1 //===-- NativeThreadFreeBSD.cpp -------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "NativeThreadFreeBSD.h"
10 #include "NativeRegisterContextFreeBSD.h"
11 
12 #include "NativeProcessFreeBSD.h"
13 
14 #include "Plugins/Process/POSIX/CrashReason.h"
15 #include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
16 #include "lldb/Utility/LLDBAssert.h"
17 #include "lldb/Utility/RegisterValue.h"
18 #include "lldb/Utility/State.h"
19 #include "llvm/Support/Errno.h"
20 
21 // clang-format off
22 #include <sys/types.h>
23 #include <sys/ptrace.h>
24 #include <sys/sysctl.h>
25 #include <sys/user.h>
26 // clang-format on
27 
28 #include <sstream>
29 #include <vector>
30 
31 using namespace lldb;
32 using namespace lldb_private;
33 using namespace lldb_private::process_freebsd;
34 
NativeThreadFreeBSD(NativeProcessFreeBSD & process,lldb::tid_t tid)35 NativeThreadFreeBSD::NativeThreadFreeBSD(NativeProcessFreeBSD &process,
36                                          lldb::tid_t tid)
37     : NativeThreadProtocol(process, tid), m_state(StateType::eStateInvalid),
38       m_stop_info(),
39       m_reg_context_up(
40           NativeRegisterContextFreeBSD::CreateHostNativeRegisterContextFreeBSD(
41               process.GetArchitecture(), *this)),
42       m_stop_description() {}
43 
Resume()44 Status NativeThreadFreeBSD::Resume() {
45   Status ret = NativeProcessFreeBSD::PtraceWrapper(PT_RESUME, GetID());
46   if (!ret.Success())
47     return ret;
48   ret = NativeProcessFreeBSD::PtraceWrapper(PT_CLEARSTEP, GetID());
49   // we can get EINVAL if the architecture in question does not support
50   // hardware single-stepping -- that's fine, we have nothing to clear
51   // then
52   if (ret.GetError() == EINVAL)
53     ret.Clear();
54   if (ret.Success())
55     SetRunning();
56   return ret;
57 }
58 
SingleStep()59 Status NativeThreadFreeBSD::SingleStep() {
60   Status ret = NativeProcessFreeBSD::PtraceWrapper(PT_RESUME, GetID());
61   if (!ret.Success())
62     return ret;
63   ret = NativeProcessFreeBSD::PtraceWrapper(PT_SETSTEP, GetID());
64   if (ret.Success())
65     SetStepping();
66   return ret;
67 }
68 
Suspend()69 Status NativeThreadFreeBSD::Suspend() {
70   Status ret = NativeProcessFreeBSD::PtraceWrapper(PT_SUSPEND, GetID());
71   if (ret.Success())
72     SetStopped();
73   return ret;
74 }
75 
SetStoppedBySignal(uint32_t signo,const siginfo_t * info)76 void NativeThreadFreeBSD::SetStoppedBySignal(uint32_t signo,
77                                              const siginfo_t *info) {
78   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
79   LLDB_LOG(log, "tid = {0} in called with signal {1}", GetID(), signo);
80 
81   SetStopped();
82 
83   m_stop_info.reason = StopReason::eStopReasonSignal;
84   m_stop_info.details.signal.signo = signo;
85 
86   m_stop_description.clear();
87   if (info) {
88     switch (signo) {
89     case SIGSEGV:
90     case SIGBUS:
91     case SIGFPE:
92     case SIGILL:
93       const auto reason = GetCrashReason(*info);
94       m_stop_description = GetCrashReasonString(reason, *info);
95       break;
96     }
97   }
98 }
99 
SetStoppedByBreakpoint()100 void NativeThreadFreeBSD::SetStoppedByBreakpoint() {
101   SetStopped();
102   m_stop_info.reason = StopReason::eStopReasonBreakpoint;
103   m_stop_info.details.signal.signo = SIGTRAP;
104 }
105 
SetStoppedByTrace()106 void NativeThreadFreeBSD::SetStoppedByTrace() {
107   SetStopped();
108   m_stop_info.reason = StopReason::eStopReasonTrace;
109   m_stop_info.details.signal.signo = SIGTRAP;
110 }
111 
SetStoppedByExec()112 void NativeThreadFreeBSD::SetStoppedByExec() {
113   SetStopped();
114   m_stop_info.reason = StopReason::eStopReasonExec;
115   m_stop_info.details.signal.signo = SIGTRAP;
116 }
117 
SetStoppedByWatchpoint(uint32_t wp_index)118 void NativeThreadFreeBSD::SetStoppedByWatchpoint(uint32_t wp_index) {
119   lldbassert(wp_index != LLDB_INVALID_INDEX32 && "wp_index cannot be invalid");
120 
121   std::ostringstream ostr;
122   ostr << GetRegisterContext().GetWatchpointAddress(wp_index) << " ";
123   ostr << wp_index;
124 
125   ostr << " " << GetRegisterContext().GetWatchpointHitAddress(wp_index);
126 
127   SetStopped();
128   m_stop_description = ostr.str();
129   m_stop_info.reason = StopReason::eStopReasonWatchpoint;
130   m_stop_info.details.signal.signo = SIGTRAP;
131 }
132 
SetStoppedByFork(lldb::pid_t child_pid,lldb::tid_t child_tid)133 void NativeThreadFreeBSD::SetStoppedByFork(lldb::pid_t child_pid,
134                                            lldb::tid_t child_tid) {
135   SetStopped();
136 
137   m_stop_info.reason = StopReason::eStopReasonFork;
138   m_stop_info.details.fork.child_pid = child_pid;
139   m_stop_info.details.fork.child_tid = child_tid;
140 }
141 
SetStoppedByVFork(lldb::pid_t child_pid,lldb::tid_t child_tid)142 void NativeThreadFreeBSD::SetStoppedByVFork(lldb::pid_t child_pid,
143                                             lldb::tid_t child_tid) {
144   SetStopped();
145 
146   m_stop_info.reason = StopReason::eStopReasonVFork;
147   m_stop_info.details.fork.child_pid = child_pid;
148   m_stop_info.details.fork.child_tid = child_tid;
149 }
150 
SetStoppedByVForkDone()151 void NativeThreadFreeBSD::SetStoppedByVForkDone() {
152   SetStopped();
153 
154   m_stop_info.reason = StopReason::eStopReasonVForkDone;
155 }
156 
SetStoppedWithNoReason()157 void NativeThreadFreeBSD::SetStoppedWithNoReason() {
158   SetStopped();
159 
160   m_stop_info.reason = StopReason::eStopReasonNone;
161   m_stop_info.details.signal.signo = 0;
162 }
163 
SetStopped()164 void NativeThreadFreeBSD::SetStopped() {
165   const StateType new_state = StateType::eStateStopped;
166   m_state = new_state;
167   m_stop_description.clear();
168 }
169 
SetRunning()170 void NativeThreadFreeBSD::SetRunning() {
171   m_state = StateType::eStateRunning;
172   m_stop_info.reason = StopReason::eStopReasonNone;
173 }
174 
SetStepping()175 void NativeThreadFreeBSD::SetStepping() {
176   m_state = StateType::eStateStepping;
177   m_stop_info.reason = StopReason::eStopReasonNone;
178 }
179 
GetName()180 std::string NativeThreadFreeBSD::GetName() {
181   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
182 
183   std::vector<struct kinfo_proc> kp;
184   int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PID | KERN_PROC_INC_THREAD,
185                 static_cast<int>(GetProcess().GetID())};
186 
187   while (1) {
188     size_t len = kp.size() * sizeof(struct kinfo_proc);
189     void *ptr = len == 0 ? nullptr : kp.data();
190     int error = ::sysctl(mib, 4, ptr, &len, nullptr, 0);
191     if (ptr == nullptr || (error != 0 && errno == ENOMEM)) {
192       kp.resize(len / sizeof(struct kinfo_proc));
193       continue;
194     }
195     if (error != 0) {
196       len = 0;
197       LLDB_LOG(log, "tid = {0} in state {1} failed to get thread name: {2}",
198                GetID(), m_state, strerror(errno));
199     }
200     kp.resize(len / sizeof(struct kinfo_proc));
201     break;
202   }
203 
204   for (auto &procinfo : kp) {
205     if (procinfo.ki_tid == static_cast<lwpid_t>(GetID()))
206       return procinfo.ki_tdname;
207   }
208 
209   return "";
210 }
211 
GetState()212 lldb::StateType NativeThreadFreeBSD::GetState() { return m_state; }
213 
GetStopReason(ThreadStopInfo & stop_info,std::string & description)214 bool NativeThreadFreeBSD::GetStopReason(ThreadStopInfo &stop_info,
215                                         std::string &description) {
216   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
217   description.clear();
218 
219   switch (m_state) {
220   case eStateStopped:
221   case eStateCrashed:
222   case eStateExited:
223   case eStateSuspended:
224   case eStateUnloaded:
225     stop_info = m_stop_info;
226     description = m_stop_description;
227 
228     return true;
229 
230   case eStateInvalid:
231   case eStateConnected:
232   case eStateAttaching:
233   case eStateLaunching:
234   case eStateRunning:
235   case eStateStepping:
236   case eStateDetached:
237     LLDB_LOG(log, "tid = {0} in state {1} cannot answer stop reason", GetID(),
238              StateAsCString(m_state));
239     return false;
240   }
241   llvm_unreachable("unhandled StateType!");
242 }
243 
GetRegisterContext()244 NativeRegisterContextFreeBSD &NativeThreadFreeBSD::GetRegisterContext() {
245   assert(m_reg_context_up);
246   return *m_reg_context_up;
247 }
248 
SetWatchpoint(lldb::addr_t addr,size_t size,uint32_t watch_flags,bool hardware)249 Status NativeThreadFreeBSD::SetWatchpoint(lldb::addr_t addr, size_t size,
250                                           uint32_t watch_flags, bool hardware) {
251   assert(m_state == eStateStopped);
252   if (!hardware)
253     return Status("not implemented");
254   Status error = RemoveWatchpoint(addr);
255   if (error.Fail())
256     return error;
257   uint32_t wp_index =
258       GetRegisterContext().SetHardwareWatchpoint(addr, size, watch_flags);
259   if (wp_index == LLDB_INVALID_INDEX32)
260     return Status("Setting hardware watchpoint failed.");
261   m_watchpoint_index_map.insert({addr, wp_index});
262   return Status();
263 }
264 
RemoveWatchpoint(lldb::addr_t addr)265 Status NativeThreadFreeBSD::RemoveWatchpoint(lldb::addr_t addr) {
266   auto wp = m_watchpoint_index_map.find(addr);
267   if (wp == m_watchpoint_index_map.end())
268     return Status();
269   uint32_t wp_index = wp->second;
270   m_watchpoint_index_map.erase(wp);
271   if (GetRegisterContext().ClearHardwareWatchpoint(wp_index))
272     return Status();
273   return Status("Clearing hardware watchpoint failed.");
274 }
275 
SetHardwareBreakpoint(lldb::addr_t addr,size_t size)276 Status NativeThreadFreeBSD::SetHardwareBreakpoint(lldb::addr_t addr,
277                                                   size_t size) {
278   assert(m_state == eStateStopped);
279   Status error = RemoveHardwareBreakpoint(addr);
280   if (error.Fail())
281     return error;
282 
283   uint32_t bp_index = GetRegisterContext().SetHardwareBreakpoint(addr, size);
284 
285   if (bp_index == LLDB_INVALID_INDEX32)
286     return Status("Setting hardware breakpoint failed.");
287 
288   m_hw_break_index_map.insert({addr, bp_index});
289   return Status();
290 }
291 
RemoveHardwareBreakpoint(lldb::addr_t addr)292 Status NativeThreadFreeBSD::RemoveHardwareBreakpoint(lldb::addr_t addr) {
293   auto bp = m_hw_break_index_map.find(addr);
294   if (bp == m_hw_break_index_map.end())
295     return Status();
296 
297   uint32_t bp_index = bp->second;
298   if (GetRegisterContext().ClearHardwareBreakpoint(bp_index)) {
299     m_hw_break_index_map.erase(bp);
300     return Status();
301   }
302 
303   return Status("Clearing hardware breakpoint failed.");
304 }
305 
306 llvm::Error
CopyWatchpointsFrom(NativeThreadFreeBSD & source)307 NativeThreadFreeBSD::CopyWatchpointsFrom(NativeThreadFreeBSD &source) {
308   llvm::Error s = GetRegisterContext().CopyHardwareWatchpointsFrom(
309       source.GetRegisterContext());
310   if (!s) {
311     m_watchpoint_index_map = source.m_watchpoint_index_map;
312     m_hw_break_index_map = source.m_hw_break_index_map;
313   }
314   return s;
315 }
316