llvm-project/lldb/source/Plugins/ScriptInterpreter/Python/ScriptedProcessPythonInterface.cpp
Med Ismail Bennani a758c9f720 [lldb/Plugins] Add memory region support in ScriptedProcess
This patch adds support for memory regions in Scripted Processes.
This is necessary to read the stack memory region in order to
reconstruct each stackframe of the program.

In order to do so, this patch makes some changes to the SBAPI, namely:
- Add a new constructor for `SBMemoryRegionInfo` that takes arguments
  such as the memory region name, address range, permissions ...
  This is used when reading memory at some address to compute the offset
  in the binary blob provided by the user.
- Add a `GetMemoryRegionContainingAddress` method to `SBMemoryRegionInfoList`
  to simplify the access to a specific memory region.

With these changes, lldb is now able to unwind the stack and reconstruct
each frame. On top of that, reloading the target module at offset 0 allows
lldb to symbolicate the `ScriptedProcess` using debug info, similarly to an
ordinary Process.

To test this, I wrote a simple program with multiple function calls, ran it in
lldb, stopped at a leaf function and read the registers values and copied
the stack memory into a binary file. These are then used in the python script.

Differential Revision: https://reviews.llvm.org/D108953

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2021-10-08 14:54:07 +02:00

170 lines
4.9 KiB
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//===-- ScriptedProcessPythonInterface.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/Host/Config.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/Logging.h"
#include "lldb/lldb-enumerations.h"
#if LLDB_ENABLE_PYTHON
// LLDB Python header must be included first
#include "lldb-python.h"
#include "SWIGPythonBridge.h"
#include "ScriptInterpreterPythonImpl.h"
#include "ScriptedProcessPythonInterface.h"
#include "ScriptedThreadPythonInterface.h"
using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::python;
using Locker = ScriptInterpreterPythonImpl::Locker;
ScriptedProcessPythonInterface::ScriptedProcessPythonInterface(
ScriptInterpreterPythonImpl &interpreter)
: ScriptedProcessInterface(), ScriptedPythonInterface(interpreter) {}
StructuredData::GenericSP ScriptedProcessPythonInterface::CreatePluginObject(
llvm::StringRef class_name, ExecutionContext &exe_ctx,
StructuredData::DictionarySP args_sp) {
if (class_name.empty())
return {};
TargetSP target_sp = exe_ctx.GetTargetSP();
StructuredDataImpl *args_impl = nullptr;
if (args_sp) {
args_impl = new StructuredDataImpl();
args_impl->SetObjectSP(args_sp);
}
std::string error_string;
Locker py_lock(&m_interpreter, Locker::AcquireLock | Locker::NoSTDIN,
Locker::FreeLock);
void *ret_val = LLDBSwigPythonCreateScriptedProcess(
class_name.str().c_str(), m_interpreter.GetDictionaryName(), target_sp,
args_impl, error_string);
if (!ret_val)
return {};
m_object_instance_sp =
StructuredData::GenericSP(new StructuredPythonObject(ret_val));
return m_object_instance_sp;
}
Status ScriptedProcessPythonInterface::Launch() {
return GetStatusFromMethod("launch");
}
Status ScriptedProcessPythonInterface::Resume() {
return GetStatusFromMethod("resume");
}
bool ScriptedProcessPythonInterface::ShouldStop() {
Status error;
StructuredData::ObjectSP obj = Dispatch("is_alive", error);
if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
return {};
return obj->GetBooleanValue();
}
Status ScriptedProcessPythonInterface::Stop() {
return GetStatusFromMethod("stop");
}
llvm::Optional<MemoryRegionInfo>
ScriptedProcessPythonInterface::GetMemoryRegionContainingAddress(
lldb::addr_t address, Status &error) {
auto mem_region = Dispatch<llvm::Optional<MemoryRegionInfo>>(
"get_memory_region_containing_address", error, address);
if (error.Fail()) {
return ErrorWithMessage<MemoryRegionInfo>(__PRETTY_FUNCTION__,
error.AsCString(), error);
}
return mem_region;
}
StructuredData::DictionarySP
ScriptedProcessPythonInterface::GetThreadWithID(lldb::tid_t tid) {
Status error;
StructuredData::ObjectSP obj = Dispatch("get_thread_with_id", error, tid);
if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
return {};
StructuredData::DictionarySP dict{obj->GetAsDictionary()};
return dict;
}
StructuredData::DictionarySP
ScriptedProcessPythonInterface::GetRegistersForThread(lldb::tid_t tid) {
// TODO: Implement
return {};
}
lldb::DataExtractorSP ScriptedProcessPythonInterface::ReadMemoryAtAddress(
lldb::addr_t address, size_t size, Status &error) {
return Dispatch<lldb::DataExtractorSP>("read_memory_at_address", error,
address, size);
}
StructuredData::DictionarySP ScriptedProcessPythonInterface::GetLoadedImages() {
// TODO: Implement
return {};
}
lldb::pid_t ScriptedProcessPythonInterface::GetProcessID() {
Status error;
StructuredData::ObjectSP obj = Dispatch("get_process_id", error);
if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
return LLDB_INVALID_PROCESS_ID;
return obj->GetIntegerValue(LLDB_INVALID_PROCESS_ID);
}
bool ScriptedProcessPythonInterface::IsAlive() {
Status error;
StructuredData::ObjectSP obj = Dispatch("is_alive", error);
if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
return {};
return obj->GetBooleanValue();
}
llvm::Optional<std::string>
ScriptedProcessPythonInterface::GetScriptedThreadPluginName() {
Status error;
StructuredData::ObjectSP obj = Dispatch("get_scripted_thread_plugin", error);
if (!CheckStructuredDataObject(__PRETTY_FUNCTION__, obj, error))
return {};
return obj->GetStringValue().str();
}
lldb::ScriptedThreadInterfaceSP
ScriptedProcessPythonInterface::GetScriptedThreadInterface() {
if (!m_scripted_thread_interface_sp)
m_scripted_thread_interface_sp =
std::make_shared<ScriptedThreadPythonInterface>(m_interpreter);
return m_scripted_thread_interface_sp;
}
#endif