| /* |
| * 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 <errno.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/ptrace.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include <string> |
| |
| #include <backtrace/Backtrace.h> |
| #include <backtrace/BacktraceMap.h> |
| |
| #include "BacktraceImpl.h" |
| #include "BacktraceLog.h" |
| #include "thread_utils.h" |
| |
| //------------------------------------------------------------------------- |
| // Backtrace functions. |
| //------------------------------------------------------------------------- |
| Backtrace::Backtrace(BacktraceImpl* impl, pid_t pid, BacktraceMap* map) |
| : pid_(pid), tid_(-1), map_(map), map_shared_(true), impl_(impl) { |
| impl_->SetParent(this); |
| |
| if (map_ == NULL) { |
| map_ = BacktraceMap::Create(pid); |
| map_shared_ = false; |
| } |
| } |
| |
| Backtrace::~Backtrace() { |
| if (impl_) { |
| delete impl_; |
| impl_ = NULL; |
| } |
| |
| if (map_ && !map_shared_) { |
| delete map_; |
| map_ = NULL; |
| } |
| } |
| |
| bool Backtrace::Unwind(size_t num_ignore_frames) { |
| return impl_->Unwind(num_ignore_frames); |
| } |
| |
| extern "C" char* __cxa_demangle(const char* mangled, char* buf, size_t* len, |
| int* status); |
| |
| std::string Backtrace::GetFunctionName(uintptr_t pc, uintptr_t* offset) { |
| std::string func_name = impl_->GetFunctionNameRaw(pc, offset); |
| if (!func_name.empty()) { |
| #if defined(__APPLE__) |
| // Mac OS' __cxa_demangle demangles "f" as "float"; last tested on 10.7. |
| if (func_name[0] != '_') { |
| return func_name; |
| } |
| #endif |
| char* name = __cxa_demangle(func_name.c_str(), 0, 0, 0); |
| if (name) { |
| func_name = name; |
| free(name); |
| } |
| } |
| return func_name; |
| } |
| |
| bool Backtrace::VerifyReadWordArgs(uintptr_t ptr, word_t* out_value) { |
| if (ptr & (sizeof(word_t)-1)) { |
| BACK_LOGW("invalid pointer %p", (void*)ptr); |
| *out_value = (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) { |
| const char* map_name; |
| if (frame->map && !frame->map->name.empty()) { |
| map_name = frame->map->name.c_str(); |
| } else { |
| map_name = "<unknown>"; |
| } |
| |
| uintptr_t relative_pc; |
| if (frame->map) { |
| relative_pc = frame->pc - frame->map->start; |
| } else { |
| relative_pc = frame->pc; |
| } |
| |
| char buf[512]; |
| if (!frame->func_name.empty() && frame->func_offset) { |
| snprintf(buf, sizeof(buf), "#%02zu pc %0*" PRIxPTR " %s (%s+%" PRIuPTR ")", |
| frame->num, (int)sizeof(uintptr_t)*2, relative_pc, map_name, |
| frame->func_name.c_str(), frame->func_offset); |
| } else if (!frame->func_name.empty()) { |
| snprintf(buf, sizeof(buf), "#%02zu pc %0*" PRIxPTR " %s (%s)", frame->num, |
| (int)sizeof(uintptr_t)*2, relative_pc, map_name, frame->func_name.c_str()); |
| } else { |
| snprintf(buf, sizeof(buf), "#%02zu pc %0*" PRIxPTR " %s", frame->num, |
| (int)sizeof(uintptr_t)*2, relative_pc, map_name); |
| } |
| |
| return buf; |
| } |
| |
| const backtrace_map_t* Backtrace::FindMap(uintptr_t pc) { |
| return map_->Find(pc); |
| } |
| |
| //------------------------------------------------------------------------- |
| // BacktraceCurrent functions. |
| //------------------------------------------------------------------------- |
| BacktraceCurrent::BacktraceCurrent( |
| BacktraceImpl* impl, BacktraceMap* map) : Backtrace(impl, getpid(), map) { |
| } |
| |
| BacktraceCurrent::~BacktraceCurrent() { |
| } |
| |
| bool BacktraceCurrent::ReadWord(uintptr_t ptr, word_t* out_value) { |
| if (!VerifyReadWordArgs(ptr, out_value)) { |
| return false; |
| } |
| |
| const backtrace_map_t* map = FindMap(ptr); |
| if (map && map->flags & PROT_READ) { |
| *out_value = *reinterpret_cast<word_t*>(ptr); |
| return true; |
| } else { |
| BACK_LOGW("pointer %p not in a readable map", reinterpret_cast<void*>(ptr)); |
| *out_value = static_cast<word_t>(-1); |
| return false; |
| } |
| } |
| |
| //------------------------------------------------------------------------- |
| // BacktracePtrace functions. |
| //------------------------------------------------------------------------- |
| BacktracePtrace::BacktracePtrace( |
| BacktraceImpl* impl, pid_t pid, pid_t tid, BacktraceMap* map) |
| : Backtrace(impl, pid, map) { |
| tid_ = tid; |
| } |
| |
| BacktracePtrace::~BacktracePtrace() { |
| } |
| |
| bool BacktracePtrace::ReadWord(uintptr_t ptr, word_t* out_value) { |
| if (!VerifyReadWordArgs(ptr, out_value)) { |
| return false; |
| } |
| |
| #if defined(__APPLE__) |
| BACK_LOGW("MacOS does not support reading from another pid."); |
| return false; |
| #else |
| // ptrace() returns -1 and sets errno when the operation fails. |
| // To disambiguate -1 from a valid result, we clear errno beforehand. |
| errno = 0; |
| *out_value = ptrace(PTRACE_PEEKTEXT, Tid(), reinterpret_cast<void*>(ptr), NULL); |
| if (*out_value == static_cast<word_t>(-1) && errno) { |
| BACK_LOGW("invalid pointer %p reading from tid %d, ptrace() strerror(errno)=%s", |
| reinterpret_cast<void*>(ptr), Tid(), strerror(errno)); |
| return false; |
| } |
| return true; |
| #endif |
| } |
| |
| Backtrace* Backtrace::Create(pid_t pid, pid_t tid, BacktraceMap* map) { |
| if (pid == BACKTRACE_CURRENT_PROCESS || pid == getpid()) { |
| if (tid == BACKTRACE_CURRENT_THREAD || tid == gettid()) { |
| return CreateCurrentObj(map); |
| } else { |
| return CreateThreadObj(tid, map); |
| } |
| } else if (tid == BACKTRACE_CURRENT_THREAD) { |
| return CreatePtraceObj(pid, pid, map); |
| } else { |
| return CreatePtraceObj(pid, tid, map); |
| } |
| } |