xref: /freebsd-src/contrib/llvm-project/lldb/source/Plugins/Process/FreeBSD/NativeThreadFreeBSD.cpp (revision d409305fa3838fb39b38c26fc085fb729b8766d5)
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 
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 
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 
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 
69 Status NativeThreadFreeBSD::Suspend() {
70   Status ret = NativeProcessFreeBSD::PtraceWrapper(PT_SUSPEND, GetID());
71   if (ret.Success())
72     SetStopped();
73   return ret;
74 }
75 
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 
100 void NativeThreadFreeBSD::SetStoppedByBreakpoint() {
101   SetStopped();
102   m_stop_info.reason = StopReason::eStopReasonBreakpoint;
103   m_stop_info.details.signal.signo = SIGTRAP;
104 }
105 
106 void NativeThreadFreeBSD::SetStoppedByTrace() {
107   SetStopped();
108   m_stop_info.reason = StopReason::eStopReasonTrace;
109   m_stop_info.details.signal.signo = SIGTRAP;
110 }
111 
112 void NativeThreadFreeBSD::SetStoppedByExec() {
113   SetStopped();
114   m_stop_info.reason = StopReason::eStopReasonExec;
115   m_stop_info.details.signal.signo = SIGTRAP;
116 }
117 
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 
133 void NativeThreadFreeBSD::SetStoppedWithNoReason() {
134   SetStopped();
135 
136   m_stop_info.reason = StopReason::eStopReasonNone;
137   m_stop_info.details.signal.signo = 0;
138 }
139 
140 void NativeThreadFreeBSD::SetStopped() {
141   const StateType new_state = StateType::eStateStopped;
142   m_state = new_state;
143   m_stop_description.clear();
144 }
145 
146 void NativeThreadFreeBSD::SetRunning() {
147   m_state = StateType::eStateRunning;
148   m_stop_info.reason = StopReason::eStopReasonNone;
149 }
150 
151 void NativeThreadFreeBSD::SetStepping() {
152   m_state = StateType::eStateStepping;
153   m_stop_info.reason = StopReason::eStopReasonNone;
154 }
155 
156 std::string NativeThreadFreeBSD::GetName() {
157   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
158 
159   std::vector<struct kinfo_proc> kp;
160   int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PID | KERN_PROC_INC_THREAD,
161                 static_cast<int>(GetProcess().GetID())};
162 
163   while (1) {
164     size_t len = kp.size() * sizeof(struct kinfo_proc);
165     void *ptr = len == 0 ? nullptr : kp.data();
166     int error = ::sysctl(mib, 4, ptr, &len, nullptr, 0);
167     if (ptr == nullptr || (error != 0 && errno == ENOMEM)) {
168       kp.resize(len / sizeof(struct kinfo_proc));
169       continue;
170     }
171     if (error != 0) {
172       len = 0;
173       LLDB_LOG(log, "tid = {0} in state {1} failed to get thread name: {2}",
174                GetID(), m_state, strerror(errno));
175     }
176     kp.resize(len / sizeof(struct kinfo_proc));
177     break;
178   }
179 
180   for (auto &procinfo : kp) {
181     if (procinfo.ki_tid == static_cast<lwpid_t>(GetID()))
182       return procinfo.ki_tdname;
183   }
184 
185   return "";
186 }
187 
188 lldb::StateType NativeThreadFreeBSD::GetState() { return m_state; }
189 
190 bool NativeThreadFreeBSD::GetStopReason(ThreadStopInfo &stop_info,
191                                         std::string &description) {
192   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
193   description.clear();
194 
195   switch (m_state) {
196   case eStateStopped:
197   case eStateCrashed:
198   case eStateExited:
199   case eStateSuspended:
200   case eStateUnloaded:
201     stop_info = m_stop_info;
202     description = m_stop_description;
203 
204     return true;
205 
206   case eStateInvalid:
207   case eStateConnected:
208   case eStateAttaching:
209   case eStateLaunching:
210   case eStateRunning:
211   case eStateStepping:
212   case eStateDetached:
213     LLDB_LOG(log, "tid = {0} in state {1} cannot answer stop reason", GetID(),
214              StateAsCString(m_state));
215     return false;
216   }
217   llvm_unreachable("unhandled StateType!");
218 }
219 
220 NativeRegisterContextFreeBSD &NativeThreadFreeBSD::GetRegisterContext() {
221   assert(m_reg_context_up);
222   return *m_reg_context_up;
223 }
224 
225 Status NativeThreadFreeBSD::SetWatchpoint(lldb::addr_t addr, size_t size,
226                                           uint32_t watch_flags, bool hardware) {
227   assert(m_state == eStateStopped);
228   if (!hardware)
229     return Status("not implemented");
230   Status error = RemoveWatchpoint(addr);
231   if (error.Fail())
232     return error;
233   uint32_t wp_index =
234       GetRegisterContext().SetHardwareWatchpoint(addr, size, watch_flags);
235   if (wp_index == LLDB_INVALID_INDEX32)
236     return Status("Setting hardware watchpoint failed.");
237   m_watchpoint_index_map.insert({addr, wp_index});
238   return Status();
239 }
240 
241 Status NativeThreadFreeBSD::RemoveWatchpoint(lldb::addr_t addr) {
242   auto wp = m_watchpoint_index_map.find(addr);
243   if (wp == m_watchpoint_index_map.end())
244     return Status();
245   uint32_t wp_index = wp->second;
246   m_watchpoint_index_map.erase(wp);
247   if (GetRegisterContext().ClearHardwareWatchpoint(wp_index))
248     return Status();
249   return Status("Clearing hardware watchpoint failed.");
250 }
251 
252 Status NativeThreadFreeBSD::SetHardwareBreakpoint(lldb::addr_t addr,
253                                                   size_t size) {
254   assert(m_state == eStateStopped);
255   Status error = RemoveHardwareBreakpoint(addr);
256   if (error.Fail())
257     return error;
258 
259   uint32_t bp_index = GetRegisterContext().SetHardwareBreakpoint(addr, size);
260 
261   if (bp_index == LLDB_INVALID_INDEX32)
262     return Status("Setting hardware breakpoint failed.");
263 
264   m_hw_break_index_map.insert({addr, bp_index});
265   return Status();
266 }
267 
268 Status NativeThreadFreeBSD::RemoveHardwareBreakpoint(lldb::addr_t addr) {
269   auto bp = m_hw_break_index_map.find(addr);
270   if (bp == m_hw_break_index_map.end())
271     return Status();
272 
273   uint32_t bp_index = bp->second;
274   if (GetRegisterContext().ClearHardwareBreakpoint(bp_index)) {
275     m_hw_break_index_map.erase(bp);
276     return Status();
277   }
278 
279   return Status("Clearing hardware breakpoint failed.");
280 }
281 
282 llvm::Error
283 NativeThreadFreeBSD::CopyWatchpointsFrom(NativeThreadFreeBSD &source) {
284   llvm::Error s = GetRegisterContext().CopyHardwareWatchpointsFrom(
285       source.GetRegisterContext());
286   if (!s) {
287     m_watchpoint_index_map = source.m_watchpoint_index_map;
288     m_hw_break_index_map = source.m_hw_break_index_map;
289   }
290   return s;
291 }
292