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Diffstat (limited to 'libbacktrace/Backtrace.cpp')
| -rw-r--r-- | libbacktrace/Backtrace.cpp | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/libbacktrace/Backtrace.cpp b/libbacktrace/Backtrace.cpp new file mode 100644 index 000000000..3e050ab68 --- /dev/null +++ b/libbacktrace/Backtrace.cpp @@ -0,0 +1,183 @@ +/* + * Copyright (C) 2013 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. + */ + +#include <inttypes.h> +#include <stdint.h> +#include <stdlib.h> +#include <sys/types.h> +#include <ucontext.h> + +#include <string> + +#include <android-base/stringprintf.h> +#include <android-base/threads.h> + +#include <backtrace/Backtrace.h> +#include <backtrace/BacktraceMap.h> + +#include "BacktraceLog.h" +#include "UnwindStack.h" + +using android::base::StringPrintf; + +extern "C" char* __cxa_demangle(const char*, char*, size_t*, int*); + +//------------------------------------------------------------------------- +// Backtrace functions. +//------------------------------------------------------------------------- +Backtrace::Backtrace(pid_t pid, pid_t tid, BacktraceMap* map) + : pid_(pid), tid_(tid), map_(map), map_shared_(true) { + if (map_ == nullptr) { + map_ = BacktraceMap::Create(pid); + map_shared_ = false; + } +} + +Backtrace::~Backtrace() { + if (map_ && !map_shared_) { + delete map_; + map_ = nullptr; + } +} + +std::string Backtrace::GetFunctionName(uint64_t pc, uint64_t* offset, const backtrace_map_t* map) { + backtrace_map_t map_value; + if (map == nullptr) { + FillInMap(pc, &map_value); + map = &map_value; + } + // If no map is found, or this map is backed by a device, then return nothing. + if (map->start == 0 || (map->flags & PROT_DEVICE_MAP)) { + return ""; + } + std::string name(GetFunctionNameRaw(pc, offset)); + char* demangled_name = __cxa_demangle(name.c_str(), nullptr, nullptr, nullptr); + if (demangled_name != nullptr) { + name = demangled_name; + free(demangled_name); + return name; + } + return name; +} + +bool Backtrace::VerifyReadWordArgs(uint64_t ptr, word_t* out_value) { + if (ptr & (sizeof(word_t)-1)) { + BACK_LOGW("invalid pointer %p", reinterpret_cast<void*>(ptr)); + *out_value = static_cast<word_t>(-1); + return false; + } + return true; +} + +std::string Backtrace::FormatFrameData(size_t frame_num) { + if (frame_num >= frames_.size()) { + return ""; + } + return FormatFrameData(&frames_[frame_num]); +} + +std::string Backtrace::FormatFrameData(const backtrace_frame_data_t* frame) { + std::string map_name; + if (BacktraceMap::IsValid(frame->map)) { + map_name = frame->map.Name(); + if (!frame->map.name.empty()) { + if (map_name[0] == '[' && map_name[map_name.size() - 1] == ']') { + map_name.resize(map_name.size() - 1); + map_name += StringPrintf(":%" PRIPTR "]", frame->map.start); + } + } + } else { + map_name = "<unknown>"; + } + + std::string line(StringPrintf("#%02zu pc %" PRIPTR " ", frame->num, frame->rel_pc)); + line += map_name; + // Special handling for non-zero offset maps, we need to print that + // information. + if (frame->map.offset != 0) { + line += " (offset " + StringPrintf("0x%" PRIx64, frame->map.offset) + ")"; + } + if (!frame->func_name.empty()) { + line += " (" + frame->func_name; + if (frame->func_offset) { + line += StringPrintf("+%" PRIu64, frame->func_offset); + } + line += ')'; + } + + return line; +} + +void Backtrace::FillInMap(uint64_t pc, backtrace_map_t* map) { + if (map_ != nullptr) { + map_->FillIn(pc, map); + } +} + +Backtrace* Backtrace::Create(pid_t pid, pid_t tid, BacktraceMap* map) { + if (pid == BACKTRACE_CURRENT_PROCESS) { + pid = getpid(); + if (tid == BACKTRACE_CURRENT_THREAD) { + tid = android::base::GetThreadId(); + } + } else if (tid == BACKTRACE_CURRENT_THREAD) { + tid = pid; + } + + if (pid == getpid()) { + return new UnwindStackCurrent(pid, tid, map); + } else { + return new UnwindStackPtrace(pid, tid, map); + } +} + +std::string Backtrace::GetErrorString(BacktraceUnwindError error) { + switch (error.error_code) { + case BACKTRACE_UNWIND_NO_ERROR: + return "No error"; + case BACKTRACE_UNWIND_ERROR_SETUP_FAILED: + return "Setup failed"; + case BACKTRACE_UNWIND_ERROR_MAP_MISSING: + return "No map found"; + case BACKTRACE_UNWIND_ERROR_INTERNAL: + return "Internal libbacktrace error, please submit a bugreport"; + case BACKTRACE_UNWIND_ERROR_THREAD_DOESNT_EXIST: + return "Thread doesn't exist"; + case BACKTRACE_UNWIND_ERROR_THREAD_TIMEOUT: + return "Thread has not responded to signal in time"; + case BACKTRACE_UNWIND_ERROR_UNSUPPORTED_OPERATION: + return "Attempt to use an unsupported feature"; + case BACKTRACE_UNWIND_ERROR_NO_CONTEXT: + return "Attempt to do an offline unwind without a context"; + case BACKTRACE_UNWIND_ERROR_EXCEED_MAX_FRAMES_LIMIT: + return "Exceed MAX_BACKTRACE_FRAMES limit"; + case BACKTRACE_UNWIND_ERROR_ACCESS_MEM_FAILED: + return android::base::StringPrintf("Failed to read memory at addr 0x%" PRIx64, + error.error_info.addr); + case BACKTRACE_UNWIND_ERROR_ACCESS_REG_FAILED: + return android::base::StringPrintf("Failed to read register %" PRIu64, error.error_info.regno); + case BACKTRACE_UNWIND_ERROR_FIND_PROC_INFO_FAILED: + return "Failed to find a function in debug sections"; + case BACKTRACE_UNWIND_ERROR_EXECUTE_DWARF_INSTRUCTION_FAILED: + return "Failed to execute dwarf instructions in debug sections"; + case BACKTRACE_UNWIND_ERROR_UNWIND_INFO: + return "Failed to unwind due to invalid unwind information"; + case BACKTRACE_UNWIND_ERROR_REPEATED_FRAME: + return "Failed to unwind due to same sp/pc repeating"; + case BACKTRACE_UNWIND_ERROR_INVALID_ELF: + return "Failed to unwind due to invalid elf"; + } +} |