android_system_core/libbacktrace/UnwindStack.cpp
Christopher Ferris 150db124f3 Add ability to read jit gdb data.
Changes:
- New JitDebug class to handle all of the jit gdb interface.
- Add unit tests for all, along with new offline test using debug data.
- Add new Memory type called MemoryOfflineParts that has multiple
  MemoryOffline objects to support the offline test.
- Update the tools to use the JitDebug object.
- Modify libbacktrace to use the JitDebug, but only looking in libart.so
  and libartd.so.
- Change the Format32Bits to Is32Bit since it's more accurate and I use
  it in a different context where original name didn't make sense.
- Add a new function to find global variables in an elf file
  (GetGlobalVariable).
- Add a new function to determine if a pc is valid for this elf (IsValidPc).

Bug: 68396769

Test: Ran new unit tests. Added new offline test that uses jit debug data.
Test: Ran art test that generates jit data and verified a crash unwinds
Test: through the jit data.
Change-Id: I6e7ee2f5bab2242028a06feece156dff21c0a974
2018-01-12 11:18:42 -08:00

132 lines
4.6 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 <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <ucontext.h>
#include <memory>
#include <set>
#include <string>
#if !defined(__ANDROID__)
#include <cutils/threads.h>
#endif
#include <backtrace/Backtrace.h>
#include <demangle.h>
#include <unwindstack/Elf.h>
#include <unwindstack/MapInfo.h>
#include <unwindstack/Maps.h>
#include <unwindstack/Memory.h>
#include <unwindstack/Regs.h>
#include <unwindstack/RegsGetLocal.h>
#include <unwindstack/Unwinder.h>
#include "BacktraceLog.h"
#include "UnwindStack.h"
#include "UnwindStackMap.h"
bool Backtrace::Unwind(unwindstack::Regs* regs, BacktraceMap* back_map,
std::vector<backtrace_frame_data_t>* frames, size_t num_ignore_frames,
std::vector<std::string>* skip_names) {
UnwindStackMap* stack_map = reinterpret_cast<UnwindStackMap*>(back_map);
auto process_memory = stack_map->process_memory();
unwindstack::Unwinder unwinder(MAX_BACKTRACE_FRAMES + num_ignore_frames, stack_map->stack_maps(),
regs, stack_map->process_memory());
unwinder.SetJitDebug(stack_map->GetJitDebug(), regs->Arch());
unwinder.Unwind(skip_names, &stack_map->GetSuffixesToIgnore());
if (num_ignore_frames >= unwinder.NumFrames()) {
frames->resize(0);
return true;
}
frames->resize(unwinder.NumFrames() - num_ignore_frames);
auto unwinder_frames = unwinder.frames();
size_t cur_frame = 0;
for (size_t i = num_ignore_frames; i < unwinder.NumFrames(); i++, cur_frame++) {
auto frame = &unwinder_frames[i];
backtrace_frame_data_t* back_frame = &frames->at(cur_frame);
back_frame->num = frame->num - num_ignore_frames;
back_frame->rel_pc = frame->rel_pc;
back_frame->pc = frame->pc;
back_frame->sp = frame->sp;
back_frame->func_name = demangle(frame->function_name.c_str());
back_frame->func_offset = frame->function_offset;
back_frame->map.name = frame->map_name;
back_frame->map.start = frame->map_start;
back_frame->map.end = frame->map_end;
back_frame->map.offset = frame->map_offset;
back_frame->map.load_bias = frame->map_load_bias;
back_frame->map.flags = frame->map_flags;
}
return true;
}
UnwindStackCurrent::UnwindStackCurrent(pid_t pid, pid_t tid, BacktraceMap* map)
: BacktraceCurrent(pid, tid, map) {}
std::string UnwindStackCurrent::GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) {
return GetMap()->GetFunctionName(pc, offset);
}
bool UnwindStackCurrent::UnwindFromContext(size_t num_ignore_frames, ucontext_t* ucontext) {
std::unique_ptr<unwindstack::Regs> regs;
if (ucontext == nullptr) {
regs.reset(unwindstack::Regs::CreateFromLocal());
// Fill in the registers from this function. Do it here to avoid
// one extra function call appearing in the unwind.
unwindstack::RegsGetLocal(regs.get());
} else {
regs.reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), ucontext));
}
error_.error_code = BACKTRACE_UNWIND_NO_ERROR;
std::vector<std::string> skip_names{"libunwindstack.so", "libbacktrace.so"};
return Backtrace::Unwind(regs.get(), GetMap(), &frames_, num_ignore_frames, &skip_names);
}
UnwindStackPtrace::UnwindStackPtrace(pid_t pid, pid_t tid, BacktraceMap* map)
: BacktracePtrace(pid, tid, map), memory_(pid) {}
std::string UnwindStackPtrace::GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) {
return GetMap()->GetFunctionName(pc, offset);
}
bool UnwindStackPtrace::Unwind(size_t num_ignore_frames, ucontext_t* context) {
std::unique_ptr<unwindstack::Regs> regs;
if (context == nullptr) {
regs.reset(unwindstack::Regs::RemoteGet(Tid()));
} else {
regs.reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), context));
}
error_.error_code = BACKTRACE_UNWIND_NO_ERROR;
return Backtrace::Unwind(regs.get(), GetMap(), &frames_, num_ignore_frames, nullptr);
}
size_t UnwindStackPtrace::Read(uintptr_t addr, uint8_t* buffer, size_t bytes) {
return memory_.Read(addr, buffer, bytes);
}