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/*
* 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 <assert.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/types.h>
#include <ucontext.h>
#include <string>
#include <android-base/stringprintf.h>
#include <backtrace/Backtrace.h>
#include <backtrace/BacktraceMap.h>
#include <demangle.h>
#include "BacktraceLog.h"
#include "UnwindCurrent.h"
#include "UnwindPtrace.h"
#include "UnwindStack.h"
#include "thread_utils.h"
using android::base::StringPrintf;
//-------------------------------------------------------------------------
// 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(uintptr_t pc, uintptr_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 "";
}
return demangle(GetFunctionNameRaw(pc, offset).c_str());
}
bool Backtrace::VerifyReadWordArgs(uintptr_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)) {
if (!frame->map.name.empty()) {
map_name = frame->map.name.c_str();
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 = StringPrintf("<anonymous:%" 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%" PRIxPTR, frame->map.offset) + ")";
}
if (!frame->func_name.empty()) {
line += " (" + frame->func_name;
if (frame->func_offset) {
line += StringPrintf("+%" PRIuPTR, frame->func_offset);
}
line += ')';
}
return line;
}
void Backtrace::FillInMap(uintptr_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 = gettid();
}
} else if (tid == BACKTRACE_CURRENT_THREAD) {
tid = pid;
}
if (pid == getpid()) {
return new UnwindCurrent(pid, tid, map);
} else {
return new UnwindPtrace(pid, tid, map);
}
}
Backtrace* Backtrace::CreateNew(pid_t pid, pid_t tid, BacktraceMap* map) {
if (pid == BACKTRACE_CURRENT_PROCESS) {
pid = getpid();
if (tid == BACKTRACE_CURRENT_THREAD) {
tid = gettid();
}
} else if (tid == BACKTRACE_CURRENT_THREAD) {
tid = pid;
}
if (map == nullptr) {
// This would cause the wrong type of map object to be created, so disallow.
#if defined(__ANDROID__)
__assert2(__FILE__, __LINE__, __PRETTY_FUNCTION__,
"Backtrace::CreateNew() must be called with a real map pointer.");
#else
BACK_LOGE("Backtrace::CreateNew() must be called with a real map pointer.");
abort();
#endif
}
if (pid == getpid()) {
return new UnwindStackCurrent(pid, tid, map);
} else {
return new UnwindStackPtrace(pid, tid, map);
}
}
std::string Backtrace::GetErrorString(BacktraceUnwindError error) {
switch (error) {
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";
}
}