // namespace unwindstack |
