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| //===-- DynamicLoaderWindowsDYLD.cpp --------------------------------*- C++
//-*-===//
//
// 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 "DynamicLoaderWindowsDYLD.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Platform.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/ThreadPlanStepInstruction.h"
#include "lldb/Utility/Log.h"
#include "llvm/ADT/Triple.h"
using namespace lldb;
using namespace lldb_private;
DynamicLoaderWindowsDYLD::DynamicLoaderWindowsDYLD(Process *process)
: DynamicLoader(process) {}
DynamicLoaderWindowsDYLD::~DynamicLoaderWindowsDYLD() {}
void DynamicLoaderWindowsDYLD::Initialize() {
PluginManager::RegisterPlugin(GetPluginNameStatic(),
GetPluginDescriptionStatic(), CreateInstance);
}
void DynamicLoaderWindowsDYLD::Terminate() {}
ConstString DynamicLoaderWindowsDYLD::GetPluginNameStatic() {
static ConstString g_plugin_name("windows-dyld");
return g_plugin_name;
}
const char *DynamicLoaderWindowsDYLD::GetPluginDescriptionStatic() {
return "Dynamic loader plug-in that watches for shared library "
"loads/unloads in Windows processes.";
}
DynamicLoader *DynamicLoaderWindowsDYLD::CreateInstance(Process *process,
bool force) {
bool should_create = force;
if (!should_create) {
const llvm::Triple &triple_ref =
process->GetTarget().GetArchitecture().GetTriple();
if (triple_ref.getOS() == llvm::Triple::Win32)
should_create = true;
}
if (should_create)
return new DynamicLoaderWindowsDYLD(process);
return nullptr;
}
void DynamicLoaderWindowsDYLD::OnLoadModule(lldb::ModuleSP module_sp,
const ModuleSpec module_spec,
lldb::addr_t module_addr) {
// Resolve the module unless we already have one.
if (!module_sp) {
Status error;
module_sp = m_process->GetTarget().GetOrCreateModule(module_spec,
true /* notify */, &error);
if (error.Fail())
return;
}
m_loaded_modules[module_sp] = module_addr;
UpdateLoadedSectionsCommon(module_sp, module_addr, false);
ModuleList module_list;
module_list.Append(module_sp);
m_process->GetTarget().ModulesDidLoad(module_list);
}
void DynamicLoaderWindowsDYLD::OnUnloadModule(lldb::addr_t module_addr) {
Address resolved_addr;
if (!m_process->GetTarget().ResolveLoadAddress(module_addr, resolved_addr))
return;
ModuleSP module_sp = resolved_addr.GetModule();
if (module_sp) {
m_loaded_modules.erase(module_sp);
UnloadSectionsCommon(module_sp);
ModuleList module_list;
module_list.Append(module_sp);
m_process->GetTarget().ModulesDidUnload(module_list, false);
}
}
lldb::addr_t DynamicLoaderWindowsDYLD::GetLoadAddress(ModuleSP executable) {
// First, see if the load address is already cached.
auto it = m_loaded_modules.find(executable);
if (it != m_loaded_modules.end() && it->second != LLDB_INVALID_ADDRESS)
return it->second;
lldb::addr_t load_addr = LLDB_INVALID_ADDRESS;
// Second, try to get it through the process plugins. For a remote process,
// the remote platform will be responsible for providing it.
FileSpec file_spec(executable->GetPlatformFileSpec());
bool is_loaded = false;
Status status =
m_process->GetFileLoadAddress(file_spec, is_loaded, load_addr);
// Servers other than lldb server could respond with a bogus address.
if (status.Success() && is_loaded && load_addr != LLDB_INVALID_ADDRESS) {
m_loaded_modules[executable] = load_addr;
return load_addr;
}
return LLDB_INVALID_ADDRESS;
}
void DynamicLoaderWindowsDYLD::DidAttach() {
Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
LLDB_LOGF(log, "DynamicLoaderWindowsDYLD::%s()", __FUNCTION__);
ModuleSP executable = GetTargetExecutable();
if (!executable.get())
return;
// Try to fetch the load address of the file from the process, since there
// could be randomization of the load address.
lldb::addr_t load_addr = GetLoadAddress(executable);
if (load_addr == LLDB_INVALID_ADDRESS)
return;
// Request the process base address.
lldb::addr_t image_base = m_process->GetImageInfoAddress();
if (image_base == load_addr)
return;
// Rebase the process's modules if there is a mismatch.
UpdateLoadedSections(executable, LLDB_INVALID_ADDRESS, load_addr, false);
ModuleList module_list;
module_list.Append(executable);
m_process->GetTarget().ModulesDidLoad(module_list);
auto error = m_process->LoadModules();
LLDB_LOG_ERROR(log, std::move(error), "failed to load modules: {0}");
}
void DynamicLoaderWindowsDYLD::DidLaunch() {
Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
LLDB_LOGF(log, "DynamicLoaderWindowsDYLD::%s()", __FUNCTION__);
ModuleSP executable = GetTargetExecutable();
if (!executable.get())
return;
lldb::addr_t load_addr = GetLoadAddress(executable);
if (load_addr != LLDB_INVALID_ADDRESS) {
// Update the loaded sections so that the breakpoints can be resolved.
UpdateLoadedSections(executable, LLDB_INVALID_ADDRESS, load_addr, false);
ModuleList module_list;
module_list.Append(executable);
m_process->GetTarget().ModulesDidLoad(module_list);
auto error = m_process->LoadModules();
LLDB_LOG_ERROR(log, std::move(error), "failed to load modules: {0}");
}
}
Status DynamicLoaderWindowsDYLD::CanLoadImage() { return Status(); }
ConstString DynamicLoaderWindowsDYLD::GetPluginName() {
return GetPluginNameStatic();
}
uint32_t DynamicLoaderWindowsDYLD::GetPluginVersion() { return 1; }
ThreadPlanSP
DynamicLoaderWindowsDYLD::GetStepThroughTrampolinePlan(Thread &thread,
bool stop) {
auto arch = m_process->GetTarget().GetArchitecture();
if (arch.GetMachine() != llvm::Triple::x86) {
return ThreadPlanSP();
}
uint64_t pc = thread.GetRegisterContext()->GetPC();
// Max size of an instruction in x86 is 15 bytes.
AddressRange range(pc, 2 * 15);
ExecutionContext exe_ctx(m_process->GetTarget());
DisassemblerSP disassembler_sp = Disassembler::DisassembleRange(
arch, nullptr, nullptr, exe_ctx, range, true);
if (!disassembler_sp) {
return ThreadPlanSP();
}
InstructionList *insn_list = &disassembler_sp->GetInstructionList();
if (insn_list == nullptr) {
return ThreadPlanSP();
}
// First instruction in a x86 Windows trampoline is going to be an indirect
// jump through the IAT and the next one will be a nop (usually there for
// alignment purposes). e.g.:
// 0x70ff4cfc <+956>: jmpl *0x7100c2a8
// 0x70ff4d02 <+962>: nop
auto first_insn = insn_list->GetInstructionAtIndex(0);
auto second_insn = insn_list->GetInstructionAtIndex(1);
if (first_insn == nullptr || second_insn == nullptr ||
strcmp(first_insn->GetMnemonic(&exe_ctx), "jmpl") != 0 ||
strcmp(second_insn->GetMnemonic(&exe_ctx), "nop") != 0) {
return ThreadPlanSP();
}
assert(first_insn->DoesBranch() && !second_insn->DoesBranch());
return ThreadPlanSP(new ThreadPlanStepInstruction(
thread, false, false, eVoteNoOpinion, eVoteNoOpinion));
}
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