Files
clang-p2996/lldb/source/Plugins/Process/NetBSD/NativeThreadNetBSD.cpp
Michał Górny 8d9400b65b [lldb] [Process/NetBSD] Improve threading support
Implement major improvements to multithreaded program support.  Notably,
support tracking new and exited threads, associate signals and events
with correct threads and support controlling individual threads when
resuming.

Firstly, use PT_SET_EVENT_MASK to enable reporting of created and exited
threads via SIGTRAP.  Handle TRAP_LWP events to keep track
of the currently running threads.

Secondly, update the signal (both generic and SIGTRAP) handling code
to account for per-thread signals correctly.  Signals delivered
to the whole process are reported on all threads, while per-thread
signals and events are reported only to the specific thread.
The remaining threads are marked as 'stopped with no reason'.  Note that
NetBSD always stops all threads on debugger events.

Thirdly, implement the ability to set every thread as running, stopped
or single-stepping separately while continuing the process.  This also
provides the ability to send a signal to the whole process or to one
of its thread while resuming.

Differential Revision: https://reviews.llvm.org/D70022
2019-11-25 20:11:58 +01:00

287 lines
8.4 KiB
C++

//===-- NativeThreadNetBSD.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 "NativeThreadNetBSD.h"
#include "NativeRegisterContextNetBSD.h"
#include "NativeProcessNetBSD.h"
#include "Plugins/Process/POSIX/CrashReason.h"
#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
#include "lldb/Utility/LLDBAssert.h"
#include "lldb/Utility/RegisterValue.h"
#include "lldb/Utility/State.h"
#include "llvm/Support/Errno.h"
// clang-format off
#include <sys/types.h>
#include <sys/ptrace.h>
// clang-format on
#include <sstream>
// clang-format off
#include <sys/types.h>
#include <sys/sysctl.h>
// clang-format on
using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::process_netbsd;
NativeThreadNetBSD::NativeThreadNetBSD(NativeProcessNetBSD &process,
lldb::tid_t tid)
: NativeThreadProtocol(process, tid), m_state(StateType::eStateInvalid),
m_stop_info(), m_reg_context_up(
NativeRegisterContextNetBSD::CreateHostNativeRegisterContextNetBSD(process.GetArchitecture(), *this)
), m_stop_description() {}
Status NativeThreadNetBSD::Resume() {
Status ret = NativeProcessNetBSD::PtraceWrapper(PT_RESUME, m_process.GetID(),
nullptr, GetID());
if (!ret.Success())
return ret;
ret = NativeProcessNetBSD::PtraceWrapper(PT_CLEARSTEP, m_process.GetID(),
nullptr, GetID());
if (ret.Success())
SetRunning();
return ret;
}
Status NativeThreadNetBSD::SingleStep() {
Status ret = NativeProcessNetBSD::PtraceWrapper(PT_RESUME, m_process.GetID(),
nullptr, GetID());
if (!ret.Success())
return ret;
ret = NativeProcessNetBSD::PtraceWrapper(PT_SETSTEP, m_process.GetID(),
nullptr, GetID());
if (ret.Success())
SetStepping();
return ret;
}
Status NativeThreadNetBSD::Suspend() {
Status ret = NativeProcessNetBSD::PtraceWrapper(PT_SUSPEND, m_process.GetID(),
nullptr, GetID());
if (ret.Success())
SetStopped();
return ret;
}
void NativeThreadNetBSD::SetStoppedBySignal(uint32_t signo,
const siginfo_t *info) {
Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
LLDB_LOG(log, "tid = {0} in called with signal {1}", GetID(), signo);
SetStopped();
m_stop_info.reason = StopReason::eStopReasonSignal;
m_stop_info.details.signal.signo = signo;
m_stop_description.clear();
if (info) {
switch (signo) {
case SIGSEGV:
case SIGBUS:
case SIGFPE:
case SIGILL:
const auto reason = GetCrashReason(*info);
m_stop_description = GetCrashReasonString(reason, *info);
break;
}
}
}
void NativeThreadNetBSD::SetStoppedByBreakpoint() {
SetStopped();
m_stop_info.reason = StopReason::eStopReasonBreakpoint;
m_stop_info.details.signal.signo = SIGTRAP;
}
void NativeThreadNetBSD::SetStoppedByTrace() {
SetStopped();
m_stop_info.reason = StopReason::eStopReasonTrace;
m_stop_info.details.signal.signo = SIGTRAP;
}
void NativeThreadNetBSD::SetStoppedByExec() {
SetStopped();
m_stop_info.reason = StopReason::eStopReasonExec;
m_stop_info.details.signal.signo = SIGTRAP;
}
void NativeThreadNetBSD::SetStoppedByWatchpoint(uint32_t wp_index) {
SetStopped();
lldbassert(wp_index != LLDB_INVALID_INDEX32 && "wp_index cannot be invalid");
std::ostringstream ostr;
ostr << GetRegisterContext().GetWatchpointAddress(wp_index) << " ";
ostr << wp_index;
ostr << " " << GetRegisterContext().GetWatchpointHitAddress(wp_index);
m_stop_description = ostr.str();
m_stop_info.reason = StopReason::eStopReasonWatchpoint;
m_stop_info.details.signal.signo = SIGTRAP;
}
void NativeThreadNetBSD::SetStoppedWithNoReason() {
SetStopped();
m_stop_info.reason = StopReason::eStopReasonNone;
m_stop_info.details.signal.signo = 0;
}
void NativeThreadNetBSD::SetStopped() {
const StateType new_state = StateType::eStateStopped;
m_state = new_state;
m_stop_description.clear();
}
void NativeThreadNetBSD::SetRunning() {
m_state = StateType::eStateRunning;
m_stop_info.reason = StopReason::eStopReasonNone;
}
void NativeThreadNetBSD::SetStepping() {
m_state = StateType::eStateStepping;
m_stop_info.reason = StopReason::eStopReasonNone;
}
std::string NativeThreadNetBSD::GetName() {
Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
std::vector<struct kinfo_lwp> infos;
int mib[5] = {CTL_KERN, KERN_LWP, static_cast<int>(m_process.GetID()),
sizeof(struct kinfo_lwp), 0};
size_t size;
if (::sysctl(mib, 5, nullptr, &size, nullptr, 0) == -1 || size == 0) {
LLDB_LOG(log, "sysctl() for LWP info size failed: {0}",
llvm::sys::StrError());
return "";
}
mib[4] = size / sizeof(size_t);
infos.resize(size / sizeof(struct kinfo_lwp));
if (sysctl(mib, 5, infos.data(), &size, NULL, 0) == -1 || size == 0) {
LLDB_LOG(log, "sysctl() for LWP info failed: {0}", llvm::sys::StrError());
return "";
}
size_t nlwps = size / sizeof(struct kinfo_lwp);
for (size_t i = 0; i < nlwps; i++) {
if (static_cast<lldb::tid_t>(infos[i].l_lid) == m_tid) {
return infos[i].l_name;
}
}
LLDB_LOG(log, "unable to find lwp {0} in LWP infos", m_tid);
return "";
}
lldb::StateType NativeThreadNetBSD::GetState() { return m_state; }
bool NativeThreadNetBSD::GetStopReason(ThreadStopInfo &stop_info,
std::string &description) {
Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
description.clear();
switch (m_state) {
case eStateStopped:
case eStateCrashed:
case eStateExited:
case eStateSuspended:
case eStateUnloaded:
stop_info = m_stop_info;
description = m_stop_description;
return true;
case eStateInvalid:
case eStateConnected:
case eStateAttaching:
case eStateLaunching:
case eStateRunning:
case eStateStepping:
case eStateDetached:
LLDB_LOG(log, "tid = {0} in state {1} cannot answer stop reason", GetID(),
StateAsCString(m_state));
return false;
}
llvm_unreachable("unhandled StateType!");
}
NativeRegisterContext& NativeThreadNetBSD::GetRegisterContext() {
assert(m_reg_context_up);
return *m_reg_context_up;
}
Status NativeThreadNetBSD::SetWatchpoint(lldb::addr_t addr, size_t size,
uint32_t watch_flags, bool hardware) {
if (!hardware)
return Status("not implemented");
if (m_state == eStateLaunching)
return Status();
Status error = RemoveWatchpoint(addr);
if (error.Fail())
return error;
uint32_t wp_index = GetRegisterContext().SetHardwareWatchpoint(addr, size, watch_flags);
if (wp_index == LLDB_INVALID_INDEX32)
return Status("Setting hardware watchpoint failed.");
m_watchpoint_index_map.insert({addr, wp_index});
return Status();
}
Status NativeThreadNetBSD::RemoveWatchpoint(lldb::addr_t addr) {
auto wp = m_watchpoint_index_map.find(addr);
if (wp == m_watchpoint_index_map.end())
return Status();
uint32_t wp_index = wp->second;
m_watchpoint_index_map.erase(wp);
if (GetRegisterContext().ClearHardwareWatchpoint(wp_index))
return Status();
return Status("Clearing hardware watchpoint failed.");
}
Status NativeThreadNetBSD::SetHardwareBreakpoint(lldb::addr_t addr,
size_t size) {
if (m_state == eStateLaunching)
return Status();
Status error = RemoveHardwareBreakpoint(addr);
if (error.Fail())
return error;
uint32_t bp_index = GetRegisterContext().SetHardwareBreakpoint(addr, size);
if (bp_index == LLDB_INVALID_INDEX32)
return Status("Setting hardware breakpoint failed.");
m_hw_break_index_map.insert({addr, bp_index});
return Status();
}
Status NativeThreadNetBSD::RemoveHardwareBreakpoint(lldb::addr_t addr) {
auto bp = m_hw_break_index_map.find(addr);
if (bp == m_hw_break_index_map.end())
return Status();
uint32_t bp_index = bp->second;
if (GetRegisterContext().ClearHardwareBreakpoint(bp_index)) {
m_hw_break_index_map.erase(bp);
return Status();
}
return Status("Clearing hardware breakpoint failed.");
}