llvm-project/lldb/source/Target/ProcessTrace.cpp

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//===-- ProcessTrace.cpp --------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Target/ProcessTrace.h"
#include <memory>
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginManager.h"
[trace][intel-pt] Implement the basic decoding functionality Depends on D89408. This diff finally implements trace decoding! The current interface is $ trace load /path/to/trace/session/file.json $ thread trace dump instructions thread #1: tid = 3842849, total instructions = 22 [ 0] 0x40052d [ 1] 0x40052d ... [19] 0x400521 $ # simply enter, which is a repeat command [20] 0x40052d [21] 0x400529 ... This doesn't do any disassembly, which will be done in the next diff. Changes: - Added an IntelPTDecoder class, that is a wrapper for libipt, which is the actual library that performs the decoding. - Added TraceThreadDecoder class that decodes traces and memoizes the result to avoid repeating the decoding step. - Added a DecodedThread class, which represents the output from decoding and that for the time being only stores the list of reconstructed instructions. Later it'll contain the function call hierarchy, which will enable reconstructing backtraces. - Added basic APIs for accessing the trace in Trace.h: - GetInstructionCount, which counts the number of instructions traced for a given thread - IsTraceFailed, which returns an Error if decoding a thread failed - ForEachInstruction, which iterates on the instructions traced for a given thread, concealing the internal storage of threads, as plug-ins can decide to generate the instructions on the fly or to store them all in a vector, like I do. - DumpTraceInstructions was updated to print the instructions or show an error message if decoding was impossible. - Tests included Differential Revision: https://reviews.llvm.org/D89283
2020-10-15 01:26:10 +08:00
#include "lldb/Core/Section.h"
#include "lldb/Target/SectionLoadList.h"
#include "lldb/Target/Target.h"
using namespace lldb;
using namespace lldb_private;
llvm::StringRef ProcessTrace::GetPluginDescriptionStatic() {
return "Trace process plug-in.";
}
void ProcessTrace::Terminate() {
PluginManager::UnregisterPlugin(ProcessTrace::CreateInstance);
}
ProcessSP ProcessTrace::CreateInstance(TargetSP target_sp,
ListenerSP listener_sp,
const FileSpec *crash_file,
bool can_connect) {
if (can_connect)
return nullptr;
return std::make_shared<ProcessTrace>(target_sp, listener_sp);
}
bool ProcessTrace::CanDebug(TargetSP target_sp, bool plugin_specified_by_name) {
return plugin_specified_by_name;
}
ProcessTrace::ProcessTrace(TargetSP target_sp, ListenerSP listener_sp)
: PostMortemProcess(target_sp, listener_sp) {}
ProcessTrace::~ProcessTrace() {
Clear();
// We need to call finalize on the process before destroying ourselves to
// make sure all of the broadcaster cleanup goes as planned. If we destruct
// this class, then Process::~Process() might have problems trying to fully
// destroy the broadcaster.
Finalize();
}
void ProcessTrace::DidAttach(ArchSpec &process_arch) {
ListenerSP listener_sp(
Listener::MakeListener("lldb.process_trace.did_attach_listener"));
HijackProcessEvents(listener_sp);
SetCanJIT(false);
StartPrivateStateThread();
SetPrivateState(eStateStopped);
EventSP event_sp;
WaitForProcessToStop(llvm::None, &event_sp, true, listener_sp);
RestoreProcessEvents();
Process::DidAttach(process_arch);
}
2021-01-23 02:22:26 +08:00
bool ProcessTrace::DoUpdateThreadList(ThreadList &old_thread_list,
ThreadList &new_thread_list) {
return false;
}
void ProcessTrace::RefreshStateAfterStop() {}
Status ProcessTrace::DoDestroy() { return Status(); }
size_t ProcessTrace::ReadMemory(addr_t addr, void *buf, size_t size,
Status &error) {
// Don't allow the caching that lldb_private::Process::ReadMemory does since
// we have it all cached in the trace files.
return DoReadMemory(addr, buf, size, error);
}
void ProcessTrace::Clear() { m_thread_list.Clear(); }
void ProcessTrace::Initialize() {
static llvm::once_flag g_once_flag;
llvm::call_once(g_once_flag, []() {
PluginManager::RegisterPlugin(GetPluginNameStatic(),
GetPluginDescriptionStatic(), CreateInstance);
});
}
ArchSpec ProcessTrace::GetArchitecture() {
return GetTarget().GetArchitecture();
}
bool ProcessTrace::GetProcessInfo(ProcessInstanceInfo &info) {
info.Clear();
info.SetProcessID(GetID());
info.SetArchitecture(GetArchitecture());
ModuleSP module_sp = GetTarget().GetExecutableModule();
if (module_sp) {
const bool add_exe_file_as_first_arg = false;
info.SetExecutableFile(GetTarget().GetExecutableModule()->GetFileSpec(),
add_exe_file_as_first_arg);
}
return true;
}
size_t ProcessTrace::DoReadMemory(addr_t addr, void *buf, size_t size,
Status &error) {
[trace][intel-pt] Implement the basic decoding functionality Depends on D89408. This diff finally implements trace decoding! The current interface is $ trace load /path/to/trace/session/file.json $ thread trace dump instructions thread #1: tid = 3842849, total instructions = 22 [ 0] 0x40052d [ 1] 0x40052d ... [19] 0x400521 $ # simply enter, which is a repeat command [20] 0x40052d [21] 0x400529 ... This doesn't do any disassembly, which will be done in the next diff. Changes: - Added an IntelPTDecoder class, that is a wrapper for libipt, which is the actual library that performs the decoding. - Added TraceThreadDecoder class that decodes traces and memoizes the result to avoid repeating the decoding step. - Added a DecodedThread class, which represents the output from decoding and that for the time being only stores the list of reconstructed instructions. Later it'll contain the function call hierarchy, which will enable reconstructing backtraces. - Added basic APIs for accessing the trace in Trace.h: - GetInstructionCount, which counts the number of instructions traced for a given thread - IsTraceFailed, which returns an Error if decoding a thread failed - ForEachInstruction, which iterates on the instructions traced for a given thread, concealing the internal storage of threads, as plug-ins can decide to generate the instructions on the fly or to store them all in a vector, like I do. - DumpTraceInstructions was updated to print the instructions or show an error message if decoding was impossible. - Tests included Differential Revision: https://reviews.llvm.org/D89283
2020-10-15 01:26:10 +08:00
Address resolved_address;
GetTarget().GetSectionLoadList().ResolveLoadAddress(addr, resolved_address);
return GetTarget().ReadMemoryFromFileCache(resolved_address, buf, size,
error);
}