xref: /llvm-project/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp (revision 03f12d6b224cb6691a4fee4e08adc156a3a8fd28)
1 //===-- NativeProcessLinux.cpp -------------------------------- -*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/lldb-python.h"
11 
12 #include "NativeProcessLinux.h"
13 
14 // C Includes
15 #include <errno.h>
16 #include <poll.h>
17 #include <string.h>
18 #include <stdint.h>
19 #include <unistd.h>
20 #include <linux/unistd.h>
21 #if defined(__ANDROID_NDK__) && defined (__arm__)
22 #include <linux/personality.h>
23 #include <linux/user.h>
24 #else
25 #include <sys/personality.h>
26 #include <sys/user.h>
27 #endif
28 #ifndef __ANDROID__
29 #include <sys/procfs.h>
30 #endif
31 #include <sys/ptrace.h>
32 #include <sys/uio.h>
33 #include <sys/socket.h>
34 #include <sys/syscall.h>
35 #include <sys/types.h>
36 #include <sys/wait.h>
37 
38 #if defined (__arm64__) || defined (__aarch64__)
39 // NT_PRSTATUS and NT_FPREGSET definition
40 #include <elf.h>
41 #endif
42 
43 // C++ Includes
44 #include <fstream>
45 #include <string>
46 
47 // Other libraries and framework includes
48 #include "lldb/Core/Debugger.h"
49 #include "lldb/Core/Error.h"
50 #include "lldb/Core/Module.h"
51 #include "lldb/Core/ModuleSpec.h"
52 #include "lldb/Core/RegisterValue.h"
53 #include "lldb/Core/Scalar.h"
54 #include "lldb/Core/State.h"
55 #include "lldb/Host/Host.h"
56 #include "lldb/Host/HostInfo.h"
57 #include "lldb/Host/ThreadLauncher.h"
58 #include "lldb/Symbol/ObjectFile.h"
59 #include "lldb/Target/NativeRegisterContext.h"
60 #include "lldb/Target/ProcessLaunchInfo.h"
61 #include "lldb/Utility/PseudoTerminal.h"
62 
63 #include "Host/common/NativeBreakpoint.h"
64 #include "Utility/StringExtractor.h"
65 
66 #include "Plugins/Process/Utility/LinuxSignals.h"
67 #include "NativeThreadLinux.h"
68 #include "ProcFileReader.h"
69 #include "ThreadStateCoordinator.h"
70 #include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
71 
72 #ifdef __ANDROID__
73 #define __ptrace_request int
74 #define PT_DETACH PTRACE_DETACH
75 #endif
76 
77 #define DEBUG_PTRACE_MAXBYTES 20
78 
79 // Support ptrace extensions even when compiled without required kernel support
80 #ifndef PT_GETREGS
81 #ifndef PTRACE_GETREGS
82   #define PTRACE_GETREGS 12
83 #endif
84 #endif
85 #ifndef PT_SETREGS
86 #ifndef PTRACE_SETREGS
87   #define PTRACE_SETREGS 13
88 #endif
89 #endif
90 #ifndef PT_GETFPREGS
91 #ifndef PTRACE_GETFPREGS
92   #define PTRACE_GETFPREGS 14
93 #endif
94 #endif
95 #ifndef PT_SETFPREGS
96 #ifndef PTRACE_SETFPREGS
97   #define PTRACE_SETFPREGS 15
98 #endif
99 #endif
100 #ifndef PTRACE_GETREGSET
101   #define PTRACE_GETREGSET 0x4204
102 #endif
103 #ifndef PTRACE_SETREGSET
104   #define PTRACE_SETREGSET 0x4205
105 #endif
106 #ifndef PTRACE_GET_THREAD_AREA
107   #define PTRACE_GET_THREAD_AREA 25
108 #endif
109 #ifndef PTRACE_ARCH_PRCTL
110   #define PTRACE_ARCH_PRCTL      30
111 #endif
112 #ifndef ARCH_GET_FS
113   #define ARCH_SET_GS 0x1001
114   #define ARCH_SET_FS 0x1002
115   #define ARCH_GET_FS 0x1003
116   #define ARCH_GET_GS 0x1004
117 #endif
118 
119 #define LLDB_PERSONALITY_GET_CURRENT_SETTINGS  0xffffffff
120 
121 // Support hardware breakpoints in case it has not been defined
122 #ifndef TRAP_HWBKPT
123   #define TRAP_HWBKPT 4
124 #endif
125 
126 // Try to define a macro to encapsulate the tgkill syscall
127 // fall back on kill() if tgkill isn't available
128 #define tgkill(pid, tid, sig)  syscall(SYS_tgkill, pid, tid, sig)
129 
130 // We disable the tracing of ptrace calls for integration builds to
131 // avoid the additional indirection and checks.
132 #ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
133 #define PTRACE(req, pid, addr, data, data_size) \
134     PtraceWrapper((req), (pid), (addr), (data), (data_size), #req, __FILE__, __LINE__)
135 #else
136 #define PTRACE(req, pid, addr, data, data_size) \
137     PtraceWrapper((req), (pid), (addr), (data), (data_size))
138 #endif
139 
140 // Private bits we only need internally.
141 namespace
142 {
143     using namespace lldb;
144     using namespace lldb_private;
145 
146     const UnixSignals&
147     GetUnixSignals ()
148     {
149         static process_linux::LinuxSignals signals;
150         return signals;
151     }
152 
153     ThreadStateCoordinator::LogFunction
154     GetThreadLoggerFunction ()
155     {
156         return [](const char *format, va_list args)
157         {
158             Log *const log = GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD);
159             if (log)
160                 log->VAPrintf (format, args);
161         };
162     }
163 
164     void
165     CoordinatorErrorHandler (const std::string &error_message)
166     {
167         Log *const log = GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD);
168         if (log)
169             log->Printf ("NativePlatformLinux::%s ThreadStateCoordinator error received: %s", __FUNCTION__, error_message.c_str ());
170         assert (false && "ThreadStateCoordinator error reported");
171     }
172 
173     Error
174     ResolveProcessArchitecture (lldb::pid_t pid, Platform &platform, ArchSpec &arch)
175     {
176         // Grab process info for the running process.
177         ProcessInstanceInfo process_info;
178         if (!platform.GetProcessInfo (pid, process_info))
179             return lldb_private::Error("failed to get process info");
180 
181         // Resolve the executable module.
182         ModuleSP exe_module_sp;
183         ModuleSpec exe_module_spec(process_info.GetExecutableFile(), platform.GetSystemArchitecture ());
184         FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths ());
185         Error error = platform.ResolveExecutable(
186             exe_module_spec,
187             exe_module_sp,
188             executable_search_paths.GetSize () ? &executable_search_paths : NULL);
189 
190         if (!error.Success ())
191             return error;
192 
193         // Check if we've got our architecture from the exe_module.
194         arch = exe_module_sp->GetArchitecture ();
195         if (arch.IsValid ())
196             return Error();
197         else
198             return Error("failed to retrieve a valid architecture from the exe module");
199     }
200 
201     void
202     DisplayBytes (lldb_private::StreamString &s, void *bytes, uint32_t count)
203     {
204         uint8_t *ptr = (uint8_t *)bytes;
205         const uint32_t loop_count = std::min<uint32_t>(DEBUG_PTRACE_MAXBYTES, count);
206         for(uint32_t i=0; i<loop_count; i++)
207         {
208             s.Printf ("[%x]", *ptr);
209             ptr++;
210         }
211     }
212 
213     void
214     PtraceDisplayBytes(int &req, void *data, size_t data_size)
215     {
216         StreamString buf;
217         Log *verbose_log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (
218                     POSIX_LOG_PTRACE | POSIX_LOG_VERBOSE));
219 
220         if (verbose_log)
221         {
222             switch(req)
223             {
224             case PTRACE_POKETEXT:
225             {
226                 DisplayBytes(buf, &data, 8);
227                 verbose_log->Printf("PTRACE_POKETEXT %s", buf.GetData());
228                 break;
229             }
230             case PTRACE_POKEDATA:
231             {
232                 DisplayBytes(buf, &data, 8);
233                 verbose_log->Printf("PTRACE_POKEDATA %s", buf.GetData());
234                 break;
235             }
236             case PTRACE_POKEUSER:
237             {
238                 DisplayBytes(buf, &data, 8);
239                 verbose_log->Printf("PTRACE_POKEUSER %s", buf.GetData());
240                 break;
241             }
242             case PTRACE_SETREGS:
243             {
244                 DisplayBytes(buf, data, data_size);
245                 verbose_log->Printf("PTRACE_SETREGS %s", buf.GetData());
246                 break;
247             }
248             case PTRACE_SETFPREGS:
249             {
250                 DisplayBytes(buf, data, data_size);
251                 verbose_log->Printf("PTRACE_SETFPREGS %s", buf.GetData());
252                 break;
253             }
254             case PTRACE_SETSIGINFO:
255             {
256                 DisplayBytes(buf, data, sizeof(siginfo_t));
257                 verbose_log->Printf("PTRACE_SETSIGINFO %s", buf.GetData());
258                 break;
259             }
260             case PTRACE_SETREGSET:
261             {
262                 // Extract iov_base from data, which is a pointer to the struct IOVEC
263                 DisplayBytes(buf, *(void **)data, data_size);
264                 verbose_log->Printf("PTRACE_SETREGSET %s", buf.GetData());
265                 break;
266             }
267             default:
268             {
269             }
270             }
271         }
272     }
273 
274     // Wrapper for ptrace to catch errors and log calls.
275     // Note that ptrace sets errno on error because -1 can be a valid result (i.e. for PTRACE_PEEK*)
276     long
277     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size,
278             const char* reqName, const char* file, int line)
279     {
280         long int result;
281 
282         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PTRACE));
283 
284         PtraceDisplayBytes(req, data, data_size);
285 
286         errno = 0;
287         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
288             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
289         else
290             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
291 
292         if (log)
293             log->Printf("ptrace(%s, %" PRIu64 ", %p, %p, %zu)=%lX called from file %s line %d",
294                     reqName, pid, addr, data, data_size, result, file, line);
295 
296         PtraceDisplayBytes(req, data, data_size);
297 
298         if (log && errno != 0)
299         {
300             const char* str;
301             switch (errno)
302             {
303             case ESRCH:  str = "ESRCH"; break;
304             case EINVAL: str = "EINVAL"; break;
305             case EBUSY:  str = "EBUSY"; break;
306             case EPERM:  str = "EPERM"; break;
307             default:     str = "<unknown>";
308             }
309             log->Printf("ptrace() failed; errno=%d (%s)", errno, str);
310         }
311 
312         return result;
313     }
314 
315 #ifdef LLDB_CONFIGURATION_BUILDANDINTEGRATION
316     // Wrapper for ptrace when logging is not required.
317     // Sets errno to 0 prior to calling ptrace.
318     long
319     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size)
320     {
321         long result = 0;
322         errno = 0;
323         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
324             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
325         else
326             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
327         return result;
328     }
329 #endif
330 
331     //------------------------------------------------------------------------------
332     // Static implementations of NativeProcessLinux::ReadMemory and
333     // NativeProcessLinux::WriteMemory.  This enables mutual recursion between these
334     // functions without needed to go thru the thread funnel.
335 
336     static lldb::addr_t
337     DoReadMemory (
338         lldb::pid_t pid,
339         lldb::addr_t vm_addr,
340         void *buf,
341         lldb::addr_t size,
342         Error &error)
343     {
344         // ptrace word size is determined by the host, not the child
345         static const unsigned word_size = sizeof(void*);
346         unsigned char *dst = static_cast<unsigned char*>(buf);
347         lldb::addr_t bytes_read;
348         lldb::addr_t remainder;
349         long data;
350 
351         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
352         if (log)
353             ProcessPOSIXLog::IncNestLevel();
354         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
355             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %d, %p, %p, %zd, _)", __FUNCTION__,
356                     pid, word_size, (void*)vm_addr, buf, size);
357 
358         assert(sizeof(data) >= word_size);
359         for (bytes_read = 0; bytes_read < size; bytes_read += remainder)
360         {
361             errno = 0;
362             data = PTRACE(PTRACE_PEEKDATA, pid, (void*)vm_addr, NULL, 0);
363             if (errno)
364             {
365                 error.SetErrorToErrno();
366                 if (log)
367                     ProcessPOSIXLog::DecNestLevel();
368                 return bytes_read;
369             }
370 
371             remainder = size - bytes_read;
372             remainder = remainder > word_size ? word_size : remainder;
373 
374             // Copy the data into our buffer
375             for (unsigned i = 0; i < remainder; ++i)
376                 dst[i] = ((data >> i*8) & 0xFF);
377 
378             if (log && ProcessPOSIXLog::AtTopNestLevel() &&
379                     (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
380                             (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
381                                     size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
382             {
383                 uintptr_t print_dst = 0;
384                 // Format bytes from data by moving into print_dst for log output
385                 for (unsigned i = 0; i < remainder; ++i)
386                     print_dst |= (((data >> i*8) & 0xFF) << i*8);
387                 log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
388                         (void*)vm_addr, print_dst, (unsigned long)data);
389             }
390 
391             vm_addr += word_size;
392             dst += word_size;
393         }
394 
395         if (log)
396             ProcessPOSIXLog::DecNestLevel();
397         return bytes_read;
398     }
399 
400     static lldb::addr_t
401     DoWriteMemory(
402         lldb::pid_t pid,
403         lldb::addr_t vm_addr,
404         const void *buf,
405         lldb::addr_t size,
406         Error &error)
407     {
408         // ptrace word size is determined by the host, not the child
409         static const unsigned word_size = sizeof(void*);
410         const unsigned char *src = static_cast<const unsigned char*>(buf);
411         lldb::addr_t bytes_written = 0;
412         lldb::addr_t remainder;
413 
414         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
415         if (log)
416             ProcessPOSIXLog::IncNestLevel();
417         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
418             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %u, %p, %p, %" PRIu64 ")", __FUNCTION__,
419                     pid, word_size, (void*)vm_addr, buf, size);
420 
421         for (bytes_written = 0; bytes_written < size; bytes_written += remainder)
422         {
423             remainder = size - bytes_written;
424             remainder = remainder > word_size ? word_size : remainder;
425 
426             if (remainder == word_size)
427             {
428                 unsigned long data = 0;
429                 assert(sizeof(data) >= word_size);
430                 for (unsigned i = 0; i < word_size; ++i)
431                     data |= (unsigned long)src[i] << i*8;
432 
433                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
434                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
435                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
436                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
437                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
438                             (void*)vm_addr, *(unsigned long*)src, data);
439 
440                 if (PTRACE(PTRACE_POKEDATA, pid, (void*)vm_addr, (void*)data, 0))
441                 {
442                     error.SetErrorToErrno();
443                     if (log)
444                         ProcessPOSIXLog::DecNestLevel();
445                     return bytes_written;
446                 }
447             }
448             else
449             {
450                 unsigned char buff[8];
451                 if (DoReadMemory(pid, vm_addr,
452                                 buff, word_size, error) != word_size)
453                 {
454                     if (log)
455                         ProcessPOSIXLog::DecNestLevel();
456                     return bytes_written;
457                 }
458 
459                 memcpy(buff, src, remainder);
460 
461                 if (DoWriteMemory(pid, vm_addr,
462                                 buff, word_size, error) != word_size)
463                 {
464                     if (log)
465                         ProcessPOSIXLog::DecNestLevel();
466                     return bytes_written;
467                 }
468 
469                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
470                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
471                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
472                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
473                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
474                             (void*)vm_addr, *(unsigned long*)src, *(unsigned long*)buff);
475             }
476 
477             vm_addr += word_size;
478             src += word_size;
479         }
480         if (log)
481             ProcessPOSIXLog::DecNestLevel();
482         return bytes_written;
483     }
484 
485     //------------------------------------------------------------------------------
486     /// @class Operation
487     /// @brief Represents a NativeProcessLinux operation.
488     ///
489     /// Under Linux, it is not possible to ptrace() from any other thread but the
490     /// one that spawned or attached to the process from the start.  Therefore, when
491     /// a NativeProcessLinux is asked to deliver or change the state of an inferior
492     /// process the operation must be "funneled" to a specific thread to perform the
493     /// task.  The Operation class provides an abstract base for all services the
494     /// NativeProcessLinux must perform via the single virtual function Execute, thus
495     /// encapsulating the code that needs to run in the privileged context.
496     class Operation
497     {
498     public:
499         Operation () : m_error() { }
500 
501         virtual
502         ~Operation() {}
503 
504         virtual void
505         Execute (NativeProcessLinux *process) = 0;
506 
507         const Error &
508         GetError () const { return m_error; }
509 
510     protected:
511         Error m_error;
512     };
513 
514     //------------------------------------------------------------------------------
515     /// @class ReadOperation
516     /// @brief Implements NativeProcessLinux::ReadMemory.
517     class ReadOperation : public Operation
518     {
519     public:
520         ReadOperation (
521             lldb::addr_t addr,
522             void *buff,
523             lldb::addr_t size,
524             lldb::addr_t &result) :
525             Operation (),
526             m_addr (addr),
527             m_buff (buff),
528             m_size (size),
529             m_result (result)
530             {
531             }
532 
533         void Execute (NativeProcessLinux *process) override;
534 
535     private:
536         lldb::addr_t m_addr;
537         void *m_buff;
538         lldb::addr_t m_size;
539         lldb::addr_t &m_result;
540     };
541 
542     void
543     ReadOperation::Execute (NativeProcessLinux *process)
544     {
545         m_result = DoReadMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
546     }
547 
548     //------------------------------------------------------------------------------
549     /// @class WriteOperation
550     /// @brief Implements NativeProcessLinux::WriteMemory.
551     class WriteOperation : public Operation
552     {
553     public:
554         WriteOperation (
555             lldb::addr_t addr,
556             const void *buff,
557             lldb::addr_t size,
558             lldb::addr_t &result) :
559             Operation (),
560             m_addr (addr),
561             m_buff (buff),
562             m_size (size),
563             m_result (result)
564             {
565             }
566 
567         void Execute (NativeProcessLinux *process) override;
568 
569     private:
570         lldb::addr_t m_addr;
571         const void *m_buff;
572         lldb::addr_t m_size;
573         lldb::addr_t &m_result;
574     };
575 
576     void
577     WriteOperation::Execute(NativeProcessLinux *process)
578     {
579         m_result = DoWriteMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
580     }
581 
582     //------------------------------------------------------------------------------
583     /// @class ReadRegOperation
584     /// @brief Implements NativeProcessLinux::ReadRegisterValue.
585     class ReadRegOperation : public Operation
586     {
587     public:
588         ReadRegOperation(lldb::tid_t tid, uint32_t offset, const char *reg_name,
589                 RegisterValue &value, bool &result)
590             : m_tid(tid), m_offset(static_cast<uintptr_t> (offset)), m_reg_name(reg_name),
591               m_value(value), m_result(result)
592             { }
593 
594         void Execute(NativeProcessLinux *monitor);
595 
596     private:
597         lldb::tid_t m_tid;
598         uintptr_t m_offset;
599         const char *m_reg_name;
600         RegisterValue &m_value;
601         bool &m_result;
602     };
603 
604     void
605     ReadRegOperation::Execute(NativeProcessLinux *monitor)
606     {
607 #if defined (__arm64__) || defined (__aarch64__)
608         if (m_offset > sizeof(struct user_pt_regs))
609         {
610             uintptr_t offset = m_offset - sizeof(struct user_pt_regs);
611             if (offset > sizeof(struct user_fpsimd_state))
612             {
613                 m_result = false;
614             }
615             else
616             {
617                 elf_fpregset_t regs;
618                 int regset = NT_FPREGSET;
619                 struct iovec ioVec;
620 
621                 ioVec.iov_base = &regs;
622                 ioVec.iov_len = sizeof regs;
623                 if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
624                     m_result = false;
625                 else
626                 {
627                     lldb_private::ArchSpec arch;
628                     if (monitor->GetArchitecture(arch))
629                     {
630                         m_result = true;
631                         m_value.SetBytes((void *)(((unsigned char *)(&regs)) + offset), 16, arch.GetByteOrder());
632                     }
633                     else
634                         m_result = false;
635                 }
636             }
637         }
638         else
639         {
640             elf_gregset_t regs;
641             int regset = NT_PRSTATUS;
642             struct iovec ioVec;
643 
644             ioVec.iov_base = &regs;
645             ioVec.iov_len = sizeof regs;
646             if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
647                 m_result = false;
648             else
649             {
650                 lldb_private::ArchSpec arch;
651                 if (monitor->GetArchitecture(arch))
652                 {
653                     m_result = true;
654                     m_value.SetBytes((void *)(((unsigned char *)(regs)) + m_offset), 8, arch.GetByteOrder());
655                 } else
656                     m_result = false;
657             }
658         }
659 #else
660         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
661 
662         // Set errno to zero so that we can detect a failed peek.
663         errno = 0;
664         lldb::addr_t data = PTRACE(PTRACE_PEEKUSER, m_tid, (void*)m_offset, NULL, 0);
665         if (errno)
666             m_result = false;
667         else
668         {
669             m_value = data;
670             m_result = true;
671         }
672         if (log)
673             log->Printf ("NativeProcessLinux::%s() reg %s: 0x%" PRIx64, __FUNCTION__,
674                     m_reg_name, data);
675 #endif
676     }
677 
678     //------------------------------------------------------------------------------
679     /// @class WriteRegOperation
680     /// @brief Implements NativeProcessLinux::WriteRegisterValue.
681     class WriteRegOperation : public Operation
682     {
683     public:
684         WriteRegOperation(lldb::tid_t tid, unsigned offset, const char *reg_name,
685                 const RegisterValue &value, bool &result)
686             : m_tid(tid), m_offset(offset), m_reg_name(reg_name),
687               m_value(value), m_result(result)
688             { }
689 
690         void Execute(NativeProcessLinux *monitor);
691 
692     private:
693         lldb::tid_t m_tid;
694         uintptr_t m_offset;
695         const char *m_reg_name;
696         const RegisterValue &m_value;
697         bool &m_result;
698     };
699 
700     void
701     WriteRegOperation::Execute(NativeProcessLinux *monitor)
702     {
703 #if defined (__arm64__) || defined (__aarch64__)
704         if (m_offset > sizeof(struct user_pt_regs))
705         {
706             uintptr_t offset = m_offset - sizeof(struct user_pt_regs);
707             if (offset > sizeof(struct user_fpsimd_state))
708             {
709                 m_result = false;
710             }
711             else
712             {
713                 elf_fpregset_t regs;
714                 int regset = NT_FPREGSET;
715                 struct iovec ioVec;
716 
717                 ioVec.iov_base = &regs;
718                 ioVec.iov_len = sizeof regs;
719                 if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
720                     m_result = false;
721                 else
722                 {
723                     ::memcpy((void *)(((unsigned char *)(&regs)) + offset), m_value.GetBytes(), 16);
724                     if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
725                         m_result = false;
726                     else
727                         m_result = true;
728                 }
729             }
730         }
731         else
732         {
733             elf_gregset_t regs;
734             int regset = NT_PRSTATUS;
735             struct iovec ioVec;
736 
737             ioVec.iov_base = &regs;
738             ioVec.iov_len = sizeof regs;
739             if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
740                 m_result = false;
741             else
742             {
743                 ::memcpy((void *)(((unsigned char *)(&regs)) + m_offset), m_value.GetBytes(), 8);
744                 if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
745                     m_result = false;
746                 else
747                     m_result = true;
748             }
749         }
750 #else
751         void* buf;
752         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
753 
754         buf = (void*) m_value.GetAsUInt64();
755 
756         if (log)
757             log->Printf ("NativeProcessLinux::%s() reg %s: %p", __FUNCTION__, m_reg_name, buf);
758         if (PTRACE(PTRACE_POKEUSER, m_tid, (void*)m_offset, buf, 0))
759             m_result = false;
760         else
761             m_result = true;
762 #endif
763     }
764 
765     //------------------------------------------------------------------------------
766     /// @class ReadGPROperation
767     /// @brief Implements NativeProcessLinux::ReadGPR.
768     class ReadGPROperation : public Operation
769     {
770     public:
771         ReadGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
772             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
773             { }
774 
775         void Execute(NativeProcessLinux *monitor);
776 
777     private:
778         lldb::tid_t m_tid;
779         void *m_buf;
780         size_t m_buf_size;
781         bool &m_result;
782     };
783 
784     void
785     ReadGPROperation::Execute(NativeProcessLinux *monitor)
786     {
787 #if defined (__arm64__) || defined (__aarch64__)
788         int regset = NT_PRSTATUS;
789         struct iovec ioVec;
790 
791         ioVec.iov_base = m_buf;
792         ioVec.iov_len = m_buf_size;
793         if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
794             m_result = false;
795         else
796             m_result = true;
797 #else
798         if (PTRACE(PTRACE_GETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
799             m_result = false;
800         else
801             m_result = true;
802 #endif
803     }
804 
805     //------------------------------------------------------------------------------
806     /// @class ReadFPROperation
807     /// @brief Implements NativeProcessLinux::ReadFPR.
808     class ReadFPROperation : public Operation
809     {
810     public:
811         ReadFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
812             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
813             { }
814 
815         void Execute(NativeProcessLinux *monitor);
816 
817     private:
818         lldb::tid_t m_tid;
819         void *m_buf;
820         size_t m_buf_size;
821         bool &m_result;
822     };
823 
824     void
825     ReadFPROperation::Execute(NativeProcessLinux *monitor)
826     {
827 #if defined (__arm64__) || defined (__aarch64__)
828         int regset = NT_FPREGSET;
829         struct iovec ioVec;
830 
831         ioVec.iov_base = m_buf;
832         ioVec.iov_len = m_buf_size;
833         if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
834             m_result = false;
835         else
836             m_result = true;
837 #else
838         if (PTRACE(PTRACE_GETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
839             m_result = false;
840         else
841             m_result = true;
842 #endif
843     }
844 
845     //------------------------------------------------------------------------------
846     /// @class ReadRegisterSetOperation
847     /// @brief Implements NativeProcessLinux::ReadRegisterSet.
848     class ReadRegisterSetOperation : public Operation
849     {
850     public:
851         ReadRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
852             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
853             { }
854 
855         void Execute(NativeProcessLinux *monitor);
856 
857     private:
858         lldb::tid_t m_tid;
859         void *m_buf;
860         size_t m_buf_size;
861         const unsigned int m_regset;
862         bool &m_result;
863     };
864 
865     void
866     ReadRegisterSetOperation::Execute(NativeProcessLinux *monitor)
867     {
868         if (PTRACE(PTRACE_GETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
869             m_result = false;
870         else
871             m_result = true;
872     }
873 
874     //------------------------------------------------------------------------------
875     /// @class WriteGPROperation
876     /// @brief Implements NativeProcessLinux::WriteGPR.
877     class WriteGPROperation : public Operation
878     {
879     public:
880         WriteGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
881             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
882             { }
883 
884         void Execute(NativeProcessLinux *monitor);
885 
886     private:
887         lldb::tid_t m_tid;
888         void *m_buf;
889         size_t m_buf_size;
890         bool &m_result;
891     };
892 
893     void
894     WriteGPROperation::Execute(NativeProcessLinux *monitor)
895     {
896 #if defined (__arm64__) || defined (__aarch64__)
897         int regset = NT_PRSTATUS;
898         struct iovec ioVec;
899 
900         ioVec.iov_base = m_buf;
901         ioVec.iov_len = m_buf_size;
902         if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
903             m_result = false;
904         else
905             m_result = true;
906 #else
907         if (PTRACE(PTRACE_SETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
908             m_result = false;
909         else
910             m_result = true;
911 #endif
912     }
913 
914     //------------------------------------------------------------------------------
915     /// @class WriteFPROperation
916     /// @brief Implements NativeProcessLinux::WriteFPR.
917     class WriteFPROperation : public Operation
918     {
919     public:
920         WriteFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
921             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
922             { }
923 
924         void Execute(NativeProcessLinux *monitor);
925 
926     private:
927         lldb::tid_t m_tid;
928         void *m_buf;
929         size_t m_buf_size;
930         bool &m_result;
931     };
932 
933     void
934     WriteFPROperation::Execute(NativeProcessLinux *monitor)
935     {
936 #if defined (__arm64__) || defined (__aarch64__)
937         int regset = NT_FPREGSET;
938         struct iovec ioVec;
939 
940         ioVec.iov_base = m_buf;
941         ioVec.iov_len = m_buf_size;
942         if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
943             m_result = false;
944         else
945             m_result = true;
946 #else
947         if (PTRACE(PTRACE_SETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
948             m_result = false;
949         else
950             m_result = true;
951 #endif
952     }
953 
954     //------------------------------------------------------------------------------
955     /// @class WriteRegisterSetOperation
956     /// @brief Implements NativeProcessLinux::WriteRegisterSet.
957     class WriteRegisterSetOperation : public Operation
958     {
959     public:
960         WriteRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
961             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
962             { }
963 
964         void Execute(NativeProcessLinux *monitor);
965 
966     private:
967         lldb::tid_t m_tid;
968         void *m_buf;
969         size_t m_buf_size;
970         const unsigned int m_regset;
971         bool &m_result;
972     };
973 
974     void
975     WriteRegisterSetOperation::Execute(NativeProcessLinux *monitor)
976     {
977         if (PTRACE(PTRACE_SETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
978             m_result = false;
979         else
980             m_result = true;
981     }
982 
983     //------------------------------------------------------------------------------
984     /// @class ResumeOperation
985     /// @brief Implements NativeProcessLinux::Resume.
986     class ResumeOperation : public Operation
987     {
988     public:
989         ResumeOperation(lldb::tid_t tid, uint32_t signo, bool &result) :
990             m_tid(tid), m_signo(signo), m_result(result) { }
991 
992         void Execute(NativeProcessLinux *monitor);
993 
994     private:
995         lldb::tid_t m_tid;
996         uint32_t m_signo;
997         bool &m_result;
998     };
999 
1000     void
1001     ResumeOperation::Execute(NativeProcessLinux *monitor)
1002     {
1003         intptr_t data = 0;
1004 
1005         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
1006             data = m_signo;
1007 
1008         if (PTRACE(PTRACE_CONT, m_tid, NULL, (void*)data, 0))
1009         {
1010             Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1011 
1012             if (log)
1013                 log->Printf ("ResumeOperation (%"  PRIu64 ") failed: %s", m_tid, strerror(errno));
1014             m_result = false;
1015         }
1016         else
1017             m_result = true;
1018     }
1019 
1020     //------------------------------------------------------------------------------
1021     /// @class SingleStepOperation
1022     /// @brief Implements NativeProcessLinux::SingleStep.
1023     class SingleStepOperation : public Operation
1024     {
1025     public:
1026         SingleStepOperation(lldb::tid_t tid, uint32_t signo, bool &result)
1027             : m_tid(tid), m_signo(signo), m_result(result) { }
1028 
1029         void Execute(NativeProcessLinux *monitor);
1030 
1031     private:
1032         lldb::tid_t m_tid;
1033         uint32_t m_signo;
1034         bool &m_result;
1035     };
1036 
1037     void
1038     SingleStepOperation::Execute(NativeProcessLinux *monitor)
1039     {
1040         intptr_t data = 0;
1041 
1042         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
1043             data = m_signo;
1044 
1045         if (PTRACE(PTRACE_SINGLESTEP, m_tid, NULL, (void*)data, 0))
1046             m_result = false;
1047         else
1048             m_result = true;
1049     }
1050 
1051     //------------------------------------------------------------------------------
1052     /// @class SiginfoOperation
1053     /// @brief Implements NativeProcessLinux::GetSignalInfo.
1054     class SiginfoOperation : public Operation
1055     {
1056     public:
1057         SiginfoOperation(lldb::tid_t tid, void *info, bool &result, int &ptrace_err)
1058             : m_tid(tid), m_info(info), m_result(result), m_err(ptrace_err) { }
1059 
1060         void Execute(NativeProcessLinux *monitor);
1061 
1062     private:
1063         lldb::tid_t m_tid;
1064         void *m_info;
1065         bool &m_result;
1066         int &m_err;
1067     };
1068 
1069     void
1070     SiginfoOperation::Execute(NativeProcessLinux *monitor)
1071     {
1072         if (PTRACE(PTRACE_GETSIGINFO, m_tid, NULL, m_info, 0)) {
1073             m_result = false;
1074             m_err = errno;
1075         }
1076         else
1077             m_result = true;
1078     }
1079 
1080     //------------------------------------------------------------------------------
1081     /// @class EventMessageOperation
1082     /// @brief Implements NativeProcessLinux::GetEventMessage.
1083     class EventMessageOperation : public Operation
1084     {
1085     public:
1086         EventMessageOperation(lldb::tid_t tid, unsigned long *message, bool &result)
1087             : m_tid(tid), m_message(message), m_result(result) { }
1088 
1089         void Execute(NativeProcessLinux *monitor);
1090 
1091     private:
1092         lldb::tid_t m_tid;
1093         unsigned long *m_message;
1094         bool &m_result;
1095     };
1096 
1097     void
1098     EventMessageOperation::Execute(NativeProcessLinux *monitor)
1099     {
1100         if (PTRACE(PTRACE_GETEVENTMSG, m_tid, NULL, m_message, 0))
1101             m_result = false;
1102         else
1103             m_result = true;
1104     }
1105 
1106     class DetachOperation : public Operation
1107     {
1108     public:
1109         DetachOperation(lldb::tid_t tid, Error &result) : m_tid(tid), m_error(result) { }
1110 
1111         void Execute(NativeProcessLinux *monitor);
1112 
1113     private:
1114         lldb::tid_t m_tid;
1115         Error &m_error;
1116     };
1117 
1118     void
1119     DetachOperation::Execute(NativeProcessLinux *monitor)
1120     {
1121         if (ptrace(PT_DETACH, m_tid, NULL, 0) < 0)
1122             m_error.SetErrorToErrno();
1123     }
1124 
1125 }
1126 
1127 using namespace lldb_private;
1128 
1129 // Simple helper function to ensure flags are enabled on the given file
1130 // descriptor.
1131 static bool
1132 EnsureFDFlags(int fd, int flags, Error &error)
1133 {
1134     int status;
1135 
1136     if ((status = fcntl(fd, F_GETFL)) == -1)
1137     {
1138         error.SetErrorToErrno();
1139         return false;
1140     }
1141 
1142     if (fcntl(fd, F_SETFL, status | flags) == -1)
1143     {
1144         error.SetErrorToErrno();
1145         return false;
1146     }
1147 
1148     return true;
1149 }
1150 
1151 NativeProcessLinux::OperationArgs::OperationArgs(NativeProcessLinux *monitor)
1152     : m_monitor(monitor)
1153 {
1154     sem_init(&m_semaphore, 0, 0);
1155 }
1156 
1157 NativeProcessLinux::OperationArgs::~OperationArgs()
1158 {
1159     sem_destroy(&m_semaphore);
1160 }
1161 
1162 NativeProcessLinux::LaunchArgs::LaunchArgs(NativeProcessLinux *monitor,
1163                                        lldb_private::Module *module,
1164                                        char const **argv,
1165                                        char const **envp,
1166                                        const std::string &stdin_path,
1167                                        const std::string &stdout_path,
1168                                        const std::string &stderr_path,
1169                                        const char *working_dir,
1170                                        const lldb_private::ProcessLaunchInfo &launch_info)
1171     : OperationArgs(monitor),
1172       m_module(module),
1173       m_argv(argv),
1174       m_envp(envp),
1175       m_stdin_path(stdin_path),
1176       m_stdout_path(stdout_path),
1177       m_stderr_path(stderr_path),
1178       m_working_dir(working_dir),
1179       m_launch_info(launch_info)
1180 {
1181 }
1182 
1183 NativeProcessLinux::LaunchArgs::~LaunchArgs()
1184 { }
1185 
1186 NativeProcessLinux::AttachArgs::AttachArgs(NativeProcessLinux *monitor,
1187                                        lldb::pid_t pid)
1188     : OperationArgs(monitor), m_pid(pid) { }
1189 
1190 NativeProcessLinux::AttachArgs::~AttachArgs()
1191 { }
1192 
1193 // -----------------------------------------------------------------------------
1194 // Public Static Methods
1195 // -----------------------------------------------------------------------------
1196 
1197 lldb_private::Error
1198 NativeProcessLinux::LaunchProcess (
1199     lldb_private::Module *exe_module,
1200     lldb_private::ProcessLaunchInfo &launch_info,
1201     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1202     NativeProcessProtocolSP &native_process_sp)
1203 {
1204     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1205 
1206     Error error;
1207 
1208     // Verify the working directory is valid if one was specified.
1209     const char* working_dir = launch_info.GetWorkingDirectory ();
1210     if (working_dir)
1211     {
1212       FileSpec working_dir_fs (working_dir, true);
1213       if (!working_dir_fs || working_dir_fs.GetFileType () != FileSpec::eFileTypeDirectory)
1214       {
1215           error.SetErrorStringWithFormat ("No such file or directory: %s", working_dir);
1216           return error;
1217       }
1218     }
1219 
1220     const lldb_private::FileAction *file_action;
1221 
1222     // Default of NULL will mean to use existing open file descriptors.
1223     std::string stdin_path;
1224     std::string stdout_path;
1225     std::string stderr_path;
1226 
1227     file_action = launch_info.GetFileActionForFD (STDIN_FILENO);
1228     if (file_action)
1229         stdin_path = file_action->GetPath ();
1230 
1231     file_action = launch_info.GetFileActionForFD (STDOUT_FILENO);
1232     if (file_action)
1233         stdout_path = file_action->GetPath ();
1234 
1235     file_action = launch_info.GetFileActionForFD (STDERR_FILENO);
1236     if (file_action)
1237         stderr_path = file_action->GetPath ();
1238 
1239     if (log)
1240     {
1241         if (!stdin_path.empty ())
1242             log->Printf ("NativeProcessLinux::%s setting STDIN to '%s'", __FUNCTION__, stdin_path.c_str ());
1243         else
1244             log->Printf ("NativeProcessLinux::%s leaving STDIN as is", __FUNCTION__);
1245 
1246         if (!stdout_path.empty ())
1247             log->Printf ("NativeProcessLinux::%s setting STDOUT to '%s'", __FUNCTION__, stdout_path.c_str ());
1248         else
1249             log->Printf ("NativeProcessLinux::%s leaving STDOUT as is", __FUNCTION__);
1250 
1251         if (!stderr_path.empty ())
1252             log->Printf ("NativeProcessLinux::%s setting STDERR to '%s'", __FUNCTION__, stderr_path.c_str ());
1253         else
1254             log->Printf ("NativeProcessLinux::%s leaving STDERR as is", __FUNCTION__);
1255     }
1256 
1257     // Create the NativeProcessLinux in launch mode.
1258     native_process_sp.reset (new NativeProcessLinux ());
1259 
1260     if (log)
1261     {
1262         int i = 0;
1263         for (const char **args = launch_info.GetArguments ().GetConstArgumentVector (); *args; ++args, ++i)
1264         {
1265             log->Printf ("NativeProcessLinux::%s arg %d: \"%s\"", __FUNCTION__, i, *args ? *args : "nullptr");
1266             ++i;
1267         }
1268     }
1269 
1270     if (!native_process_sp->RegisterNativeDelegate (native_delegate))
1271     {
1272         native_process_sp.reset ();
1273         error.SetErrorStringWithFormat ("failed to register the native delegate");
1274         return error;
1275     }
1276 
1277     reinterpret_cast<NativeProcessLinux*> (native_process_sp.get ())->LaunchInferior (
1278             exe_module,
1279             launch_info.GetArguments ().GetConstArgumentVector (),
1280             launch_info.GetEnvironmentEntries ().GetConstArgumentVector (),
1281             stdin_path,
1282             stdout_path,
1283             stderr_path,
1284             working_dir,
1285             launch_info,
1286             error);
1287 
1288     if (error.Fail ())
1289     {
1290         native_process_sp.reset ();
1291         if (log)
1292             log->Printf ("NativeProcessLinux::%s failed to launch process: %s", __FUNCTION__, error.AsCString ());
1293         return error;
1294     }
1295 
1296     launch_info.SetProcessID (native_process_sp->GetID ());
1297 
1298     return error;
1299 }
1300 
1301 lldb_private::Error
1302 NativeProcessLinux::AttachToProcess (
1303     lldb::pid_t pid,
1304     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1305     NativeProcessProtocolSP &native_process_sp)
1306 {
1307     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1308     if (log && log->GetMask ().Test (POSIX_LOG_VERBOSE))
1309         log->Printf ("NativeProcessLinux::%s(pid = %" PRIi64 ")", __FUNCTION__, pid);
1310 
1311     // Grab the current platform architecture.  This should be Linux,
1312     // since this code is only intended to run on a Linux host.
1313     PlatformSP platform_sp (Platform::GetHostPlatform ());
1314     if (!platform_sp)
1315         return Error("failed to get a valid default platform");
1316 
1317     // Retrieve the architecture for the running process.
1318     ArchSpec process_arch;
1319     Error error = ResolveProcessArchitecture (pid, *platform_sp.get (), process_arch);
1320     if (!error.Success ())
1321         return error;
1322 
1323     std::shared_ptr<NativeProcessLinux> native_process_linux_sp (new NativeProcessLinux ());
1324 
1325     if (!native_process_linux_sp->RegisterNativeDelegate (native_delegate))
1326     {
1327         error.SetErrorStringWithFormat ("failed to register the native delegate");
1328         return error;
1329     }
1330 
1331     native_process_linux_sp->AttachToInferior (pid, error);
1332     if (!error.Success ())
1333         return error;
1334 
1335     native_process_sp = native_process_linux_sp;
1336     return error;
1337 }
1338 
1339 // -----------------------------------------------------------------------------
1340 // Public Instance Methods
1341 // -----------------------------------------------------------------------------
1342 
1343 NativeProcessLinux::NativeProcessLinux () :
1344     NativeProcessProtocol (LLDB_INVALID_PROCESS_ID),
1345     m_arch (),
1346     m_operation_thread (),
1347     m_monitor_thread (),
1348     m_operation (nullptr),
1349     m_operation_mutex (),
1350     m_operation_pending (),
1351     m_operation_done (),
1352     m_supports_mem_region (eLazyBoolCalculate),
1353     m_mem_region_cache (),
1354     m_mem_region_cache_mutex (),
1355     m_coordinator_up (new ThreadStateCoordinator (GetThreadLoggerFunction ())),
1356     m_coordinator_thread ()
1357 {
1358 }
1359 
1360 //------------------------------------------------------------------------------
1361 /// The basic design of the NativeProcessLinux is built around two threads.
1362 ///
1363 /// One thread (@see SignalThread) simply blocks on a call to waitpid() looking
1364 /// for changes in the debugee state.  When a change is detected a
1365 /// ProcessMessage is sent to the associated ProcessLinux instance.  This thread
1366 /// "drives" state changes in the debugger.
1367 ///
1368 /// The second thread (@see OperationThread) is responsible for two things 1)
1369 /// launching or attaching to the inferior process, and then 2) servicing
1370 /// operations such as register reads/writes, stepping, etc.  See the comments
1371 /// on the Operation class for more info as to why this is needed.
1372 void
1373 NativeProcessLinux::LaunchInferior (
1374     Module *module,
1375     const char *argv[],
1376     const char *envp[],
1377     const std::string &stdin_path,
1378     const std::string &stdout_path,
1379     const std::string &stderr_path,
1380     const char *working_dir,
1381     const lldb_private::ProcessLaunchInfo &launch_info,
1382     lldb_private::Error &error)
1383 {
1384     if (module)
1385         m_arch = module->GetArchitecture ();
1386 
1387     SetState (eStateLaunching);
1388 
1389     std::unique_ptr<LaunchArgs> args(
1390         new LaunchArgs(
1391             this, module, argv, envp,
1392             stdin_path, stdout_path, stderr_path,
1393             working_dir, launch_info));
1394 
1395     sem_init (&m_operation_pending, 0, 0);
1396     sem_init (&m_operation_done, 0, 0);
1397 
1398     StartLaunchOpThread (args.get(), error);
1399     if (!error.Success ())
1400         return;
1401 
1402     error = StartCoordinatorThread ();
1403     if (!error.Success ())
1404         return;
1405 
1406 WAIT_AGAIN:
1407     // Wait for the operation thread to initialize.
1408     if (sem_wait(&args->m_semaphore))
1409     {
1410         if (errno == EINTR)
1411             goto WAIT_AGAIN;
1412         else
1413         {
1414             error.SetErrorToErrno();
1415             return;
1416         }
1417     }
1418 
1419     // Check that the launch was a success.
1420     if (!args->m_error.Success())
1421     {
1422         StopOpThread();
1423         StopCoordinatorThread ();
1424         error = args->m_error;
1425         return;
1426     }
1427 
1428     // Finally, start monitoring the child process for change in state.
1429     m_monitor_thread = Host::StartMonitoringChildProcess(
1430         NativeProcessLinux::MonitorCallback, this, GetID(), true);
1431     if (!m_monitor_thread.IsJoinable())
1432     {
1433         error.SetErrorToGenericError();
1434         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1435         return;
1436     }
1437 }
1438 
1439 void
1440 NativeProcessLinux::AttachToInferior (lldb::pid_t pid, lldb_private::Error &error)
1441 {
1442     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1443     if (log)
1444         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ")", __FUNCTION__, pid);
1445 
1446     // We can use the Host for everything except the ResolveExecutable portion.
1447     PlatformSP platform_sp = Platform::GetHostPlatform ();
1448     if (!platform_sp)
1449     {
1450         if (log)
1451             log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 "): no default platform set", __FUNCTION__, pid);
1452         error.SetErrorString ("no default platform available");
1453         return;
1454     }
1455 
1456     // Gather info about the process.
1457     ProcessInstanceInfo process_info;
1458     if (!platform_sp->GetProcessInfo (pid, process_info))
1459     {
1460         if (log)
1461             log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 "): failed to get process info", __FUNCTION__, pid);
1462         error.SetErrorString ("failed to get process info");
1463         return;
1464     }
1465 
1466     // Resolve the executable module
1467     ModuleSP exe_module_sp;
1468     FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths());
1469     ModuleSpec exe_module_spec(process_info.GetExecutableFile(), HostInfo::GetArchitecture());
1470     error = platform_sp->ResolveExecutable(exe_module_spec, exe_module_sp,
1471                                            executable_search_paths.GetSize() ? &executable_search_paths : NULL);
1472     if (!error.Success())
1473         return;
1474 
1475     // Set the architecture to the exe architecture.
1476     m_arch = exe_module_sp->GetArchitecture();
1477     if (log)
1478         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ") detected architecture %s", __FUNCTION__, pid, m_arch.GetArchitectureName ());
1479 
1480     m_pid = pid;
1481     SetState(eStateAttaching);
1482 
1483     sem_init (&m_operation_pending, 0, 0);
1484     sem_init (&m_operation_done, 0, 0);
1485 
1486     std::unique_ptr<AttachArgs> args (new AttachArgs (this, pid));
1487 
1488     StartAttachOpThread(args.get (), error);
1489     if (!error.Success ())
1490         return;
1491 
1492     error = StartCoordinatorThread ();
1493     if (!error.Success ())
1494         return;
1495 
1496 WAIT_AGAIN:
1497     // Wait for the operation thread to initialize.
1498     if (sem_wait (&args->m_semaphore))
1499     {
1500         if (errno == EINTR)
1501             goto WAIT_AGAIN;
1502         else
1503         {
1504             error.SetErrorToErrno ();
1505             return;
1506         }
1507     }
1508 
1509     // Check that the attach was a success.
1510     if (!args->m_error.Success ())
1511     {
1512         StopOpThread ();
1513         StopCoordinatorThread ();
1514         error = args->m_error;
1515         return;
1516     }
1517 
1518     // Finally, start monitoring the child process for change in state.
1519     m_monitor_thread = Host::StartMonitoringChildProcess (
1520         NativeProcessLinux::MonitorCallback, this, GetID (), true);
1521     if (!m_monitor_thread.IsJoinable())
1522     {
1523         error.SetErrorToGenericError ();
1524         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1525         return;
1526     }
1527 }
1528 
1529 NativeProcessLinux::~NativeProcessLinux()
1530 {
1531     StopMonitor();
1532 }
1533 
1534 //------------------------------------------------------------------------------
1535 // Thread setup and tear down.
1536 
1537 void
1538 NativeProcessLinux::StartLaunchOpThread(LaunchArgs *args, Error &error)
1539 {
1540     static const char *g_thread_name = "lldb.process.nativelinux.operation";
1541 
1542     if (m_operation_thread.IsJoinable())
1543         return;
1544 
1545     m_operation_thread = ThreadLauncher::LaunchThread(g_thread_name, LaunchOpThread, args, &error);
1546 }
1547 
1548 void *
1549 NativeProcessLinux::LaunchOpThread(void *arg)
1550 {
1551     LaunchArgs *args = static_cast<LaunchArgs*>(arg);
1552 
1553     if (!Launch(args)) {
1554         sem_post(&args->m_semaphore);
1555         return NULL;
1556     }
1557 
1558     ServeOperation(args);
1559     return NULL;
1560 }
1561 
1562 bool
1563 NativeProcessLinux::Launch(LaunchArgs *args)
1564 {
1565     assert (args && "null args");
1566     if (!args)
1567         return false;
1568 
1569     NativeProcessLinux *monitor = args->m_monitor;
1570     assert (monitor && "monitor is NULL");
1571     if (!monitor)
1572         return false;
1573 
1574     const char **argv = args->m_argv;
1575     const char **envp = args->m_envp;
1576     const char *working_dir = args->m_working_dir;
1577 
1578     lldb_utility::PseudoTerminal terminal;
1579     const size_t err_len = 1024;
1580     char err_str[err_len];
1581     lldb::pid_t pid;
1582     NativeThreadProtocolSP thread_sp;
1583 
1584     lldb::ThreadSP inferior;
1585 
1586     // Propagate the environment if one is not supplied.
1587     if (envp == NULL || envp[0] == NULL)
1588         envp = const_cast<const char **>(environ);
1589 
1590     if ((pid = terminal.Fork(err_str, err_len)) == static_cast<lldb::pid_t> (-1))
1591     {
1592         args->m_error.SetErrorToGenericError();
1593         args->m_error.SetErrorString("Process fork failed.");
1594         return false;
1595     }
1596 
1597     // Recognized child exit status codes.
1598     enum {
1599         ePtraceFailed = 1,
1600         eDupStdinFailed,
1601         eDupStdoutFailed,
1602         eDupStderrFailed,
1603         eChdirFailed,
1604         eExecFailed,
1605         eSetGidFailed
1606     };
1607 
1608     // Child process.
1609     if (pid == 0)
1610     {
1611         // FIXME consider opening a pipe between parent/child and have this forked child
1612         // send log info to parent re: launch status, in place of the log lines removed here.
1613 
1614         // Start tracing this child that is about to exec.
1615         if (PTRACE(PTRACE_TRACEME, 0, NULL, NULL, 0) < 0)
1616             exit(ePtraceFailed);
1617 
1618         // Do not inherit setgid powers.
1619         if (setgid(getgid()) != 0)
1620             exit(eSetGidFailed);
1621 
1622         // Attempt to have our own process group.
1623         if (setpgid(0, 0) != 0)
1624         {
1625             // FIXME log that this failed. This is common.
1626             // Don't allow this to prevent an inferior exec.
1627         }
1628 
1629         // Dup file descriptors if needed.
1630         if (!args->m_stdin_path.empty ())
1631             if (!DupDescriptor(args->m_stdin_path.c_str (), STDIN_FILENO, O_RDONLY))
1632                 exit(eDupStdinFailed);
1633 
1634         if (!args->m_stdout_path.empty ())
1635             if (!DupDescriptor(args->m_stdout_path.c_str (), STDOUT_FILENO, O_WRONLY | O_CREAT))
1636                 exit(eDupStdoutFailed);
1637 
1638         if (!args->m_stderr_path.empty ())
1639             if (!DupDescriptor(args->m_stderr_path.c_str (), STDERR_FILENO, O_WRONLY | O_CREAT))
1640                 exit(eDupStderrFailed);
1641 
1642         // Change working directory
1643         if (working_dir != NULL && working_dir[0])
1644           if (0 != ::chdir(working_dir))
1645               exit(eChdirFailed);
1646 
1647         // Disable ASLR if requested.
1648         if (args->m_launch_info.GetFlags ().Test (lldb::eLaunchFlagDisableASLR))
1649         {
1650             const int old_personality = personality (LLDB_PERSONALITY_GET_CURRENT_SETTINGS);
1651             if (old_personality == -1)
1652             {
1653                 // Can't retrieve Linux personality.  Cannot disable ASLR.
1654             }
1655             else
1656             {
1657                 const int new_personality = personality (ADDR_NO_RANDOMIZE | old_personality);
1658                 if (new_personality == -1)
1659                 {
1660                     // Disabling ASLR failed.
1661                 }
1662                 else
1663                 {
1664                     // Disabling ASLR succeeded.
1665                 }
1666             }
1667         }
1668 
1669         // Execute.  We should never return...
1670         execve(argv[0],
1671                const_cast<char *const *>(argv),
1672                const_cast<char *const *>(envp));
1673 
1674         // ...unless exec fails.  In which case we definitely need to end the child here.
1675         exit(eExecFailed);
1676     }
1677 
1678     //
1679     // This is the parent code here.
1680     //
1681     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1682 
1683     // Wait for the child process to trap on its call to execve.
1684     ::pid_t wpid;
1685     int status;
1686     if ((wpid = waitpid(pid, &status, 0)) < 0)
1687     {
1688         args->m_error.SetErrorToErrno();
1689 
1690         if (log)
1691             log->Printf ("NativeProcessLinux::%s waitpid for inferior failed with %s", __FUNCTION__, args->m_error.AsCString ());
1692 
1693         // Mark the inferior as invalid.
1694         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1695         monitor->SetState (StateType::eStateInvalid);
1696 
1697         return false;
1698     }
1699     else if (WIFEXITED(status))
1700     {
1701         // open, dup or execve likely failed for some reason.
1702         args->m_error.SetErrorToGenericError();
1703         switch (WEXITSTATUS(status))
1704         {
1705             case ePtraceFailed:
1706                 args->m_error.SetErrorString("Child ptrace failed.");
1707                 break;
1708             case eDupStdinFailed:
1709                 args->m_error.SetErrorString("Child open stdin failed.");
1710                 break;
1711             case eDupStdoutFailed:
1712                 args->m_error.SetErrorString("Child open stdout failed.");
1713                 break;
1714             case eDupStderrFailed:
1715                 args->m_error.SetErrorString("Child open stderr failed.");
1716                 break;
1717             case eChdirFailed:
1718                 args->m_error.SetErrorString("Child failed to set working directory.");
1719                 break;
1720             case eExecFailed:
1721                 args->m_error.SetErrorString("Child exec failed.");
1722                 break;
1723             case eSetGidFailed:
1724                 args->m_error.SetErrorString("Child setgid failed.");
1725                 break;
1726             default:
1727                 args->m_error.SetErrorString("Child returned unknown exit status.");
1728                 break;
1729         }
1730 
1731         if (log)
1732         {
1733             log->Printf ("NativeProcessLinux::%s inferior exited with status %d before issuing a STOP",
1734                     __FUNCTION__,
1735                     WEXITSTATUS(status));
1736         }
1737 
1738         // Mark the inferior as invalid.
1739         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1740         monitor->SetState (StateType::eStateInvalid);
1741 
1742         return false;
1743     }
1744     assert(WIFSTOPPED(status) && (wpid == static_cast< ::pid_t> (pid)) &&
1745            "Could not sync with inferior process.");
1746 
1747     if (log)
1748         log->Printf ("NativeProcessLinux::%s inferior started, now in stopped state", __FUNCTION__);
1749 
1750     if (!SetDefaultPtraceOpts(pid))
1751     {
1752         args->m_error.SetErrorToErrno();
1753         if (log)
1754             log->Printf ("NativeProcessLinux::%s inferior failed to set default ptrace options: %s",
1755                     __FUNCTION__,
1756                     args->m_error.AsCString ());
1757 
1758         // Mark the inferior as invalid.
1759         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1760         monitor->SetState (StateType::eStateInvalid);
1761 
1762         return false;
1763     }
1764 
1765     // Release the master terminal descriptor and pass it off to the
1766     // NativeProcessLinux instance.  Similarly stash the inferior pid.
1767     monitor->m_terminal_fd = terminal.ReleaseMasterFileDescriptor();
1768     monitor->m_pid = pid;
1769 
1770     // Set the terminal fd to be in non blocking mode (it simplifies the
1771     // implementation of ProcessLinux::GetSTDOUT to have a non-blocking
1772     // descriptor to read from).
1773     if (!EnsureFDFlags(monitor->m_terminal_fd, O_NONBLOCK, args->m_error))
1774     {
1775         if (log)
1776             log->Printf ("NativeProcessLinux::%s inferior EnsureFDFlags failed for ensuring terminal O_NONBLOCK setting: %s",
1777                     __FUNCTION__,
1778                     args->m_error.AsCString ());
1779 
1780         // Mark the inferior as invalid.
1781         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1782         monitor->SetState (StateType::eStateInvalid);
1783 
1784         return false;
1785     }
1786 
1787     if (log)
1788         log->Printf ("NativeProcessLinux::%s() adding pid = %" PRIu64, __FUNCTION__, pid);
1789 
1790     thread_sp = monitor->AddThread (pid);
1791     assert (thread_sp && "AddThread() returned a nullptr thread");
1792     monitor->NotifyThreadCreateStopped (pid);
1793     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1794 
1795     // Let our process instance know the thread has stopped.
1796     monitor->SetCurrentThreadID (thread_sp->GetID ());
1797     monitor->SetState (StateType::eStateStopped);
1798 
1799     if (log)
1800     {
1801         if (args->m_error.Success ())
1802         {
1803             log->Printf ("NativeProcessLinux::%s inferior launching succeeded", __FUNCTION__);
1804         }
1805         else
1806         {
1807             log->Printf ("NativeProcessLinux::%s inferior launching failed: %s",
1808                 __FUNCTION__,
1809                 args->m_error.AsCString ());
1810         }
1811     }
1812     return args->m_error.Success();
1813 }
1814 
1815 void
1816 NativeProcessLinux::StartAttachOpThread(AttachArgs *args, lldb_private::Error &error)
1817 {
1818     static const char *g_thread_name = "lldb.process.linux.operation";
1819 
1820     if (m_operation_thread.IsJoinable())
1821         return;
1822 
1823     m_operation_thread = ThreadLauncher::LaunchThread(g_thread_name, AttachOpThread, args, &error);
1824 }
1825 
1826 void *
1827 NativeProcessLinux::AttachOpThread(void *arg)
1828 {
1829     AttachArgs *args = static_cast<AttachArgs*>(arg);
1830 
1831     if (!Attach(args)) {
1832         sem_post(&args->m_semaphore);
1833         return nullptr;
1834     }
1835 
1836     ServeOperation(args);
1837     return nullptr;
1838 }
1839 
1840 bool
1841 NativeProcessLinux::Attach(AttachArgs *args)
1842 {
1843     lldb::pid_t pid = args->m_pid;
1844 
1845     NativeProcessLinux *monitor = args->m_monitor;
1846     lldb::ThreadSP inferior;
1847     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1848 
1849     // Use a map to keep track of the threads which we have attached/need to attach.
1850     Host::TidMap tids_to_attach;
1851     if (pid <= 1)
1852     {
1853         args->m_error.SetErrorToGenericError();
1854         args->m_error.SetErrorString("Attaching to process 1 is not allowed.");
1855         goto FINISH;
1856     }
1857 
1858     while (Host::FindProcessThreads(pid, tids_to_attach))
1859     {
1860         for (Host::TidMap::iterator it = tids_to_attach.begin();
1861              it != tids_to_attach.end();)
1862         {
1863             if (it->second == false)
1864             {
1865                 lldb::tid_t tid = it->first;
1866 
1867                 // Attach to the requested process.
1868                 // An attach will cause the thread to stop with a SIGSTOP.
1869                 if (PTRACE(PTRACE_ATTACH, tid, NULL, NULL, 0) < 0)
1870                 {
1871                     // No such thread. The thread may have exited.
1872                     // More error handling may be needed.
1873                     if (errno == ESRCH)
1874                     {
1875                         it = tids_to_attach.erase(it);
1876                         continue;
1877                     }
1878                     else
1879                     {
1880                         args->m_error.SetErrorToErrno();
1881                         goto FINISH;
1882                     }
1883                 }
1884 
1885                 int status;
1886                 // Need to use __WALL otherwise we receive an error with errno=ECHLD
1887                 // At this point we should have a thread stopped if waitpid succeeds.
1888                 if ((status = waitpid(tid, NULL, __WALL)) < 0)
1889                 {
1890                     // No such thread. The thread may have exited.
1891                     // More error handling may be needed.
1892                     if (errno == ESRCH)
1893                     {
1894                         it = tids_to_attach.erase(it);
1895                         continue;
1896                     }
1897                     else
1898                     {
1899                         args->m_error.SetErrorToErrno();
1900                         goto FINISH;
1901                     }
1902                 }
1903 
1904                 if (!SetDefaultPtraceOpts(tid))
1905                 {
1906                     args->m_error.SetErrorToErrno();
1907                     goto FINISH;
1908                 }
1909 
1910 
1911                 if (log)
1912                     log->Printf ("NativeProcessLinux::%s() adding tid = %" PRIu64, __FUNCTION__, tid);
1913 
1914                 it->second = true;
1915 
1916                 // Create the thread, mark it as stopped.
1917                 NativeThreadProtocolSP thread_sp (monitor->AddThread (static_cast<lldb::tid_t> (tid)));
1918                 assert (thread_sp && "AddThread() returned a nullptr");
1919 
1920                 // This will notify this is a new thread and tell the system it is stopped.
1921                 monitor->NotifyThreadCreateStopped (tid);
1922                 reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1923                 monitor->SetCurrentThreadID (thread_sp->GetID ());
1924             }
1925 
1926             // move the loop forward
1927             ++it;
1928         }
1929     }
1930 
1931     if (tids_to_attach.size() > 0)
1932     {
1933         monitor->m_pid = pid;
1934         // Let our process instance know the thread has stopped.
1935         monitor->SetState (StateType::eStateStopped);
1936     }
1937     else
1938     {
1939         args->m_error.SetErrorToGenericError();
1940         args->m_error.SetErrorString("No such process.");
1941     }
1942 
1943  FINISH:
1944     return args->m_error.Success();
1945 }
1946 
1947 bool
1948 NativeProcessLinux::SetDefaultPtraceOpts(lldb::pid_t pid)
1949 {
1950     long ptrace_opts = 0;
1951 
1952     // Have the child raise an event on exit.  This is used to keep the child in
1953     // limbo until it is destroyed.
1954     ptrace_opts |= PTRACE_O_TRACEEXIT;
1955 
1956     // Have the tracer trace threads which spawn in the inferior process.
1957     // TODO: if we want to support tracing the inferiors' child, add the
1958     // appropriate ptrace flags here (PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)
1959     ptrace_opts |= PTRACE_O_TRACECLONE;
1960 
1961     // Have the tracer notify us before execve returns
1962     // (needed to disable legacy SIGTRAP generation)
1963     ptrace_opts |= PTRACE_O_TRACEEXEC;
1964 
1965     return PTRACE(PTRACE_SETOPTIONS, pid, NULL, (void*)ptrace_opts, 0) >= 0;
1966 }
1967 
1968 static ExitType convert_pid_status_to_exit_type (int status)
1969 {
1970     if (WIFEXITED (status))
1971         return ExitType::eExitTypeExit;
1972     else if (WIFSIGNALED (status))
1973         return ExitType::eExitTypeSignal;
1974     else if (WIFSTOPPED (status))
1975         return ExitType::eExitTypeStop;
1976     else
1977     {
1978         // We don't know what this is.
1979         return ExitType::eExitTypeInvalid;
1980     }
1981 }
1982 
1983 static int convert_pid_status_to_return_code (int status)
1984 {
1985     if (WIFEXITED (status))
1986         return WEXITSTATUS (status);
1987     else if (WIFSIGNALED (status))
1988         return WTERMSIG (status);
1989     else if (WIFSTOPPED (status))
1990         return WSTOPSIG (status);
1991     else
1992     {
1993         // We don't know what this is.
1994         return ExitType::eExitTypeInvalid;
1995     }
1996 }
1997 
1998 // Main process monitoring waitpid-loop handler.
1999 bool
2000 NativeProcessLinux::MonitorCallback(void *callback_baton,
2001                                 lldb::pid_t pid,
2002                                 bool exited,
2003                                 int signal,
2004                                 int status)
2005 {
2006     Log *log (GetLogIfAnyCategoriesSet (LIBLLDB_LOG_PROCESS));
2007 
2008     NativeProcessLinux *const process = static_cast<NativeProcessLinux*>(callback_baton);
2009     assert (process && "process is null");
2010     if (!process)
2011     {
2012         if (log)
2013             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " callback_baton was null, can't determine process to use", __FUNCTION__, pid);
2014         return true;
2015     }
2016 
2017     // Certain activities differ based on whether the pid is the tid of the main thread.
2018     const bool is_main_thread = (pid == process->GetID ());
2019 
2020     // Assume we keep monitoring by default.
2021     bool stop_monitoring = false;
2022 
2023     // Handle when the thread exits.
2024     if (exited)
2025     {
2026         if (log)
2027             log->Printf ("NativeProcessLinux::%s() got exit signal, tid = %"  PRIu64 " (%s main thread)", __FUNCTION__, pid, is_main_thread ? "is" : "is not");
2028 
2029         // This is a thread that exited.  Ensure we're not tracking it anymore.
2030         const bool thread_found = process->StopTrackingThread (pid);
2031 
2032         // Make sure the thread state coordinator knows about this.
2033         process->NotifyThreadDeath (pid);
2034 
2035         if (is_main_thread)
2036         {
2037             // We only set the exit status and notify the delegate if we haven't already set the process
2038             // state to an exited state.  We normally should have received a SIGTRAP | (PTRACE_EVENT_EXIT << 8)
2039             // for the main thread.
2040             const bool already_notified = (process->GetState() == StateType::eStateExited) || (process->GetState () == StateType::eStateCrashed);
2041             if (!already_notified)
2042             {
2043                 if (log)
2044                     log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " handling main thread exit (%s), expected exit state already set but state was %s instead, setting exit state now", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found", StateAsCString (process->GetState ()));
2045                 // The main thread exited.  We're done monitoring.  Report to delegate.
2046                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
2047 
2048                 // Notify delegate that our process has exited.
2049                 process->SetState (StateType::eStateExited, true);
2050             }
2051             else
2052             {
2053                 if (log)
2054                     log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " main thread now exited (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
2055             }
2056             return true;
2057         }
2058         else
2059         {
2060             // Do we want to report to the delegate in this case?  I think not.  If this was an orderly
2061             // thread exit, we would already have received the SIGTRAP | (PTRACE_EVENT_EXIT << 8) signal,
2062             // and we would have done an all-stop then.
2063             if (log)
2064                 log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " handling non-main thread exit (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
2065 
2066             // Not the main thread, we keep going.
2067             return false;
2068         }
2069     }
2070 
2071     // Get details on the signal raised.
2072     siginfo_t info;
2073     int ptrace_err = 0;
2074 
2075     if (process->GetSignalInfo (pid, &info, ptrace_err))
2076     {
2077         // We have retrieved the signal info.  Dispatch appropriately.
2078         if (info.si_signo == SIGTRAP)
2079             process->MonitorSIGTRAP(&info, pid);
2080         else
2081             process->MonitorSignal(&info, pid, exited);
2082 
2083         stop_monitoring = false;
2084     }
2085     else
2086     {
2087         if (ptrace_err == EINVAL)
2088         {
2089             // This is a group stop reception for this tid.
2090             if (log)
2091                 log->Printf ("NativeThreadLinux::%s received a group stop for pid %" PRIu64 " tid %" PRIu64, __FUNCTION__, process->GetID (), pid);
2092             process->NotifyThreadStop (pid);
2093         }
2094         else
2095         {
2096             // ptrace(GETSIGINFO) failed (but not due to group-stop).
2097 
2098             // A return value of ESRCH means the thread/process is no longer on the system,
2099             // so it was killed somehow outside of our control.  Either way, we can't do anything
2100             // with it anymore.
2101 
2102             // We stop monitoring if it was the main thread.
2103             stop_monitoring = is_main_thread;
2104 
2105             // Stop tracking the metadata for the thread since it's entirely off the system now.
2106             const bool thread_found = process->StopTrackingThread (pid);
2107 
2108             // Make sure the thread state coordinator knows about this.
2109             process->NotifyThreadDeath (pid);
2110 
2111             if (log)
2112                 log->Printf ("NativeProcessLinux::%s GetSignalInfo failed: %s, tid = %" PRIu64 ", signal = %d, status = %d (%s, %s, %s)",
2113                              __FUNCTION__, strerror(ptrace_err), pid, signal, status, ptrace_err == ESRCH ? "thread/process killed" : "unknown reason", is_main_thread ? "is main thread" : "is not main thread", thread_found ? "thread metadata removed" : "thread metadata not found");
2114 
2115             if (is_main_thread)
2116             {
2117                 // Notify the delegate - our process is not available but appears to have been killed outside
2118                 // our control.  Is eStateExited the right exit state in this case?
2119                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
2120                 process->SetState (StateType::eStateExited, true);
2121             }
2122             else
2123             {
2124                 // This thread was pulled out from underneath us.  Anything to do here? Do we want to do an all stop?
2125                 if (log)
2126                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " non-main thread exit occurred, didn't tell delegate anything since thread disappeared out from underneath us", __FUNCTION__, process->GetID (), pid);
2127             }
2128         }
2129     }
2130 
2131     return stop_monitoring;
2132 }
2133 
2134 void
2135 NativeProcessLinux::MonitorSIGTRAP(const siginfo_t *info, lldb::pid_t pid)
2136 {
2137     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2138     const bool is_main_thread = (pid == GetID ());
2139 
2140     assert(info && info->si_signo == SIGTRAP && "Unexpected child signal!");
2141     if (!info)
2142         return;
2143 
2144     // See if we can find a thread for this signal.
2145     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2146     if (!thread_sp)
2147     {
2148         if (log)
2149             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2150     }
2151 
2152     switch (info->si_code)
2153     {
2154     // TODO: these two cases are required if we want to support tracing of the inferiors' children.  We'd need this to debug a monitor.
2155     // case (SIGTRAP | (PTRACE_EVENT_FORK << 8)):
2156     // case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):
2157 
2158     case (SIGTRAP | (PTRACE_EVENT_CLONE << 8)):
2159     {
2160         lldb::tid_t tid = LLDB_INVALID_THREAD_ID;
2161 
2162         // The main thread is stopped here.
2163         if (thread_sp)
2164             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2165         NotifyThreadStop (pid);
2166 
2167         unsigned long event_message = 0;
2168         if (GetEventMessage (pid, &event_message))
2169         {
2170             tid = static_cast<lldb::tid_t> (event_message);
2171             if (log)
2172                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " received thread creation event for tid %" PRIu64, __FUNCTION__, pid, tid);
2173 
2174             // If we don't track the thread yet: create it, mark as stopped.
2175             // If we do track it, this is the wait we needed.  Now resume the new thread.
2176             // In all cases, resume the current (i.e. main process) thread.
2177             bool created_now = false;
2178             NativeThreadProtocolSP new_thread_sp = GetOrCreateThread (tid, created_now);
2179             assert (new_thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2180 
2181             // If the thread was already tracked, it means the created thread already received its SI_USER notification of creation.
2182             if (!created_now)
2183             {
2184                 // We can now resume the newly created thread since it is fully created.
2185                 NotifyThreadCreateStopped (tid);
2186                 m_coordinator_up->RequestThreadResume (tid,
2187                                                        [=](lldb::tid_t tid_to_resume)
2188                                                        {
2189                                                            reinterpret_cast<NativeThreadLinux*> (new_thread_sp.get ())->SetRunning ();
2190                                                            Resume (tid_to_resume, LLDB_INVALID_SIGNAL_NUMBER);
2191                                                        },
2192                                                        CoordinatorErrorHandler);
2193             }
2194             else
2195             {
2196                 // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2197                 // this thread is ready to go.
2198                 reinterpret_cast<NativeThreadLinux*> (new_thread_sp.get ())->SetLaunching ();
2199             }
2200         }
2201         else
2202         {
2203             if (log)
2204                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " received thread creation event but GetEventMessage failed so we don't know the new tid", __FUNCTION__, pid);
2205         }
2206 
2207         // In all cases, we can resume the main thread here.
2208         m_coordinator_up->RequestThreadResume (pid,
2209                                                [=](lldb::tid_t tid_to_resume)
2210                                                {
2211                                                    reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2212                                                    Resume (tid_to_resume, LLDB_INVALID_SIGNAL_NUMBER);
2213                                                },
2214                                                CoordinatorErrorHandler);
2215 
2216         break;
2217     }
2218 
2219     case (SIGTRAP | (PTRACE_EVENT_EXEC << 8)):
2220     {
2221         NativeThreadProtocolSP main_thread_sp;
2222         if (log)
2223             log->Printf ("NativeProcessLinux::%s() received exec event, code = %d", __FUNCTION__, info->si_code ^ SIGTRAP);
2224 
2225         // The thread state coordinator needs to reset due to the exec.
2226         m_coordinator_up->ResetForExec ();
2227 
2228         // Remove all but the main thread here.  Linux fork creates a new process which only copies the main thread.  Mutexes are in undefined state.
2229         {
2230             Mutex::Locker locker (m_threads_mutex);
2231 
2232             if (log)
2233                 log->Printf ("NativeProcessLinux::%s exec received, stop tracking all but main thread", __FUNCTION__);
2234 
2235             for (auto thread_sp : m_threads)
2236             {
2237                 const bool is_main_thread = thread_sp && thread_sp->GetID () == GetID ();
2238                 if (is_main_thread)
2239                 {
2240                     main_thread_sp = thread_sp;
2241                     if (log)
2242                         log->Printf ("NativeProcessLinux::%s found main thread with tid %" PRIu64 ", keeping", __FUNCTION__, main_thread_sp->GetID ());
2243                 }
2244                 else
2245                 {
2246                     // Tell thread coordinator this thread is dead.
2247                     if (log)
2248                         log->Printf ("NativeProcessLinux::%s discarding non-main-thread tid %" PRIu64 " due to exec", __FUNCTION__, thread_sp->GetID ());
2249                 }
2250             }
2251 
2252             m_threads.clear ();
2253 
2254             if (main_thread_sp)
2255             {
2256                 m_threads.push_back (main_thread_sp);
2257                 SetCurrentThreadID (main_thread_sp->GetID ());
2258                 reinterpret_cast<NativeThreadLinux*>(main_thread_sp.get())->SetStoppedByExec ();
2259             }
2260             else
2261             {
2262                 SetCurrentThreadID (LLDB_INVALID_THREAD_ID);
2263                 if (log)
2264                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 "no main thread found, discarded all threads, we're in a no-thread state!", __FUNCTION__, GetID ());
2265             }
2266         }
2267 
2268         // Tell coordinator about about the "new" (since exec) stopped main thread.
2269         const lldb::tid_t main_thread_tid = GetID ();
2270         NotifyThreadCreateStopped (main_thread_tid);
2271 
2272         // NOTE: ideally these next statements would execute at the same time as the coordinator thread create was executed.
2273         // Consider a handler that can execute when that happens.
2274         // Let our delegate know we have just exec'd.
2275         NotifyDidExec ();
2276 
2277         // If we have a main thread, indicate we are stopped.
2278         assert (main_thread_sp && "exec called during ptraced process but no main thread metadata tracked");
2279 
2280         // Let the process know we're stopped.
2281         SetState (StateType::eStateStopped);
2282 
2283         break;
2284     }
2285 
2286     case (SIGTRAP | (PTRACE_EVENT_EXIT << 8)):
2287     {
2288         // The inferior process or one of its threads is about to exit.
2289 
2290         // This thread is currently stopped.  It's not actually dead yet, just about to be.
2291         NotifyThreadStop (pid);
2292 
2293         unsigned long data = 0;
2294         if (!GetEventMessage(pid, &data))
2295             data = -1;
2296 
2297         if (log)
2298         {
2299             log->Printf ("NativeProcessLinux::%s() received PTRACE_EVENT_EXIT, data = %lx (WIFEXITED=%s,WIFSIGNALED=%s), pid = %" PRIu64 " (%s)",
2300                          __FUNCTION__,
2301                          data, WIFEXITED (data) ? "true" : "false", WIFSIGNALED (data) ? "true" : "false",
2302                          pid,
2303                     is_main_thread ? "is main thread" : "not main thread");
2304         }
2305 
2306         // We'll set the thread to exited later...
2307 //        if (thread_sp)
2308 //            reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetExited ();
2309 //        else
2310 //        {
2311 //            if (log)
2312 //                log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " failed to retrieve thread for tid %" PRIu64", cannot set thread state", __FUNCTION__, GetID (), pid);
2313 //        }
2314 
2315         // FIXME: review if this is the spot, or the follow up, which tells us the real exit code.
2316         // If it's this one, we need to track it or set it here.  Setting it here is not really in the
2317         // right time flow though unless we skip the follow up.
2318         if (is_main_thread)
2319         {
2320             SetExitStatus (convert_pid_status_to_exit_type (data), convert_pid_status_to_return_code (data), nullptr, true);
2321         }
2322 
2323         m_coordinator_up->RequestThreadResume (pid,
2324                                                [=](lldb::tid_t tid_to_resume)
2325                                                {
2326                                                    reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2327                                                    Resume (tid_to_resume, LLDB_INVALID_SIGNAL_NUMBER);
2328                                                },
2329                                                CoordinatorErrorHandler);
2330 
2331         break;
2332     }
2333 
2334     case 0:
2335     case TRAP_TRACE:
2336         // We receive this on single stepping.
2337         if (log)
2338             log->Printf ("NativeProcessLinux::%s() received trace event, pid = %" PRIu64 " (single stepping)", __FUNCTION__, pid);
2339 
2340         // This thread is currently stopped.
2341         NotifyThreadStop (pid);
2342 
2343         // Here we don't have to request the rest of the threads to stop or request a deferred stop.
2344         // This would have already happened at the time the Resume() with step operation was signaled.
2345         // At this point, we just need to say we stopped, and the deferred notifcation will fire off
2346         // once all running threads have checked in as stopped.
2347         break;
2348 
2349     case SI_KERNEL:
2350     case TRAP_BRKPT:
2351         if (log)
2352             log->Printf ("NativeProcessLinux::%s() received breakpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2353 
2354         // This thread is currently stopped.
2355         NotifyThreadStop (pid);
2356 
2357         // Mark the thread as stopped at breakpoint.
2358         if (thread_sp)
2359         {
2360             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2361             Error error = FixupBreakpointPCAsNeeded (thread_sp);
2362             if (error.Fail ())
2363             {
2364                 if (log)
2365                     log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " fixup: %s", __FUNCTION__, pid, error.AsCString ());
2366             }
2367         }
2368         else
2369         {
2370             if (log)
2371                 log->Printf ("NativeProcessLinux::%s()  pid = %" PRIu64 ": warning, cannot process software breakpoint since no thread metadata", __FUNCTION__, pid);
2372         }
2373 
2374 
2375         // We need to tell all other running threads before we notify the delegate about this stop.
2376         CallAfterRunningThreadsStop (pid,
2377                                      [=](lldb::tid_t deferred_notification_tid)
2378                                      {
2379                                          SetCurrentThreadID (deferred_notification_tid);
2380                                          // Tell the process we have a stop (from software breakpoint).
2381                                          SetState (StateType::eStateStopped, true);
2382                                      });
2383         break;
2384 
2385     case TRAP_HWBKPT:
2386         if (log)
2387             log->Printf ("NativeProcessLinux::%s() received watchpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2388 
2389         // This thread is currently stopped.
2390         NotifyThreadStop (pid);
2391 
2392         // Mark the thread as stopped at watchpoint.
2393         // The address is at (lldb::addr_t)info->si_addr if we need it.
2394         if (thread_sp)
2395             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2396         else
2397         {
2398             if (log)
2399                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ": warning, cannot process hardware breakpoint since no thread metadata", __FUNCTION__, GetID (), pid);
2400         }
2401 
2402         // We need to tell all other running threads before we notify the delegate about this stop.
2403         CallAfterRunningThreadsStop (pid,
2404                                      [=](lldb::tid_t deferred_notification_tid)
2405                                      {
2406                                          SetCurrentThreadID (deferred_notification_tid);
2407                                          // Tell the process we have a stop (from hardware breakpoint).
2408                                          SetState (StateType::eStateStopped, true);
2409                                      });
2410         break;
2411 
2412     case SIGTRAP:
2413     case (SIGTRAP | 0x80):
2414         if (log)
2415             log->Printf ("NativeProcessLinux::%s() received unknown SIGTRAP system call stop event, pid %" PRIu64 "tid %" PRIu64 ", resuming", __FUNCTION__, GetID (), pid);
2416 
2417         // This thread is currently stopped.
2418         NotifyThreadStop (pid);
2419         if (thread_sp)
2420             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2421 
2422 
2423         // Ignore these signals until we know more about them.
2424         m_coordinator_up->RequestThreadResume (pid,
2425                                                [=](lldb::tid_t tid_to_resume)
2426                                                {
2427                                                    reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2428                                                    Resume (tid_to_resume, LLDB_INVALID_SIGNAL_NUMBER);
2429                                                },
2430                                                CoordinatorErrorHandler);
2431         break;
2432 
2433     default:
2434         assert(false && "Unexpected SIGTRAP code!");
2435         if (log)
2436             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 "tid %" PRIu64 " received unhandled SIGTRAP code: 0x%" PRIx64, __FUNCTION__, GetID (), pid, static_cast<uint64_t> (SIGTRAP | (PTRACE_EVENT_CLONE << 8)));
2437         break;
2438 
2439     }
2440 }
2441 
2442 void
2443 NativeProcessLinux::MonitorSignal(const siginfo_t *info, lldb::pid_t pid, bool exited)
2444 {
2445     assert (info && "null info");
2446     if (!info)
2447         return;
2448 
2449     const int signo = info->si_signo;
2450     const bool is_from_llgs = info->si_pid == getpid ();
2451 
2452     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2453 
2454     // POSIX says that process behaviour is undefined after it ignores a SIGFPE,
2455     // SIGILL, SIGSEGV, or SIGBUS *unless* that signal was generated by a
2456     // kill(2) or raise(3).  Similarly for tgkill(2) on Linux.
2457     //
2458     // IOW, user generated signals never generate what we consider to be a
2459     // "crash".
2460     //
2461     // Similarly, ACK signals generated by this monitor.
2462 
2463     // See if we can find a thread for this signal.
2464     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2465     if (!thread_sp)
2466     {
2467         if (log)
2468             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2469     }
2470 
2471     // Handle the signal.
2472     if (info->si_code == SI_TKILL || info->si_code == SI_USER)
2473     {
2474         if (log)
2475             log->Printf ("NativeProcessLinux::%s() received signal %s (%d) with code %s, (siginfo pid = %d (%s), waitpid pid = %" PRIu64 ")",
2476                             __FUNCTION__,
2477                             GetUnixSignals ().GetSignalAsCString (signo),
2478                             signo,
2479                             (info->si_code == SI_TKILL ? "SI_TKILL" : "SI_USER"),
2480                             info->si_pid,
2481                             is_from_llgs ? "from llgs" : "not from llgs",
2482                             pid);
2483     }
2484 
2485     // Check for new thread notification.
2486     if ((info->si_pid == 0) && (info->si_code == SI_USER))
2487     {
2488         // A new thread creation is being signaled.  This is one of two parts that come in
2489         // a non-deterministic order.  pid is the thread id.
2490         if (log)
2491             log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": new thread notification",
2492                      __FUNCTION__, GetID (), pid);
2493 
2494         // Did we already create the thread?
2495         bool created_now = false;
2496         thread_sp = GetOrCreateThread (pid, created_now);
2497         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2498 
2499         // If the thread was already tracked, it means the main thread already received its SIGTRAP for the create.
2500         if (!created_now)
2501         {
2502             // We can now resume the newly created thread since it is fully created.
2503             NotifyThreadCreateStopped (pid);
2504             m_coordinator_up->RequestThreadResume (pid,
2505                                                    [=](lldb::tid_t tid_to_resume)
2506                                                    {
2507                                                        reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2508                                                        Resume (tid_to_resume, LLDB_INVALID_SIGNAL_NUMBER);
2509                                                    },
2510                                                    CoordinatorErrorHandler);
2511         }
2512         else
2513         {
2514             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2515             // this thread is ready to go.
2516             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2517         }
2518 
2519         // Done handling.
2520         return;
2521     }
2522 
2523     // Check for thread stop notification.
2524     if (is_from_llgs && (info->si_code == SI_TKILL) && (signo == SIGSTOP))
2525     {
2526         // This is a tgkill()-based stop.
2527         if (thread_sp)
2528         {
2529             if (log)
2530                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ", thread stopped",
2531                              __FUNCTION__,
2532                              GetID (),
2533                              pid);
2534 
2535             // An inferior thread just stopped, but was not the primary cause of the process stop.
2536             // Instead, something else (like a breakpoint or step) caused the stop.  Mark the
2537             // stop signal as 0 to let lldb know this isn't the important stop.
2538             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (0);
2539             SetCurrentThreadID (thread_sp->GetID ());
2540 
2541             // Tell the thread state coordinator about the stop.
2542             NotifyThreadStop (thread_sp->GetID ());
2543         }
2544 
2545         // Done handling.
2546         return;
2547     }
2548 
2549     if (log)
2550         log->Printf ("NativeProcessLinux::%s() received signal %s", __FUNCTION__, GetUnixSignals ().GetSignalAsCString (signo));
2551 
2552     switch (signo)
2553     {
2554     case SIGSEGV:
2555     case SIGABRT:
2556     case SIGILL:
2557     case SIGFPE:
2558     case SIGBUS:
2559         {
2560             // This thread is stopped.
2561             NotifyThreadStop (pid);
2562 
2563             // lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2564 
2565             // This is just a pre-signal-delivery notification of the incoming signal.
2566             if (thread_sp)
2567                 reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2568 
2569             // We can get more details on the exact nature of the crash here.
2570             // ProcessMessage::CrashReason reason = GetCrashReasonForSIGSEGV(info);
2571             if (!exited)
2572             {
2573                 // Send a stop to the debugger after we get all other threads to stop.
2574                 CallAfterRunningThreadsStop (pid,
2575                                              [=] (lldb::tid_t signaling_tid)
2576                                              {
2577                                                  SetCurrentThreadID (signaling_tid);
2578                                                  SetState (StateType::eStateStopped, true);
2579                                              });
2580             }
2581             else
2582             {
2583                 // FIXME the process might die right after this - might not ever get stops on any other threads.
2584                 // Send a stop to the debugger after we get all other threads to stop.
2585                 CallAfterRunningThreadsStop (pid,
2586                                              [=] (lldb::tid_t signaling_tid)
2587                                              {
2588                                                  SetCurrentThreadID (signaling_tid);
2589                                                  SetState (StateType::eStateCrashed, true);
2590                                              });
2591             }
2592         }
2593         break;
2594 
2595     case SIGSTOP:
2596         {
2597             // This thread is stopped.
2598             NotifyThreadStop (pid);
2599 
2600             if (log)
2601             {
2602                 if (is_from_llgs)
2603                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " received SIGSTOP from llgs, most likely an interrupt", __FUNCTION__, GetID (), pid);
2604                 else
2605                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " received SIGSTOP from outside of debugger", __FUNCTION__, GetID (), pid);
2606             }
2607 
2608             // Resume this thread to get the group-stop mechanism to fire off the true group stops.
2609             // This thread will get stopped again as part of the group-stop completion.
2610             m_coordinator_up->RequestThreadResume (pid,
2611                                                    [=](lldb::tid_t tid_to_resume)
2612                                                    {
2613                                                        reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2614                                                        // Pass this signal number on to the inferior to handle.
2615                                                        Resume (tid_to_resume, signo);
2616                                                    },
2617                                                    CoordinatorErrorHandler);
2618 
2619             // And now we want to signal that we received a SIGSTOP on this thread
2620             // as soon as all running threads stop (i.e. the group stop sequence completes).
2621             CallAfterRunningThreadsStop (pid,
2622                                          [=] (lldb::tid_t signaling_tid)
2623                                          {
2624                                              SetCurrentThreadID (signaling_tid);
2625                                              SetState (StateType::eStateStopped, true);
2626                                          });
2627             break;
2628         }
2629 
2630     default:
2631         {
2632             // This thread is stopped.
2633             NotifyThreadStop (pid);
2634 
2635             if (log)
2636                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " resuming thread with signal %s (%d)", __FUNCTION__, GetID (), pid, GetUnixSignals().GetSignalAsCString (signo), signo);
2637 
2638             // Pass the signal on to the inferior.
2639             m_coordinator_up->RequestThreadResume (pid,
2640                                                    [=](lldb::tid_t tid_to_resume)
2641                                                    {
2642                                                        reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2643                                                        // Pass this signal number on to the inferior to handle.
2644                                                        Resume (tid_to_resume, signo);
2645                                                    },
2646                                                    CoordinatorErrorHandler);
2647         }
2648         break;
2649     }
2650 }
2651 
2652 Error
2653 NativeProcessLinux::Resume (const ResumeActionList &resume_actions)
2654 {
2655     Error error;
2656 
2657     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_THREAD));
2658     if (log)
2659         log->Printf ("NativeProcessLinux::%s called: pid %" PRIu64, __FUNCTION__, GetID ());
2660 
2661     lldb::tid_t deferred_signal_tid = LLDB_INVALID_THREAD_ID;
2662     lldb::tid_t deferred_signal_skip_tid = LLDB_INVALID_THREAD_ID;
2663     int deferred_signo = 0;
2664     NativeThreadProtocolSP deferred_signal_thread_sp;
2665     int resume_count = 0;
2666 
2667 
2668     // std::vector<NativeThreadProtocolSP> new_stop_threads;
2669 
2670     // Scope for threads mutex.
2671     {
2672         Mutex::Locker locker (m_threads_mutex);
2673         for (auto thread_sp : m_threads)
2674         {
2675             assert (thread_sp && "thread list should not contain NULL threads");
2676 
2677             const ResumeAction *const action = resume_actions.GetActionForThread (thread_sp->GetID (), true);
2678             assert (action && "NULL ResumeAction returned for thread during Resume ()");
2679 
2680             if (log)
2681             {
2682                 log->Printf ("NativeProcessLinux::%s processing resume action state %s for pid %" PRIu64 " tid %" PRIu64,
2683                         __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2684             }
2685 
2686             switch (action->state)
2687             {
2688             case eStateRunning:
2689             {
2690                 // Run the thread, possibly feeding it the signal.
2691                 const int signo = action->signal;
2692                 m_coordinator_up->RequestThreadResume (thread_sp->GetID (),
2693                                                        [=](lldb::tid_t tid_to_resume)
2694                                                        {
2695                                                            reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2696                                                            // Pass this signal number on to the inferior to handle.
2697                                                            Resume (tid_to_resume, (signo > 0) ? signo : LLDB_INVALID_SIGNAL_NUMBER);
2698                                                        },
2699                                                        CoordinatorErrorHandler);
2700                 ++resume_count;
2701                 break;
2702             }
2703 
2704             case eStateStepping:
2705             {
2706                 // Request the step.
2707                 const int signo = action->signal;
2708                 m_coordinator_up->RequestThreadResume (thread_sp->GetID (),
2709                                                        [=](lldb::tid_t tid_to_step)
2710                                                        {
2711                                                            reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStepping ();
2712                                                            auto step_result = SingleStep (tid_to_step,(signo > 0) ? signo : LLDB_INVALID_SIGNAL_NUMBER);
2713                                                            assert (step_result && "SingleStep() failed");
2714                                                        },
2715                                                        CoordinatorErrorHandler);
2716 
2717                 // The deferred signal tid is the stepping tid.
2718                 // This assumes there is only one stepping tid, or the last stepping tid is a fine choice.
2719                 deferred_signal_tid = thread_sp->GetID ();
2720                 deferred_signal_thread_sp = thread_sp;
2721 
2722                 // Don't send a stop request to this thread.  The thread resume request
2723                 // above will actually run the step thread, and it will finish the step
2724                 // by sending a SIGTRAP with the appropriate bits set.  So, the deferred
2725                 // signal call that happens at the end of the loop below needs to let
2726                 // the pending signal handling to *not* send a stop for this thread here
2727                 // since the start/stop step functionality will end up with a stop state.
2728                 // Otherwise, this stepping thread will get sent an erroneous tgkill for
2729                 // with a SIGSTOP signal.
2730                 deferred_signal_skip_tid = thread_sp->GetID ();
2731 
2732                 // And the stop signal we should apply for it is a SIGTRAP.
2733                 deferred_signo = SIGTRAP;
2734                 break;
2735             }
2736 
2737             case eStateSuspended:
2738             case eStateStopped:
2739                 // if we haven't chosen a deferred signal tid yet, use this one.
2740                 if (deferred_signal_tid == LLDB_INVALID_THREAD_ID)
2741                 {
2742                     deferred_signal_tid = thread_sp->GetID ();
2743                     deferred_signal_thread_sp = thread_sp;
2744                     deferred_signo = SIGSTOP;
2745                 }
2746                 break;
2747 
2748             default:
2749                 return Error ("NativeProcessLinux::%s (): unexpected state %s specified for pid %" PRIu64 ", tid %" PRIu64,
2750                         __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2751             }
2752         }
2753     }
2754 
2755     // If we resumed anything, this command was about starting a stopped thread,
2756     // not about stopping something that we should trigger later.
2757     if (resume_count > 0)
2758         return error;
2759 
2760     // If we had any thread stopping, then do a deferred notification of the chosen stop thread id and signal
2761     // after all other running threads have stopped.
2762     if (deferred_signal_tid != LLDB_INVALID_THREAD_ID)
2763     {
2764         CallAfterRunningThreadsStopWithSkipTID (deferred_signal_tid,
2765                                                 deferred_signal_skip_tid,
2766                                      [=](lldb::tid_t deferred_notification_tid)
2767                                      {
2768                                          // Set the signal thread to the current thread.
2769                                          SetCurrentThreadID (deferred_notification_tid);
2770 
2771                                          // Set the thread state as stopped by the deferred signo.
2772                                          reinterpret_cast<NativeThreadLinux*> (deferred_signal_thread_sp.get ())->SetStoppedBySignal (deferred_signo);
2773 
2774                                          // Tell the process delegate that the process is in a stopped state.
2775                                          SetState (StateType::eStateStopped, true);
2776                                      });
2777     }
2778 
2779     return error;
2780 }
2781 
2782 Error
2783 NativeProcessLinux::Halt ()
2784 {
2785     Error error;
2786 
2787     if (kill (GetID (), SIGSTOP) != 0)
2788         error.SetErrorToErrno ();
2789 
2790     return error;
2791 }
2792 
2793 Error
2794 NativeProcessLinux::Detach ()
2795 {
2796     Error error;
2797 
2798     // Tell ptrace to detach from the process.
2799     if (GetID () != LLDB_INVALID_PROCESS_ID)
2800         error = Detach (GetID ());
2801 
2802     // Stop monitoring the inferior.
2803     StopMonitor ();
2804 
2805     // No error.
2806     return error;
2807 }
2808 
2809 Error
2810 NativeProcessLinux::Signal (int signo)
2811 {
2812     Error error;
2813 
2814     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2815     if (log)
2816         log->Printf ("NativeProcessLinux::%s: sending signal %d (%s) to pid %" PRIu64,
2817                 __FUNCTION__, signo,  GetUnixSignals ().GetSignalAsCString (signo), GetID ());
2818 
2819     if (kill(GetID(), signo))
2820         error.SetErrorToErrno();
2821 
2822     return error;
2823 }
2824 
2825 Error
2826 NativeProcessLinux::Kill ()
2827 {
2828     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2829     if (log)
2830         log->Printf ("NativeProcessLinux::%s called for PID %" PRIu64, __FUNCTION__, GetID ());
2831 
2832     Error error;
2833 
2834     switch (m_state)
2835     {
2836         case StateType::eStateInvalid:
2837         case StateType::eStateExited:
2838         case StateType::eStateCrashed:
2839         case StateType::eStateDetached:
2840         case StateType::eStateUnloaded:
2841             // Nothing to do - the process is already dead.
2842             if (log)
2843                 log->Printf ("NativeProcessLinux::%s ignored for PID %" PRIu64 " due to current state: %s", __FUNCTION__, GetID (), StateAsCString (m_state));
2844             return error;
2845 
2846         case StateType::eStateConnected:
2847         case StateType::eStateAttaching:
2848         case StateType::eStateLaunching:
2849         case StateType::eStateStopped:
2850         case StateType::eStateRunning:
2851         case StateType::eStateStepping:
2852         case StateType::eStateSuspended:
2853             // We can try to kill a process in these states.
2854             break;
2855     }
2856 
2857     if (kill (GetID (), SIGKILL) != 0)
2858     {
2859         error.SetErrorToErrno ();
2860         return error;
2861     }
2862 
2863     return error;
2864 }
2865 
2866 static Error
2867 ParseMemoryRegionInfoFromProcMapsLine (const std::string &maps_line, MemoryRegionInfo &memory_region_info)
2868 {
2869     memory_region_info.Clear();
2870 
2871     StringExtractor line_extractor (maps_line.c_str ());
2872 
2873     // Format: {address_start_hex}-{address_end_hex} perms offset  dev   inode   pathname
2874     // perms: rwxp   (letter is present if set, '-' if not, final character is p=private, s=shared).
2875 
2876     // Parse out the starting address
2877     lldb::addr_t start_address = line_extractor.GetHexMaxU64 (false, 0);
2878 
2879     // Parse out hyphen separating start and end address from range.
2880     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != '-'))
2881         return Error ("malformed /proc/{pid}/maps entry, missing dash between address range");
2882 
2883     // Parse out the ending address
2884     lldb::addr_t end_address = line_extractor.GetHexMaxU64 (false, start_address);
2885 
2886     // Parse out the space after the address.
2887     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != ' '))
2888         return Error ("malformed /proc/{pid}/maps entry, missing space after range");
2889 
2890     // Save the range.
2891     memory_region_info.GetRange ().SetRangeBase (start_address);
2892     memory_region_info.GetRange ().SetRangeEnd (end_address);
2893 
2894     // Parse out each permission entry.
2895     if (line_extractor.GetBytesLeft () < 4)
2896         return Error ("malformed /proc/{pid}/maps entry, missing some portion of permissions");
2897 
2898     // Handle read permission.
2899     const char read_perm_char = line_extractor.GetChar ();
2900     if (read_perm_char == 'r')
2901         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eYes);
2902     else
2903     {
2904         assert ( (read_perm_char == '-') && "unexpected /proc/{pid}/maps read permission char" );
2905         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
2906     }
2907 
2908     // Handle write permission.
2909     const char write_perm_char = line_extractor.GetChar ();
2910     if (write_perm_char == 'w')
2911         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eYes);
2912     else
2913     {
2914         assert ( (write_perm_char == '-') && "unexpected /proc/{pid}/maps write permission char" );
2915         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
2916     }
2917 
2918     // Handle execute permission.
2919     const char exec_perm_char = line_extractor.GetChar ();
2920     if (exec_perm_char == 'x')
2921         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eYes);
2922     else
2923     {
2924         assert ( (exec_perm_char == '-') && "unexpected /proc/{pid}/maps exec permission char" );
2925         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
2926     }
2927 
2928     return Error ();
2929 }
2930 
2931 Error
2932 NativeProcessLinux::GetMemoryRegionInfo (lldb::addr_t load_addr, MemoryRegionInfo &range_info)
2933 {
2934     // FIXME review that the final memory region returned extends to the end of the virtual address space,
2935     // with no perms if it is not mapped.
2936 
2937     // Use an approach that reads memory regions from /proc/{pid}/maps.
2938     // Assume proc maps entries are in ascending order.
2939     // FIXME assert if we find differently.
2940     Mutex::Locker locker (m_mem_region_cache_mutex);
2941 
2942     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2943     Error error;
2944 
2945     if (m_supports_mem_region == LazyBool::eLazyBoolNo)
2946     {
2947         // We're done.
2948         error.SetErrorString ("unsupported");
2949         return error;
2950     }
2951 
2952     // If our cache is empty, pull the latest.  There should always be at least one memory region
2953     // if memory region handling is supported.
2954     if (m_mem_region_cache.empty ())
2955     {
2956         error = ProcFileReader::ProcessLineByLine (GetID (), "maps",
2957              [&] (const std::string &line) -> bool
2958              {
2959                  MemoryRegionInfo info;
2960                  const Error parse_error = ParseMemoryRegionInfoFromProcMapsLine (line, info);
2961                  if (parse_error.Success ())
2962                  {
2963                      m_mem_region_cache.push_back (info);
2964                      return true;
2965                  }
2966                  else
2967                  {
2968                      if (log)
2969                          log->Printf ("NativeProcessLinux::%s failed to parse proc maps line '%s': %s", __FUNCTION__, line.c_str (), error.AsCString ());
2970                      return false;
2971                  }
2972              });
2973 
2974         // If we had an error, we'll mark unsupported.
2975         if (error.Fail ())
2976         {
2977             m_supports_mem_region = LazyBool::eLazyBoolNo;
2978             return error;
2979         }
2980         else if (m_mem_region_cache.empty ())
2981         {
2982             // No entries after attempting to read them.  This shouldn't happen if /proc/{pid}/maps
2983             // is supported.  Assume we don't support map entries via procfs.
2984             if (log)
2985                 log->Printf ("NativeProcessLinux::%s failed to find any procfs maps entries, assuming no support for memory region metadata retrieval", __FUNCTION__);
2986             m_supports_mem_region = LazyBool::eLazyBoolNo;
2987             error.SetErrorString ("not supported");
2988             return error;
2989         }
2990 
2991         if (log)
2992             log->Printf ("NativeProcessLinux::%s read %" PRIu64 " memory region entries from /proc/%" PRIu64 "/maps", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()), GetID ());
2993 
2994         // We support memory retrieval, remember that.
2995         m_supports_mem_region = LazyBool::eLazyBoolYes;
2996     }
2997     else
2998     {
2999         if (log)
3000             log->Printf ("NativeProcessLinux::%s reusing %" PRIu64 " cached memory region entries", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
3001     }
3002 
3003     lldb::addr_t prev_base_address = 0;
3004 
3005     // FIXME start by finding the last region that is <= target address using binary search.  Data is sorted.
3006     // There can be a ton of regions on pthreads apps with lots of threads.
3007     for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end (); ++it)
3008     {
3009         MemoryRegionInfo &proc_entry_info = *it;
3010 
3011         // Sanity check assumption that /proc/{pid}/maps entries are ascending.
3012         assert ((proc_entry_info.GetRange ().GetRangeBase () >= prev_base_address) && "descending /proc/pid/maps entries detected, unexpected");
3013         prev_base_address = proc_entry_info.GetRange ().GetRangeBase ();
3014 
3015         // If the target address comes before this entry, indicate distance to next region.
3016         if (load_addr < proc_entry_info.GetRange ().GetRangeBase ())
3017         {
3018             range_info.GetRange ().SetRangeBase (load_addr);
3019             range_info.GetRange ().SetByteSize (proc_entry_info.GetRange ().GetRangeBase () - load_addr);
3020             range_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
3021             range_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
3022             range_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
3023 
3024             return error;
3025         }
3026         else if (proc_entry_info.GetRange ().Contains (load_addr))
3027         {
3028             // The target address is within the memory region we're processing here.
3029             range_info = proc_entry_info;
3030             return error;
3031         }
3032 
3033         // The target memory address comes somewhere after the region we just parsed.
3034     }
3035 
3036     // If we made it here, we didn't find an entry that contained the given address.
3037     error.SetErrorString ("address comes after final region");
3038 
3039     if (log)
3040         log->Printf ("NativeProcessLinux::%s failed to find map entry for address 0x%" PRIx64 ": %s", __FUNCTION__, load_addr, error.AsCString ());
3041 
3042     return error;
3043 }
3044 
3045 void
3046 NativeProcessLinux::DoStopIDBumped (uint32_t newBumpId)
3047 {
3048     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3049     if (log)
3050         log->Printf ("NativeProcessLinux::%s(newBumpId=%" PRIu32 ") called", __FUNCTION__, newBumpId);
3051 
3052     {
3053         Mutex::Locker locker (m_mem_region_cache_mutex);
3054         if (log)
3055             log->Printf ("NativeProcessLinux::%s clearing %" PRIu64 " entries from the cache", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
3056         m_mem_region_cache.clear ();
3057     }
3058 }
3059 
3060 Error
3061 NativeProcessLinux::AllocateMemory (
3062     lldb::addr_t size,
3063     uint32_t permissions,
3064     lldb::addr_t &addr)
3065 {
3066     // FIXME implementing this requires the equivalent of
3067     // InferiorCallPOSIX::InferiorCallMmap, which depends on
3068     // functional ThreadPlans working with Native*Protocol.
3069 #if 1
3070     return Error ("not implemented yet");
3071 #else
3072     addr = LLDB_INVALID_ADDRESS;
3073 
3074     unsigned prot = 0;
3075     if (permissions & lldb::ePermissionsReadable)
3076         prot |= eMmapProtRead;
3077     if (permissions & lldb::ePermissionsWritable)
3078         prot |= eMmapProtWrite;
3079     if (permissions & lldb::ePermissionsExecutable)
3080         prot |= eMmapProtExec;
3081 
3082     // TODO implement this directly in NativeProcessLinux
3083     // (and lift to NativeProcessPOSIX if/when that class is
3084     // refactored out).
3085     if (InferiorCallMmap(this, addr, 0, size, prot,
3086                          eMmapFlagsAnon | eMmapFlagsPrivate, -1, 0)) {
3087         m_addr_to_mmap_size[addr] = size;
3088         return Error ();
3089     } else {
3090         addr = LLDB_INVALID_ADDRESS;
3091         return Error("unable to allocate %" PRIu64 " bytes of memory with permissions %s", size, GetPermissionsAsCString (permissions));
3092     }
3093 #endif
3094 }
3095 
3096 Error
3097 NativeProcessLinux::DeallocateMemory (lldb::addr_t addr)
3098 {
3099     // FIXME see comments in AllocateMemory - required lower-level
3100     // bits not in place yet (ThreadPlans)
3101     return Error ("not implemented");
3102 }
3103 
3104 lldb::addr_t
3105 NativeProcessLinux::GetSharedLibraryInfoAddress ()
3106 {
3107 #if 1
3108     // punt on this for now
3109     return LLDB_INVALID_ADDRESS;
3110 #else
3111     // Return the image info address for the exe module
3112 #if 1
3113     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3114 
3115     ModuleSP module_sp;
3116     Error error = GetExeModuleSP (module_sp);
3117     if (error.Fail ())
3118     {
3119          if (log)
3120             log->Warning ("NativeProcessLinux::%s failed to retrieve exe module: %s", __FUNCTION__, error.AsCString ());
3121         return LLDB_INVALID_ADDRESS;
3122     }
3123 
3124     if (module_sp == nullptr)
3125     {
3126          if (log)
3127             log->Warning ("NativeProcessLinux::%s exe module returned was NULL", __FUNCTION__);
3128          return LLDB_INVALID_ADDRESS;
3129     }
3130 
3131     ObjectFileSP object_file_sp = module_sp->GetObjectFile ();
3132     if (object_file_sp == nullptr)
3133     {
3134          if (log)
3135             log->Warning ("NativeProcessLinux::%s exe module returned a NULL object file", __FUNCTION__);
3136          return LLDB_INVALID_ADDRESS;
3137     }
3138 
3139     return obj_file_sp->GetImageInfoAddress();
3140 #else
3141     Target *target = &GetTarget();
3142     ObjectFile *obj_file = target->GetExecutableModule()->GetObjectFile();
3143     Address addr = obj_file->GetImageInfoAddress(target);
3144 
3145     if (addr.IsValid())
3146         return addr.GetLoadAddress(target);
3147     return LLDB_INVALID_ADDRESS;
3148 #endif
3149 #endif // punt on this for now
3150 }
3151 
3152 size_t
3153 NativeProcessLinux::UpdateThreads ()
3154 {
3155     // The NativeProcessLinux monitoring threads are always up to date
3156     // with respect to thread state and they keep the thread list
3157     // populated properly. All this method needs to do is return the
3158     // thread count.
3159     Mutex::Locker locker (m_threads_mutex);
3160     return m_threads.size ();
3161 }
3162 
3163 bool
3164 NativeProcessLinux::GetArchitecture (ArchSpec &arch) const
3165 {
3166     arch = m_arch;
3167     return true;
3168 }
3169 
3170 Error
3171 NativeProcessLinux::GetSoftwareBreakpointSize (NativeRegisterContextSP context_sp, uint32_t &actual_opcode_size)
3172 {
3173     // FIXME put this behind a breakpoint protocol class that can be
3174     // set per architecture.  Need ARM, MIPS support here.
3175     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
3176     static const uint8_t g_i386_opcode [] = { 0xCC };
3177 
3178     switch (m_arch.GetMachine ())
3179     {
3180         case llvm::Triple::aarch64:
3181             actual_opcode_size = static_cast<uint32_t> (sizeof(g_aarch64_opcode));
3182             return Error ();
3183 
3184         case llvm::Triple::x86:
3185         case llvm::Triple::x86_64:
3186             actual_opcode_size = static_cast<uint32_t> (sizeof(g_i386_opcode));
3187             return Error ();
3188 
3189         default:
3190             assert(false && "CPU type not supported!");
3191             return Error ("CPU type not supported");
3192     }
3193 }
3194 
3195 Error
3196 NativeProcessLinux::SetBreakpoint (lldb::addr_t addr, uint32_t size, bool hardware)
3197 {
3198     if (hardware)
3199         return Error ("NativeProcessLinux does not support hardware breakpoints");
3200     else
3201         return SetSoftwareBreakpoint (addr, size);
3202 }
3203 
3204 Error
3205 NativeProcessLinux::GetSoftwareBreakpointTrapOpcode (size_t trap_opcode_size_hint, size_t &actual_opcode_size, const uint8_t *&trap_opcode_bytes)
3206 {
3207     // FIXME put this behind a breakpoint protocol class that can be
3208     // set per architecture.  Need ARM, MIPS support here.
3209     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
3210     static const uint8_t g_i386_opcode [] = { 0xCC };
3211 
3212     switch (m_arch.GetMachine ())
3213     {
3214     case llvm::Triple::aarch64:
3215         trap_opcode_bytes = g_aarch64_opcode;
3216         actual_opcode_size = sizeof(g_aarch64_opcode);
3217         return Error ();
3218 
3219     case llvm::Triple::x86:
3220     case llvm::Triple::x86_64:
3221         trap_opcode_bytes = g_i386_opcode;
3222         actual_opcode_size = sizeof(g_i386_opcode);
3223         return Error ();
3224 
3225     default:
3226         assert(false && "CPU type not supported!");
3227         return Error ("CPU type not supported");
3228     }
3229 }
3230 
3231 #if 0
3232 ProcessMessage::CrashReason
3233 NativeProcessLinux::GetCrashReasonForSIGSEGV(const siginfo_t *info)
3234 {
3235     ProcessMessage::CrashReason reason;
3236     assert(info->si_signo == SIGSEGV);
3237 
3238     reason = ProcessMessage::eInvalidCrashReason;
3239 
3240     switch (info->si_code)
3241     {
3242     default:
3243         assert(false && "unexpected si_code for SIGSEGV");
3244         break;
3245     case SI_KERNEL:
3246         // Linux will occasionally send spurious SI_KERNEL codes.
3247         // (this is poorly documented in sigaction)
3248         // One way to get this is via unaligned SIMD loads.
3249         reason = ProcessMessage::eInvalidAddress; // for lack of anything better
3250         break;
3251     case SEGV_MAPERR:
3252         reason = ProcessMessage::eInvalidAddress;
3253         break;
3254     case SEGV_ACCERR:
3255         reason = ProcessMessage::ePrivilegedAddress;
3256         break;
3257     }
3258 
3259     return reason;
3260 }
3261 #endif
3262 
3263 
3264 #if 0
3265 ProcessMessage::CrashReason
3266 NativeProcessLinux::GetCrashReasonForSIGILL(const siginfo_t *info)
3267 {
3268     ProcessMessage::CrashReason reason;
3269     assert(info->si_signo == SIGILL);
3270 
3271     reason = ProcessMessage::eInvalidCrashReason;
3272 
3273     switch (info->si_code)
3274     {
3275     default:
3276         assert(false && "unexpected si_code for SIGILL");
3277         break;
3278     case ILL_ILLOPC:
3279         reason = ProcessMessage::eIllegalOpcode;
3280         break;
3281     case ILL_ILLOPN:
3282         reason = ProcessMessage::eIllegalOperand;
3283         break;
3284     case ILL_ILLADR:
3285         reason = ProcessMessage::eIllegalAddressingMode;
3286         break;
3287     case ILL_ILLTRP:
3288         reason = ProcessMessage::eIllegalTrap;
3289         break;
3290     case ILL_PRVOPC:
3291         reason = ProcessMessage::ePrivilegedOpcode;
3292         break;
3293     case ILL_PRVREG:
3294         reason = ProcessMessage::ePrivilegedRegister;
3295         break;
3296     case ILL_COPROC:
3297         reason = ProcessMessage::eCoprocessorError;
3298         break;
3299     case ILL_BADSTK:
3300         reason = ProcessMessage::eInternalStackError;
3301         break;
3302     }
3303 
3304     return reason;
3305 }
3306 #endif
3307 
3308 #if 0
3309 ProcessMessage::CrashReason
3310 NativeProcessLinux::GetCrashReasonForSIGFPE(const siginfo_t *info)
3311 {
3312     ProcessMessage::CrashReason reason;
3313     assert(info->si_signo == SIGFPE);
3314 
3315     reason = ProcessMessage::eInvalidCrashReason;
3316 
3317     switch (info->si_code)
3318     {
3319     default:
3320         assert(false && "unexpected si_code for SIGFPE");
3321         break;
3322     case FPE_INTDIV:
3323         reason = ProcessMessage::eIntegerDivideByZero;
3324         break;
3325     case FPE_INTOVF:
3326         reason = ProcessMessage::eIntegerOverflow;
3327         break;
3328     case FPE_FLTDIV:
3329         reason = ProcessMessage::eFloatDivideByZero;
3330         break;
3331     case FPE_FLTOVF:
3332         reason = ProcessMessage::eFloatOverflow;
3333         break;
3334     case FPE_FLTUND:
3335         reason = ProcessMessage::eFloatUnderflow;
3336         break;
3337     case FPE_FLTRES:
3338         reason = ProcessMessage::eFloatInexactResult;
3339         break;
3340     case FPE_FLTINV:
3341         reason = ProcessMessage::eFloatInvalidOperation;
3342         break;
3343     case FPE_FLTSUB:
3344         reason = ProcessMessage::eFloatSubscriptRange;
3345         break;
3346     }
3347 
3348     return reason;
3349 }
3350 #endif
3351 
3352 #if 0
3353 ProcessMessage::CrashReason
3354 NativeProcessLinux::GetCrashReasonForSIGBUS(const siginfo_t *info)
3355 {
3356     ProcessMessage::CrashReason reason;
3357     assert(info->si_signo == SIGBUS);
3358 
3359     reason = ProcessMessage::eInvalidCrashReason;
3360 
3361     switch (info->si_code)
3362     {
3363     default:
3364         assert(false && "unexpected si_code for SIGBUS");
3365         break;
3366     case BUS_ADRALN:
3367         reason = ProcessMessage::eIllegalAlignment;
3368         break;
3369     case BUS_ADRERR:
3370         reason = ProcessMessage::eIllegalAddress;
3371         break;
3372     case BUS_OBJERR:
3373         reason = ProcessMessage::eHardwareError;
3374         break;
3375     }
3376 
3377     return reason;
3378 }
3379 #endif
3380 
3381 void
3382 NativeProcessLinux::ServeOperation(OperationArgs *args)
3383 {
3384     NativeProcessLinux *monitor = args->m_monitor;
3385 
3386     // We are finised with the arguments and are ready to go.  Sync with the
3387     // parent thread and start serving operations on the inferior.
3388     sem_post(&args->m_semaphore);
3389 
3390     for(;;)
3391     {
3392         // wait for next pending operation
3393         if (sem_wait(&monitor->m_operation_pending))
3394         {
3395             if (errno == EINTR)
3396                 continue;
3397             assert(false && "Unexpected errno from sem_wait");
3398         }
3399 
3400         reinterpret_cast<Operation*>(monitor->m_operation)->Execute(monitor);
3401 
3402         // notify calling thread that operation is complete
3403         sem_post(&monitor->m_operation_done);
3404     }
3405 }
3406 
3407 void
3408 NativeProcessLinux::DoOperation(void *op)
3409 {
3410     Mutex::Locker lock(m_operation_mutex);
3411 
3412     m_operation = op;
3413 
3414     // notify operation thread that an operation is ready to be processed
3415     sem_post(&m_operation_pending);
3416 
3417     // wait for operation to complete
3418     while (sem_wait(&m_operation_done))
3419     {
3420         if (errno == EINTR)
3421             continue;
3422         assert(false && "Unexpected errno from sem_wait");
3423     }
3424 }
3425 
3426 Error
3427 NativeProcessLinux::ReadMemory (lldb::addr_t addr, void *buf, lldb::addr_t size, lldb::addr_t &bytes_read)
3428 {
3429     ReadOperation op(addr, buf, size, bytes_read);
3430     DoOperation(&op);
3431     return op.GetError ();
3432 }
3433 
3434 Error
3435 NativeProcessLinux::WriteMemory (lldb::addr_t addr, const void *buf, lldb::addr_t size, lldb::addr_t &bytes_written)
3436 {
3437     WriteOperation op(addr, buf, size, bytes_written);
3438     DoOperation(&op);
3439     return op.GetError ();
3440 }
3441 
3442 bool
3443 NativeProcessLinux::ReadRegisterValue(lldb::tid_t tid, uint32_t offset, const char* reg_name,
3444                                   uint32_t size, RegisterValue &value)
3445 {
3446     bool result;
3447     ReadRegOperation op(tid, offset, reg_name, value, result);
3448     DoOperation(&op);
3449     return result;
3450 }
3451 
3452 bool
3453 NativeProcessLinux::WriteRegisterValue(lldb::tid_t tid, unsigned offset,
3454                                    const char* reg_name, const RegisterValue &value)
3455 {
3456     bool result;
3457     WriteRegOperation op(tid, offset, reg_name, value, result);
3458     DoOperation(&op);
3459     return result;
3460 }
3461 
3462 bool
3463 NativeProcessLinux::ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3464 {
3465     bool result;
3466     ReadGPROperation op(tid, buf, buf_size, result);
3467     DoOperation(&op);
3468     return result;
3469 }
3470 
3471 bool
3472 NativeProcessLinux::ReadFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3473 {
3474     bool result;
3475     ReadFPROperation op(tid, buf, buf_size, result);
3476     DoOperation(&op);
3477     return result;
3478 }
3479 
3480 bool
3481 NativeProcessLinux::ReadRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3482 {
3483     bool result;
3484     ReadRegisterSetOperation op(tid, buf, buf_size, regset, result);
3485     DoOperation(&op);
3486     return result;
3487 }
3488 
3489 bool
3490 NativeProcessLinux::WriteGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3491 {
3492     bool result;
3493     WriteGPROperation op(tid, buf, buf_size, result);
3494     DoOperation(&op);
3495     return result;
3496 }
3497 
3498 bool
3499 NativeProcessLinux::WriteFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3500 {
3501     bool result;
3502     WriteFPROperation op(tid, buf, buf_size, result);
3503     DoOperation(&op);
3504     return result;
3505 }
3506 
3507 bool
3508 NativeProcessLinux::WriteRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3509 {
3510     bool result;
3511     WriteRegisterSetOperation op(tid, buf, buf_size, regset, result);
3512     DoOperation(&op);
3513     return result;
3514 }
3515 
3516 bool
3517 NativeProcessLinux::Resume (lldb::tid_t tid, uint32_t signo)
3518 {
3519     bool result;
3520     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3521 
3522     if (log)
3523         log->Printf ("NativeProcessLinux::%s() resuming thread = %"  PRIu64 " with signal %s", __FUNCTION__, tid,
3524                                  GetUnixSignals().GetSignalAsCString (signo));
3525     ResumeOperation op (tid, signo, result);
3526     DoOperation (&op);
3527     if (log)
3528         log->Printf ("NativeProcessLinux::%s() resuming result = %s", __FUNCTION__, result ? "true" : "false");
3529     return result;
3530 }
3531 
3532 bool
3533 NativeProcessLinux::SingleStep(lldb::tid_t tid, uint32_t signo)
3534 {
3535     bool result;
3536     SingleStepOperation op(tid, signo, result);
3537     DoOperation(&op);
3538     return result;
3539 }
3540 
3541 bool
3542 NativeProcessLinux::GetSignalInfo(lldb::tid_t tid, void *siginfo, int &ptrace_err)
3543 {
3544     bool result;
3545     SiginfoOperation op(tid, siginfo, result, ptrace_err);
3546     DoOperation(&op);
3547     return result;
3548 }
3549 
3550 bool
3551 NativeProcessLinux::GetEventMessage(lldb::tid_t tid, unsigned long *message)
3552 {
3553     bool result;
3554     EventMessageOperation op(tid, message, result);
3555     DoOperation(&op);
3556     return result;
3557 }
3558 
3559 lldb_private::Error
3560 NativeProcessLinux::Detach(lldb::tid_t tid)
3561 {
3562     lldb_private::Error error;
3563     if (tid != LLDB_INVALID_THREAD_ID)
3564     {
3565         DetachOperation op(tid, error);
3566         DoOperation(&op);
3567     }
3568     return error;
3569 }
3570 
3571 bool
3572 NativeProcessLinux::DupDescriptor(const char *path, int fd, int flags)
3573 {
3574     int target_fd = open(path, flags, 0666);
3575 
3576     if (target_fd == -1)
3577         return false;
3578 
3579     return (dup2(target_fd, fd) == -1) ? false : true;
3580 }
3581 
3582 void
3583 NativeProcessLinux::StopMonitoringChildProcess()
3584 {
3585     if (m_monitor_thread.IsJoinable())
3586     {
3587         m_monitor_thread.Cancel();
3588         m_monitor_thread.Join(nullptr);
3589     }
3590 }
3591 
3592 void
3593 NativeProcessLinux::StopMonitor()
3594 {
3595     StopMonitoringChildProcess();
3596     StopOpThread();
3597     StopCoordinatorThread ();
3598     sem_destroy(&m_operation_pending);
3599     sem_destroy(&m_operation_done);
3600 
3601     // TODO: validate whether this still holds, fix up comment.
3602     // Note: ProcessPOSIX passes the m_terminal_fd file descriptor to
3603     // Process::SetSTDIOFileDescriptor, which in turn transfers ownership of
3604     // the descriptor to a ConnectionFileDescriptor object.  Consequently
3605     // even though still has the file descriptor, we shouldn't close it here.
3606 }
3607 
3608 void
3609 NativeProcessLinux::StopOpThread()
3610 {
3611     if (!m_operation_thread.IsJoinable())
3612         return;
3613 
3614     m_operation_thread.Cancel();
3615     m_operation_thread.Join(nullptr);
3616 }
3617 
3618 Error
3619 NativeProcessLinux::StartCoordinatorThread ()
3620 {
3621     Error error;
3622     static const char *g_thread_name = "lldb.process.linux.ts_coordinator";
3623     Log *const log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3624 
3625     // Skip if thread is already running
3626     if (m_coordinator_thread.IsJoinable())
3627     {
3628         error.SetErrorString ("ThreadStateCoordinator's run loop is already running");
3629         if (log)
3630             log->Printf ("NativeProcessLinux::%s %s", __FUNCTION__, error.AsCString ());
3631         return error;
3632     }
3633 
3634     // Enable verbose logging if lldb thread logging is enabled.
3635     m_coordinator_up->LogEnableEventProcessing (log != nullptr);
3636 
3637     if (log)
3638         log->Printf ("NativeProcessLinux::%s launching ThreadStateCoordinator thread for pid %" PRIu64, __FUNCTION__, GetID ());
3639     m_coordinator_thread = ThreadLauncher::LaunchThread(g_thread_name, CoordinatorThread, this, &error);
3640     return error;
3641 }
3642 
3643 void *
3644 NativeProcessLinux::CoordinatorThread (void *arg)
3645 {
3646     Log *const log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3647 
3648     NativeProcessLinux *const process = static_cast<NativeProcessLinux*> (arg);
3649     assert (process && "null process passed to CoordinatorThread");
3650     if (!process)
3651     {
3652         if (log)
3653             log->Printf ("NativeProcessLinux::%s null process, exiting ThreadStateCoordinator processing loop", __FUNCTION__);
3654         return nullptr;
3655     }
3656 
3657     // Run the thread state coordinator loop until it is done.  This call uses
3658     // efficient waiting for an event to be ready.
3659     while (process->m_coordinator_up->ProcessNextEvent () == ThreadStateCoordinator::eventLoopResultContinue)
3660     {
3661     }
3662 
3663     if (log)
3664         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " exiting ThreadStateCoordinator processing loop due to coordinator indicating completion", __FUNCTION__, process->GetID ());
3665 
3666     return nullptr;
3667 }
3668 
3669 void
3670 NativeProcessLinux::StopCoordinatorThread()
3671 {
3672     Log *const log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3673     if (log)
3674         log->Printf ("NativeProcessLinux::%s requesting ThreadStateCoordinator stop for pid %" PRIu64, __FUNCTION__, GetID ());
3675 
3676     // Tell the coordinator we're done.  This will cause the coordinator
3677     // run loop thread to exit when the processing queue hits this message.
3678     m_coordinator_up->StopCoordinator ();
3679 }
3680 
3681 bool
3682 NativeProcessLinux::HasThreadNoLock (lldb::tid_t thread_id)
3683 {
3684     for (auto thread_sp : m_threads)
3685     {
3686         assert (thread_sp && "thread list should not contain NULL threads");
3687         if (thread_sp->GetID () == thread_id)
3688         {
3689             // We have this thread.
3690             return true;
3691         }
3692     }
3693 
3694     // We don't have this thread.
3695     return false;
3696 }
3697 
3698 NativeThreadProtocolSP
3699 NativeProcessLinux::MaybeGetThreadNoLock (lldb::tid_t thread_id)
3700 {
3701     // CONSIDER organize threads by map - we can do better than linear.
3702     for (auto thread_sp : m_threads)
3703     {
3704         if (thread_sp->GetID () == thread_id)
3705             return thread_sp;
3706     }
3707 
3708     // We don't have this thread.
3709     return NativeThreadProtocolSP ();
3710 }
3711 
3712 bool
3713 NativeProcessLinux::StopTrackingThread (lldb::tid_t thread_id)
3714 {
3715     Mutex::Locker locker (m_threads_mutex);
3716     for (auto it = m_threads.begin (); it != m_threads.end (); ++it)
3717     {
3718         if (*it && ((*it)->GetID () == thread_id))
3719         {
3720             m_threads.erase (it);
3721             return true;
3722         }
3723     }
3724 
3725     // Didn't find it.
3726     return false;
3727 }
3728 
3729 NativeThreadProtocolSP
3730 NativeProcessLinux::AddThread (lldb::tid_t thread_id)
3731 {
3732     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3733 
3734     Mutex::Locker locker (m_threads_mutex);
3735 
3736     if (log)
3737     {
3738         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " adding thread with tid %" PRIu64,
3739                 __FUNCTION__,
3740                 GetID (),
3741                 thread_id);
3742     }
3743 
3744     assert (!HasThreadNoLock (thread_id) && "attempted to add a thread by id that already exists");
3745 
3746     // If this is the first thread, save it as the current thread
3747     if (m_threads.empty ())
3748         SetCurrentThreadID (thread_id);
3749 
3750     NativeThreadProtocolSP thread_sp (new NativeThreadLinux (this, thread_id));
3751     m_threads.push_back (thread_sp);
3752 
3753     return thread_sp;
3754 }
3755 
3756 NativeThreadProtocolSP
3757 NativeProcessLinux::GetOrCreateThread (lldb::tid_t thread_id, bool &created)
3758 {
3759     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3760 
3761     Mutex::Locker locker (m_threads_mutex);
3762     if (log)
3763     {
3764         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " get/create thread with tid %" PRIu64,
3765                      __FUNCTION__,
3766                      GetID (),
3767                      thread_id);
3768     }
3769 
3770     // Retrieve the thread if it is already getting tracked.
3771     NativeThreadProtocolSP thread_sp = MaybeGetThreadNoLock (thread_id);
3772     if (thread_sp)
3773     {
3774         if (log)
3775             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread already tracked, returning",
3776                          __FUNCTION__,
3777                          GetID (),
3778                          thread_id);
3779         created = false;
3780         return thread_sp;
3781 
3782     }
3783 
3784     // Create the thread metadata since it isn't being tracked.
3785     if (log)
3786         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread didn't exist, tracking now",
3787                      __FUNCTION__,
3788                      GetID (),
3789                      thread_id);
3790 
3791     thread_sp.reset (new NativeThreadLinux (this, thread_id));
3792     m_threads.push_back (thread_sp);
3793     created = true;
3794 
3795     return thread_sp;
3796 }
3797 
3798 Error
3799 NativeProcessLinux::FixupBreakpointPCAsNeeded (NativeThreadProtocolSP &thread_sp)
3800 {
3801     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_BREAKPOINTS));
3802 
3803     Error error;
3804 
3805     // Get a linux thread pointer.
3806     if (!thread_sp)
3807     {
3808         error.SetErrorString ("null thread_sp");
3809         if (log)
3810             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3811         return error;
3812     }
3813     NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get());
3814 
3815     // Find out the size of a breakpoint (might depend on where we are in the code).
3816     NativeRegisterContextSP context_sp = linux_thread_p->GetRegisterContext ();
3817     if (!context_sp)
3818     {
3819         error.SetErrorString ("cannot get a NativeRegisterContext for the thread");
3820         if (log)
3821             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3822         return error;
3823     }
3824 
3825     uint32_t breakpoint_size = 0;
3826     error = GetSoftwareBreakpointSize (context_sp, breakpoint_size);
3827     if (error.Fail ())
3828     {
3829         if (log)
3830             log->Printf ("NativeProcessLinux::%s GetBreakpointSize() failed: %s", __FUNCTION__, error.AsCString ());
3831         return error;
3832     }
3833     else
3834     {
3835         if (log)
3836             log->Printf ("NativeProcessLinux::%s breakpoint size: %" PRIu32, __FUNCTION__, breakpoint_size);
3837     }
3838 
3839     // First try probing for a breakpoint at a software breakpoint location: PC - breakpoint size.
3840     const lldb::addr_t initial_pc_addr = context_sp->GetPC ();
3841     lldb::addr_t breakpoint_addr = initial_pc_addr;
3842     if (breakpoint_size > static_cast<lldb::addr_t> (0))
3843     {
3844         // Do not allow breakpoint probe to wrap around.
3845         if (breakpoint_addr >= static_cast<lldb::addr_t> (breakpoint_size))
3846             breakpoint_addr -= static_cast<lldb::addr_t> (breakpoint_size);
3847     }
3848 
3849     // Check if we stopped because of a breakpoint.
3850     NativeBreakpointSP breakpoint_sp;
3851     error = m_breakpoint_list.GetBreakpoint (breakpoint_addr, breakpoint_sp);
3852     if (!error.Success () || !breakpoint_sp)
3853     {
3854         // We didn't find one at a software probe location.  Nothing to do.
3855         if (log)
3856             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " no lldb breakpoint found at current pc with adjustment: 0x%" PRIx64, __FUNCTION__, GetID (), breakpoint_addr);
3857         return Error ();
3858     }
3859 
3860     // If the breakpoint is not a software breakpoint, nothing to do.
3861     if (!breakpoint_sp->IsSoftwareBreakpoint ())
3862     {
3863         if (log)
3864             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " breakpoint found at 0x%" PRIx64 ", not software, nothing to adjust", __FUNCTION__, GetID (), breakpoint_addr);
3865         return Error ();
3866     }
3867 
3868     //
3869     // We have a software breakpoint and need to adjust the PC.
3870     //
3871 
3872     // Sanity check.
3873     if (breakpoint_size == 0)
3874     {
3875         // Nothing to do!  How did we get here?
3876         if (log)
3877             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " breakpoint found at 0x%" PRIx64 ", it is software, but the size is zero, nothing to do (unexpected)", __FUNCTION__, GetID (), breakpoint_addr);
3878         return Error ();
3879     }
3880 
3881     // Change the program counter.
3882     if (log)
3883         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": changing PC from 0x%" PRIx64 " to 0x%" PRIx64, __FUNCTION__, GetID (), linux_thread_p->GetID (), initial_pc_addr, breakpoint_addr);
3884 
3885     error = context_sp->SetPC (breakpoint_addr);
3886     if (error.Fail ())
3887     {
3888         if (log)
3889             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": failed to set PC: %s", __FUNCTION__, GetID (), linux_thread_p->GetID (), error.AsCString ());
3890         return error;
3891     }
3892 
3893     return error;
3894 }
3895 
3896 void
3897 NativeProcessLinux::NotifyThreadCreateStopped (lldb::tid_t tid)
3898 {
3899     const bool is_stopped = true;
3900     m_coordinator_up->NotifyThreadCreate (tid, is_stopped, CoordinatorErrorHandler);
3901 }
3902 
3903 void
3904 NativeProcessLinux::NotifyThreadDeath (lldb::tid_t tid)
3905 {
3906     m_coordinator_up->NotifyThreadDeath (tid, CoordinatorErrorHandler);
3907 }
3908 
3909 void
3910 NativeProcessLinux::NotifyThreadStop (lldb::tid_t tid)
3911 {
3912     m_coordinator_up->NotifyThreadStop (tid, CoordinatorErrorHandler);
3913 }
3914 
3915 void
3916 NativeProcessLinux::CallAfterRunningThreadsStop (lldb::tid_t tid,
3917                                                  const std::function<void (lldb::tid_t tid)> &call_after_function)
3918 {
3919     const lldb::pid_t pid = GetID ();
3920     m_coordinator_up->CallAfterRunningThreadsStop (tid,
3921                                                    [=](lldb::tid_t request_stop_tid)
3922                                                    {
3923                                                        tgkill (pid, request_stop_tid, SIGSTOP);
3924                                                    },
3925                                                    call_after_function,
3926                                                    CoordinatorErrorHandler);
3927 }
3928 
3929 void
3930 NativeProcessLinux::CallAfterRunningThreadsStopWithSkipTID (lldb::tid_t deferred_signal_tid,
3931                                                             lldb::tid_t skip_stop_request_tid,
3932                                                             const std::function<void (lldb::tid_t tid)> &call_after_function)
3933 {
3934     const lldb::pid_t pid = GetID ();
3935     m_coordinator_up->CallAfterRunningThreadsStopWithSkipTIDs (deferred_signal_tid,
3936                                                                skip_stop_request_tid != LLDB_INVALID_THREAD_ID ? ThreadStateCoordinator::ThreadIDSet {skip_stop_request_tid} : ThreadStateCoordinator::ThreadIDSet (),
3937                                                                [=](lldb::tid_t request_stop_tid)
3938                                                                {
3939                                                                    tgkill (pid, request_stop_tid, SIGSTOP);
3940                                                                },
3941                                                                call_after_function,
3942                                                                CoordinatorErrorHandler);
3943 }
3944