xref: /llvm-project/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp (revision a9882cee50d3ba5716ca39ba831b43ea82c34183)
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 #include <sys/personality.h>
22 #include <sys/ptrace.h>
23 #include <sys/uio.h>
24 #include <sys/socket.h>
25 #include <sys/syscall.h>
26 #include <sys/types.h>
27 #include <sys/user.h>
28 #include <sys/wait.h>
29 
30 #if defined (__arm64__) || defined (__aarch64__)
31 // NT_PRSTATUS and NT_FPREGSET definition
32 #include <elf.h>
33 #endif
34 
35 // C++ Includes
36 #include <fstream>
37 #include <string>
38 
39 // Other libraries and framework includes
40 #include "lldb/Core/Debugger.h"
41 #include "lldb/Core/Error.h"
42 #include "lldb/Core/Module.h"
43 #include "lldb/Core/RegisterValue.h"
44 #include "lldb/Core/Scalar.h"
45 #include "lldb/Core/State.h"
46 #include "lldb/Host/Host.h"
47 #include "lldb/Host/HostInfo.h"
48 #include "lldb/Symbol/ObjectFile.h"
49 #include "lldb/Target/NativeRegisterContext.h"
50 #include "lldb/Target/ProcessLaunchInfo.h"
51 #include "lldb/Utility/PseudoTerminal.h"
52 
53 #include "Host/common/NativeBreakpoint.h"
54 #include "Utility/StringExtractor.h"
55 
56 #include "Plugins/Process/Utility/LinuxSignals.h"
57 #include "NativeThreadLinux.h"
58 #include "ProcFileReader.h"
59 #include "ProcessPOSIXLog.h"
60 
61 #define DEBUG_PTRACE_MAXBYTES 20
62 
63 // Support ptrace extensions even when compiled without required kernel support
64 #ifndef PT_GETREGS
65 #ifndef PTRACE_GETREGS
66   #define PTRACE_GETREGS 12
67 #endif
68 #endif
69 #ifndef PT_SETREGS
70 #ifndef PTRACE_SETREGS
71   #define PTRACE_SETREGS 13
72 #endif
73 #endif
74 #ifndef PT_GETFPREGS
75 #ifndef PTRACE_GETFPREGS
76   #define PTRACE_GETFPREGS 14
77 #endif
78 #endif
79 #ifndef PT_SETFPREGS
80 #ifndef PTRACE_SETFPREGS
81   #define PTRACE_SETFPREGS 15
82 #endif
83 #endif
84 #ifndef PTRACE_GETREGSET
85   #define PTRACE_GETREGSET 0x4204
86 #endif
87 #ifndef PTRACE_SETREGSET
88   #define PTRACE_SETREGSET 0x4205
89 #endif
90 #ifndef PTRACE_GET_THREAD_AREA
91   #define PTRACE_GET_THREAD_AREA 25
92 #endif
93 #ifndef PTRACE_ARCH_PRCTL
94   #define PTRACE_ARCH_PRCTL      30
95 #endif
96 #ifndef ARCH_GET_FS
97   #define ARCH_SET_GS 0x1001
98   #define ARCH_SET_FS 0x1002
99   #define ARCH_GET_FS 0x1003
100   #define ARCH_GET_GS 0x1004
101 #endif
102 
103 #define LLDB_PERSONALITY_GET_CURRENT_SETTINGS  0xffffffff
104 
105 // Support hardware breakpoints in case it has not been defined
106 #ifndef TRAP_HWBKPT
107   #define TRAP_HWBKPT 4
108 #endif
109 
110 // Try to define a macro to encapsulate the tgkill syscall
111 // fall back on kill() if tgkill isn't available
112 #define tgkill(pid, tid, sig)  syscall(SYS_tgkill, pid, tid, sig)
113 
114 // We disable the tracing of ptrace calls for integration builds to
115 // avoid the additional indirection and checks.
116 #ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
117 #define PTRACE(req, pid, addr, data, data_size) \
118     PtraceWrapper((req), (pid), (addr), (data), (data_size), #req, __FILE__, __LINE__)
119 #else
120 #define PTRACE(req, pid, addr, data, data_size) \
121     PtraceWrapper((req), (pid), (addr), (data), (data_size))
122 #endif
123 
124 // Private bits we only need internally.
125 namespace
126 {
127     using namespace lldb;
128     using namespace lldb_private;
129 
130     const UnixSignals&
131     GetUnixSignals ()
132     {
133         static process_linux::LinuxSignals signals;
134         return signals;
135     }
136 
137     const char *
138     GetFilePath(const lldb_private::FileAction *file_action, const char *default_path)
139     {
140         const char *pts_name = "/dev/pts/";
141         const char *path = NULL;
142 
143         if (file_action)
144         {
145             if (file_action->GetAction() == FileAction::eFileActionOpen)
146             {
147                 path = file_action->GetPath ();
148                 // By default the stdio paths passed in will be pseudo-terminal
149                 // (/dev/pts). If so, convert to using a different default path
150                 // instead to redirect I/O to the debugger console. This should
151                 //  also handle user overrides to /dev/null or a different file.
152                 if (!path || ::strncmp (path, pts_name, ::strlen (pts_name)) == 0)
153                     path = default_path;
154             }
155         }
156 
157         return path;
158     }
159 
160     Error
161     ResolveProcessArchitecture (lldb::pid_t pid, Platform &platform, ArchSpec &arch)
162     {
163         // Grab process info for the running process.
164         ProcessInstanceInfo process_info;
165         if (!platform.GetProcessInfo (pid, process_info))
166             return lldb_private::Error("failed to get process info");
167 
168         // Resolve the executable module.
169         ModuleSP exe_module_sp;
170         FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths ());
171         Error error = platform.ResolveExecutable(
172             process_info.GetExecutableFile (),
173             platform.GetSystemArchitecture (),
174             exe_module_sp,
175             executable_search_paths.GetSize () ? &executable_search_paths : NULL);
176 
177         if (!error.Success ())
178             return error;
179 
180         // Check if we've got our architecture from the exe_module.
181         arch = exe_module_sp->GetArchitecture ();
182         if (arch.IsValid ())
183             return Error();
184         else
185             return Error("failed to retrieve a valid architecture from the exe module");
186     }
187 
188     void
189     DisplayBytes (lldb_private::StreamString &s, void *bytes, uint32_t count)
190     {
191         uint8_t *ptr = (uint8_t *)bytes;
192         const uint32_t loop_count = std::min<uint32_t>(DEBUG_PTRACE_MAXBYTES, count);
193         for(uint32_t i=0; i<loop_count; i++)
194         {
195             s.Printf ("[%x]", *ptr);
196             ptr++;
197         }
198     }
199 
200     void
201     PtraceDisplayBytes(int &req, void *data, size_t data_size)
202     {
203         StreamString buf;
204         Log *verbose_log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (
205                     POSIX_LOG_PTRACE | POSIX_LOG_VERBOSE));
206 
207         if (verbose_log)
208         {
209             switch(req)
210             {
211             case PTRACE_POKETEXT:
212             {
213                 DisplayBytes(buf, &data, 8);
214                 verbose_log->Printf("PTRACE_POKETEXT %s", buf.GetData());
215                 break;
216             }
217             case PTRACE_POKEDATA:
218             {
219                 DisplayBytes(buf, &data, 8);
220                 verbose_log->Printf("PTRACE_POKEDATA %s", buf.GetData());
221                 break;
222             }
223             case PTRACE_POKEUSER:
224             {
225                 DisplayBytes(buf, &data, 8);
226                 verbose_log->Printf("PTRACE_POKEUSER %s", buf.GetData());
227                 break;
228             }
229             case PTRACE_SETREGS:
230             {
231                 DisplayBytes(buf, data, data_size);
232                 verbose_log->Printf("PTRACE_SETREGS %s", buf.GetData());
233                 break;
234             }
235             case PTRACE_SETFPREGS:
236             {
237                 DisplayBytes(buf, data, data_size);
238                 verbose_log->Printf("PTRACE_SETFPREGS %s", buf.GetData());
239                 break;
240             }
241             case PTRACE_SETSIGINFO:
242             {
243                 DisplayBytes(buf, data, sizeof(siginfo_t));
244                 verbose_log->Printf("PTRACE_SETSIGINFO %s", buf.GetData());
245                 break;
246             }
247             case PTRACE_SETREGSET:
248             {
249                 // Extract iov_base from data, which is a pointer to the struct IOVEC
250                 DisplayBytes(buf, *(void **)data, data_size);
251                 verbose_log->Printf("PTRACE_SETREGSET %s", buf.GetData());
252                 break;
253             }
254             default:
255             {
256             }
257             }
258         }
259     }
260 
261     // Wrapper for ptrace to catch errors and log calls.
262     // Note that ptrace sets errno on error because -1 can be a valid result (i.e. for PTRACE_PEEK*)
263     long
264     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size,
265             const char* reqName, const char* file, int line)
266     {
267         long int result;
268 
269         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PTRACE));
270 
271         PtraceDisplayBytes(req, data, data_size);
272 
273         errno = 0;
274         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
275             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
276         else
277             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
278 
279         if (log)
280             log->Printf("ptrace(%s, %" PRIu64 ", %p, %p, %zu)=%lX called from file %s line %d",
281                     reqName, pid, addr, data, data_size, result, file, line);
282 
283         PtraceDisplayBytes(req, data, data_size);
284 
285         if (log && errno != 0)
286         {
287             const char* str;
288             switch (errno)
289             {
290             case ESRCH:  str = "ESRCH"; break;
291             case EINVAL: str = "EINVAL"; break;
292             case EBUSY:  str = "EBUSY"; break;
293             case EPERM:  str = "EPERM"; break;
294             default:     str = "<unknown>";
295             }
296             log->Printf("ptrace() failed; errno=%d (%s)", errno, str);
297         }
298 
299         return result;
300     }
301 
302 #ifdef LLDB_CONFIGURATION_BUILDANDINTEGRATION
303     // Wrapper for ptrace when logging is not required.
304     // Sets errno to 0 prior to calling ptrace.
305     long
306     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size)
307     {
308         long result = 0;
309         errno = 0;
310         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
311             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
312         else
313             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
314         return result;
315     }
316 #endif
317 
318     //------------------------------------------------------------------------------
319     // Static implementations of NativeProcessLinux::ReadMemory and
320     // NativeProcessLinux::WriteMemory.  This enables mutual recursion between these
321     // functions without needed to go thru the thread funnel.
322 
323     static lldb::addr_t
324     DoReadMemory (
325         lldb::pid_t pid,
326         lldb::addr_t vm_addr,
327         void *buf,
328         lldb::addr_t size,
329         Error &error)
330     {
331         // ptrace word size is determined by the host, not the child
332         static const unsigned word_size = sizeof(void*);
333         unsigned char *dst = static_cast<unsigned char*>(buf);
334         lldb::addr_t bytes_read;
335         lldb::addr_t remainder;
336         long data;
337 
338         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
339         if (log)
340             ProcessPOSIXLog::IncNestLevel();
341         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
342             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %d, %p, %p, %zd, _)", __FUNCTION__,
343                     pid, word_size, (void*)vm_addr, buf, size);
344 
345         assert(sizeof(data) >= word_size);
346         for (bytes_read = 0; bytes_read < size; bytes_read += remainder)
347         {
348             errno = 0;
349             data = PTRACE(PTRACE_PEEKDATA, pid, (void*)vm_addr, NULL, 0);
350             if (errno)
351             {
352                 error.SetErrorToErrno();
353                 if (log)
354                     ProcessPOSIXLog::DecNestLevel();
355                 return bytes_read;
356             }
357 
358             remainder = size - bytes_read;
359             remainder = remainder > word_size ? word_size : remainder;
360 
361             // Copy the data into our buffer
362             for (unsigned i = 0; i < remainder; ++i)
363                 dst[i] = ((data >> i*8) & 0xFF);
364 
365             if (log && ProcessPOSIXLog::AtTopNestLevel() &&
366                     (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
367                             (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
368                                     size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
369             {
370                 uintptr_t print_dst = 0;
371                 // Format bytes from data by moving into print_dst for log output
372                 for (unsigned i = 0; i < remainder; ++i)
373                     print_dst |= (((data >> i*8) & 0xFF) << i*8);
374                 log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
375                         (void*)vm_addr, print_dst, (unsigned long)data);
376             }
377 
378             vm_addr += word_size;
379             dst += word_size;
380         }
381 
382         if (log)
383             ProcessPOSIXLog::DecNestLevel();
384         return bytes_read;
385     }
386 
387     static lldb::addr_t
388     DoWriteMemory(
389         lldb::pid_t pid,
390         lldb::addr_t vm_addr,
391         const void *buf,
392         lldb::addr_t size,
393         Error &error)
394     {
395         // ptrace word size is determined by the host, not the child
396         static const unsigned word_size = sizeof(void*);
397         const unsigned char *src = static_cast<const unsigned char*>(buf);
398         lldb::addr_t bytes_written = 0;
399         lldb::addr_t remainder;
400 
401         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
402         if (log)
403             ProcessPOSIXLog::IncNestLevel();
404         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
405             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %u, %p, %p, %" PRIu64 ")", __FUNCTION__,
406                     pid, word_size, (void*)vm_addr, buf, size);
407 
408         for (bytes_written = 0; bytes_written < size; bytes_written += remainder)
409         {
410             remainder = size - bytes_written;
411             remainder = remainder > word_size ? word_size : remainder;
412 
413             if (remainder == word_size)
414             {
415                 unsigned long data = 0;
416                 assert(sizeof(data) >= word_size);
417                 for (unsigned i = 0; i < word_size; ++i)
418                     data |= (unsigned long)src[i] << i*8;
419 
420                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
421                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
422                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
423                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
424                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
425                             (void*)vm_addr, *(unsigned long*)src, data);
426 
427                 if (PTRACE(PTRACE_POKEDATA, pid, (void*)vm_addr, (void*)data, 0))
428                 {
429                     error.SetErrorToErrno();
430                     if (log)
431                         ProcessPOSIXLog::DecNestLevel();
432                     return bytes_written;
433                 }
434             }
435             else
436             {
437                 unsigned char buff[8];
438                 if (DoReadMemory(pid, vm_addr,
439                                 buff, word_size, error) != word_size)
440                 {
441                     if (log)
442                         ProcessPOSIXLog::DecNestLevel();
443                     return bytes_written;
444                 }
445 
446                 memcpy(buff, src, remainder);
447 
448                 if (DoWriteMemory(pid, vm_addr,
449                                 buff, word_size, error) != word_size)
450                 {
451                     if (log)
452                         ProcessPOSIXLog::DecNestLevel();
453                     return bytes_written;
454                 }
455 
456                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
457                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
458                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
459                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
460                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
461                             (void*)vm_addr, *(unsigned long*)src, *(unsigned long*)buff);
462             }
463 
464             vm_addr += word_size;
465             src += word_size;
466         }
467         if (log)
468             ProcessPOSIXLog::DecNestLevel();
469         return bytes_written;
470     }
471 
472     //------------------------------------------------------------------------------
473     /// @class Operation
474     /// @brief Represents a NativeProcessLinux operation.
475     ///
476     /// Under Linux, it is not possible to ptrace() from any other thread but the
477     /// one that spawned or attached to the process from the start.  Therefore, when
478     /// a NativeProcessLinux is asked to deliver or change the state of an inferior
479     /// process the operation must be "funneled" to a specific thread to perform the
480     /// task.  The Operation class provides an abstract base for all services the
481     /// NativeProcessLinux must perform via the single virtual function Execute, thus
482     /// encapsulating the code that needs to run in the privileged context.
483     class Operation
484     {
485     public:
486         Operation () : m_error() { }
487 
488         virtual
489         ~Operation() {}
490 
491         virtual void
492         Execute (NativeProcessLinux *process) = 0;
493 
494         const Error &
495         GetError () const { return m_error; }
496 
497     protected:
498         Error m_error;
499     };
500 
501     //------------------------------------------------------------------------------
502     /// @class ReadOperation
503     /// @brief Implements NativeProcessLinux::ReadMemory.
504     class ReadOperation : public Operation
505     {
506     public:
507         ReadOperation (
508             lldb::addr_t addr,
509             void *buff,
510             lldb::addr_t size,
511             lldb::addr_t &result) :
512             Operation (),
513             m_addr (addr),
514             m_buff (buff),
515             m_size (size),
516             m_result (result)
517             {
518             }
519 
520         void Execute (NativeProcessLinux *process) override;
521 
522     private:
523         lldb::addr_t m_addr;
524         void *m_buff;
525         lldb::addr_t m_size;
526         lldb::addr_t &m_result;
527     };
528 
529     void
530     ReadOperation::Execute (NativeProcessLinux *process)
531     {
532         m_result = DoReadMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
533     }
534 
535     //------------------------------------------------------------------------------
536     /// @class WriteOperation
537     /// @brief Implements NativeProcessLinux::WriteMemory.
538     class WriteOperation : public Operation
539     {
540     public:
541         WriteOperation (
542             lldb::addr_t addr,
543             const void *buff,
544             lldb::addr_t size,
545             lldb::addr_t &result) :
546             Operation (),
547             m_addr (addr),
548             m_buff (buff),
549             m_size (size),
550             m_result (result)
551             {
552             }
553 
554         void Execute (NativeProcessLinux *process) override;
555 
556     private:
557         lldb::addr_t m_addr;
558         const void *m_buff;
559         lldb::addr_t m_size;
560         lldb::addr_t &m_result;
561     };
562 
563     void
564     WriteOperation::Execute(NativeProcessLinux *process)
565     {
566         m_result = DoWriteMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
567     }
568 
569     //------------------------------------------------------------------------------
570     /// @class ReadRegOperation
571     /// @brief Implements NativeProcessLinux::ReadRegisterValue.
572     class ReadRegOperation : public Operation
573     {
574     public:
575         ReadRegOperation(lldb::tid_t tid, uint32_t offset, const char *reg_name,
576                 RegisterValue &value, bool &result)
577             : m_tid(tid), m_offset(static_cast<uintptr_t> (offset)), m_reg_name(reg_name),
578               m_value(value), m_result(result)
579             { }
580 
581         void Execute(NativeProcessLinux *monitor);
582 
583     private:
584         lldb::tid_t m_tid;
585         uintptr_t m_offset;
586         const char *m_reg_name;
587         RegisterValue &m_value;
588         bool &m_result;
589     };
590 
591     void
592     ReadRegOperation::Execute(NativeProcessLinux *monitor)
593     {
594         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
595 
596         // Set errno to zero so that we can detect a failed peek.
597         errno = 0;
598         lldb::addr_t data = PTRACE(PTRACE_PEEKUSER, m_tid, (void*)m_offset, NULL, 0);
599         if (errno)
600             m_result = false;
601         else
602         {
603             m_value = data;
604             m_result = true;
605         }
606         if (log)
607             log->Printf ("NativeProcessLinux::%s() reg %s: 0x%" PRIx64, __FUNCTION__,
608                     m_reg_name, data);
609     }
610 
611     //------------------------------------------------------------------------------
612     /// @class WriteRegOperation
613     /// @brief Implements NativeProcessLinux::WriteRegisterValue.
614     class WriteRegOperation : public Operation
615     {
616     public:
617         WriteRegOperation(lldb::tid_t tid, unsigned offset, const char *reg_name,
618                 const RegisterValue &value, bool &result)
619             : m_tid(tid), m_offset(offset), m_reg_name(reg_name),
620               m_value(value), m_result(result)
621             { }
622 
623         void Execute(NativeProcessLinux *monitor);
624 
625     private:
626         lldb::tid_t m_tid;
627         uintptr_t m_offset;
628         const char *m_reg_name;
629         const RegisterValue &m_value;
630         bool &m_result;
631     };
632 
633     void
634     WriteRegOperation::Execute(NativeProcessLinux *monitor)
635     {
636         void* buf;
637         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
638 
639         buf = (void*) m_value.GetAsUInt64();
640 
641         if (log)
642             log->Printf ("NativeProcessLinux::%s() reg %s: %p", __FUNCTION__, m_reg_name, buf);
643         if (PTRACE(PTRACE_POKEUSER, m_tid, (void*)m_offset, buf, 0))
644             m_result = false;
645         else
646             m_result = true;
647     }
648 
649     //------------------------------------------------------------------------------
650     /// @class ReadGPROperation
651     /// @brief Implements NativeProcessLinux::ReadGPR.
652     class ReadGPROperation : public Operation
653     {
654     public:
655         ReadGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
656             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
657             { }
658 
659         void Execute(NativeProcessLinux *monitor);
660 
661     private:
662         lldb::tid_t m_tid;
663         void *m_buf;
664         size_t m_buf_size;
665         bool &m_result;
666     };
667 
668     void
669     ReadGPROperation::Execute(NativeProcessLinux *monitor)
670     {
671 #if defined (__arm64__) || defined (__aarch64__)
672         int regset = NT_PRSTATUS;
673         struct iovec ioVec;
674 
675         ioVec.iov_base = m_buf;
676         ioVec.iov_len = m_buf_size;
677         if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
678             m_result = false;
679         else
680             m_result = true;
681 #else
682         if (PTRACE(PTRACE_GETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
683             m_result = false;
684         else
685             m_result = true;
686 #endif
687     }
688 
689     //------------------------------------------------------------------------------
690     /// @class ReadFPROperation
691     /// @brief Implements NativeProcessLinux::ReadFPR.
692     class ReadFPROperation : public Operation
693     {
694     public:
695         ReadFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
696             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
697             { }
698 
699         void Execute(NativeProcessLinux *monitor);
700 
701     private:
702         lldb::tid_t m_tid;
703         void *m_buf;
704         size_t m_buf_size;
705         bool &m_result;
706     };
707 
708     void
709     ReadFPROperation::Execute(NativeProcessLinux *monitor)
710     {
711 #if defined (__arm64__) || defined (__aarch64__)
712         int regset = NT_FPREGSET;
713         struct iovec ioVec;
714 
715         ioVec.iov_base = m_buf;
716         ioVec.iov_len = m_buf_size;
717         if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
718             m_result = false;
719         else
720             m_result = true;
721 #else
722         if (PTRACE(PTRACE_GETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
723             m_result = false;
724         else
725             m_result = true;
726 #endif
727     }
728 
729     //------------------------------------------------------------------------------
730     /// @class ReadRegisterSetOperation
731     /// @brief Implements NativeProcessLinux::ReadRegisterSet.
732     class ReadRegisterSetOperation : public Operation
733     {
734     public:
735         ReadRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
736             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
737             { }
738 
739         void Execute(NativeProcessLinux *monitor);
740 
741     private:
742         lldb::tid_t m_tid;
743         void *m_buf;
744         size_t m_buf_size;
745         const unsigned int m_regset;
746         bool &m_result;
747     };
748 
749     void
750     ReadRegisterSetOperation::Execute(NativeProcessLinux *monitor)
751     {
752         if (PTRACE(PTRACE_GETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
753             m_result = false;
754         else
755             m_result = true;
756     }
757 
758     //------------------------------------------------------------------------------
759     /// @class WriteGPROperation
760     /// @brief Implements NativeProcessLinux::WriteGPR.
761     class WriteGPROperation : public Operation
762     {
763     public:
764         WriteGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
765             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
766             { }
767 
768         void Execute(NativeProcessLinux *monitor);
769 
770     private:
771         lldb::tid_t m_tid;
772         void *m_buf;
773         size_t m_buf_size;
774         bool &m_result;
775     };
776 
777     void
778     WriteGPROperation::Execute(NativeProcessLinux *monitor)
779     {
780 #if defined (__arm64__) || defined (__aarch64__)
781         int regset = NT_PRSTATUS;
782         struct iovec ioVec;
783 
784         ioVec.iov_base = m_buf;
785         ioVec.iov_len = m_buf_size;
786         if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
787             m_result = false;
788         else
789             m_result = true;
790 #else
791         if (PTRACE(PTRACE_SETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
792             m_result = false;
793         else
794             m_result = true;
795 #endif
796     }
797 
798     //------------------------------------------------------------------------------
799     /// @class WriteFPROperation
800     /// @brief Implements NativeProcessLinux::WriteFPR.
801     class WriteFPROperation : public Operation
802     {
803     public:
804         WriteFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
805             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
806             { }
807 
808         void Execute(NativeProcessLinux *monitor);
809 
810     private:
811         lldb::tid_t m_tid;
812         void *m_buf;
813         size_t m_buf_size;
814         bool &m_result;
815     };
816 
817     void
818     WriteFPROperation::Execute(NativeProcessLinux *monitor)
819     {
820 #if defined (__arm64__) || defined (__aarch64__)
821         int regset = NT_FPREGSET;
822         struct iovec ioVec;
823 
824         ioVec.iov_base = m_buf;
825         ioVec.iov_len = m_buf_size;
826         if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
827             m_result = false;
828         else
829             m_result = true;
830 #else
831         if (PTRACE(PTRACE_SETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
832             m_result = false;
833         else
834             m_result = true;
835 #endif
836     }
837 
838     //------------------------------------------------------------------------------
839     /// @class WriteRegisterSetOperation
840     /// @brief Implements NativeProcessLinux::WriteRegisterSet.
841     class WriteRegisterSetOperation : public Operation
842     {
843     public:
844         WriteRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
845             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
846             { }
847 
848         void Execute(NativeProcessLinux *monitor);
849 
850     private:
851         lldb::tid_t m_tid;
852         void *m_buf;
853         size_t m_buf_size;
854         const unsigned int m_regset;
855         bool &m_result;
856     };
857 
858     void
859     WriteRegisterSetOperation::Execute(NativeProcessLinux *monitor)
860     {
861         if (PTRACE(PTRACE_SETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
862             m_result = false;
863         else
864             m_result = true;
865     }
866 
867     //------------------------------------------------------------------------------
868     /// @class ResumeOperation
869     /// @brief Implements NativeProcessLinux::Resume.
870     class ResumeOperation : public Operation
871     {
872     public:
873         ResumeOperation(lldb::tid_t tid, uint32_t signo, bool &result) :
874             m_tid(tid), m_signo(signo), m_result(result) { }
875 
876         void Execute(NativeProcessLinux *monitor);
877 
878     private:
879         lldb::tid_t m_tid;
880         uint32_t m_signo;
881         bool &m_result;
882     };
883 
884     void
885     ResumeOperation::Execute(NativeProcessLinux *monitor)
886     {
887         intptr_t data = 0;
888 
889         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
890             data = m_signo;
891 
892         if (PTRACE(PTRACE_CONT, m_tid, NULL, (void*)data, 0))
893         {
894             Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
895 
896             if (log)
897                 log->Printf ("ResumeOperation (%"  PRIu64 ") failed: %s", m_tid, strerror(errno));
898             m_result = false;
899         }
900         else
901             m_result = true;
902     }
903 
904     //------------------------------------------------------------------------------
905     /// @class SingleStepOperation
906     /// @brief Implements NativeProcessLinux::SingleStep.
907     class SingleStepOperation : public Operation
908     {
909     public:
910         SingleStepOperation(lldb::tid_t tid, uint32_t signo, bool &result)
911             : m_tid(tid), m_signo(signo), m_result(result) { }
912 
913         void Execute(NativeProcessLinux *monitor);
914 
915     private:
916         lldb::tid_t m_tid;
917         uint32_t m_signo;
918         bool &m_result;
919     };
920 
921     void
922     SingleStepOperation::Execute(NativeProcessLinux *monitor)
923     {
924         intptr_t data = 0;
925 
926         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
927             data = m_signo;
928 
929         if (PTRACE(PTRACE_SINGLESTEP, m_tid, NULL, (void*)data, 0))
930             m_result = false;
931         else
932             m_result = true;
933     }
934 
935     //------------------------------------------------------------------------------
936     /// @class SiginfoOperation
937     /// @brief Implements NativeProcessLinux::GetSignalInfo.
938     class SiginfoOperation : public Operation
939     {
940     public:
941         SiginfoOperation(lldb::tid_t tid, void *info, bool &result, int &ptrace_err)
942             : m_tid(tid), m_info(info), m_result(result), m_err(ptrace_err) { }
943 
944         void Execute(NativeProcessLinux *monitor);
945 
946     private:
947         lldb::tid_t m_tid;
948         void *m_info;
949         bool &m_result;
950         int &m_err;
951     };
952 
953     void
954     SiginfoOperation::Execute(NativeProcessLinux *monitor)
955     {
956         if (PTRACE(PTRACE_GETSIGINFO, m_tid, NULL, m_info, 0)) {
957             m_result = false;
958             m_err = errno;
959         }
960         else
961             m_result = true;
962     }
963 
964     //------------------------------------------------------------------------------
965     /// @class EventMessageOperation
966     /// @brief Implements NativeProcessLinux::GetEventMessage.
967     class EventMessageOperation : public Operation
968     {
969     public:
970         EventMessageOperation(lldb::tid_t tid, unsigned long *message, bool &result)
971             : m_tid(tid), m_message(message), m_result(result) { }
972 
973         void Execute(NativeProcessLinux *monitor);
974 
975     private:
976         lldb::tid_t m_tid;
977         unsigned long *m_message;
978         bool &m_result;
979     };
980 
981     void
982     EventMessageOperation::Execute(NativeProcessLinux *monitor)
983     {
984         if (PTRACE(PTRACE_GETEVENTMSG, m_tid, NULL, m_message, 0))
985             m_result = false;
986         else
987             m_result = true;
988     }
989 
990     class DetachOperation : public Operation
991     {
992     public:
993         DetachOperation(lldb::tid_t tid, Error &result) : m_tid(tid), m_error(result) { }
994 
995         void Execute(NativeProcessLinux *monitor);
996 
997     private:
998         lldb::tid_t m_tid;
999         Error &m_error;
1000     };
1001 
1002     void
1003     DetachOperation::Execute(NativeProcessLinux *monitor)
1004     {
1005         if (ptrace(PT_DETACH, m_tid, NULL, 0) < 0)
1006             m_error.SetErrorToErrno();
1007     }
1008 
1009 }
1010 
1011 using namespace lldb_private;
1012 
1013 // Simple helper function to ensure flags are enabled on the given file
1014 // descriptor.
1015 static bool
1016 EnsureFDFlags(int fd, int flags, Error &error)
1017 {
1018     int status;
1019 
1020     if ((status = fcntl(fd, F_GETFL)) == -1)
1021     {
1022         error.SetErrorToErrno();
1023         return false;
1024     }
1025 
1026     if (fcntl(fd, F_SETFL, status | flags) == -1)
1027     {
1028         error.SetErrorToErrno();
1029         return false;
1030     }
1031 
1032     return true;
1033 }
1034 
1035 NativeProcessLinux::OperationArgs::OperationArgs(NativeProcessLinux *monitor)
1036     : m_monitor(monitor)
1037 {
1038     sem_init(&m_semaphore, 0, 0);
1039 }
1040 
1041 NativeProcessLinux::OperationArgs::~OperationArgs()
1042 {
1043     sem_destroy(&m_semaphore);
1044 }
1045 
1046 NativeProcessLinux::LaunchArgs::LaunchArgs(NativeProcessLinux *monitor,
1047                                        lldb_private::Module *module,
1048                                        char const **argv,
1049                                        char const **envp,
1050                                        const char *stdin_path,
1051                                        const char *stdout_path,
1052                                        const char *stderr_path,
1053                                        const char *working_dir,
1054                                        const lldb_private::ProcessLaunchInfo &launch_info)
1055     : OperationArgs(monitor),
1056       m_module(module),
1057       m_argv(argv),
1058       m_envp(envp),
1059       m_stdin_path(stdin_path),
1060       m_stdout_path(stdout_path),
1061       m_stderr_path(stderr_path),
1062       m_working_dir(working_dir),
1063       m_launch_info(launch_info)
1064 {
1065 }
1066 
1067 NativeProcessLinux::LaunchArgs::~LaunchArgs()
1068 { }
1069 
1070 NativeProcessLinux::AttachArgs::AttachArgs(NativeProcessLinux *monitor,
1071                                        lldb::pid_t pid)
1072     : OperationArgs(monitor), m_pid(pid) { }
1073 
1074 NativeProcessLinux::AttachArgs::~AttachArgs()
1075 { }
1076 
1077 // -----------------------------------------------------------------------------
1078 // Public Static Methods
1079 // -----------------------------------------------------------------------------
1080 
1081 lldb_private::Error
1082 NativeProcessLinux::LaunchProcess (
1083     lldb_private::Module *exe_module,
1084     lldb_private::ProcessLaunchInfo &launch_info,
1085     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1086     NativeProcessProtocolSP &native_process_sp)
1087 {
1088     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1089 
1090     Error error;
1091 
1092     // Verify the working directory is valid if one was specified.
1093     const char* working_dir = launch_info.GetWorkingDirectory ();
1094     if (working_dir)
1095     {
1096       FileSpec working_dir_fs (working_dir, true);
1097       if (!working_dir_fs || working_dir_fs.GetFileType () != FileSpec::eFileTypeDirectory)
1098       {
1099           error.SetErrorStringWithFormat ("No such file or directory: %s", working_dir);
1100           return error;
1101       }
1102     }
1103 
1104     const lldb_private::FileAction *file_action;
1105 
1106     // Default of NULL will mean to use existing open file descriptors.
1107     const char *stdin_path = NULL;
1108     const char *stdout_path = NULL;
1109     const char *stderr_path = NULL;
1110 
1111     file_action = launch_info.GetFileActionForFD (STDIN_FILENO);
1112     stdin_path = GetFilePath (file_action, stdin_path);
1113 
1114     file_action = launch_info.GetFileActionForFD (STDOUT_FILENO);
1115     stdout_path = GetFilePath (file_action, stdout_path);
1116 
1117     file_action = launch_info.GetFileActionForFD (STDERR_FILENO);
1118     stderr_path = GetFilePath (file_action, stderr_path);
1119 
1120     // Create the NativeProcessLinux in launch mode.
1121     native_process_sp.reset (new NativeProcessLinux ());
1122 
1123     if (log)
1124     {
1125         int i = 0;
1126         for (const char **args = launch_info.GetArguments ().GetConstArgumentVector (); *args; ++args, ++i)
1127         {
1128             log->Printf ("NativeProcessLinux::%s arg %d: \"%s\"", __FUNCTION__, i, *args ? *args : "nullptr");
1129             ++i;
1130         }
1131     }
1132 
1133     if (!native_process_sp->RegisterNativeDelegate (native_delegate))
1134     {
1135         native_process_sp.reset ();
1136         error.SetErrorStringWithFormat ("failed to register the native delegate");
1137         return error;
1138     }
1139 
1140     reinterpret_cast<NativeProcessLinux*> (native_process_sp.get ())->LaunchInferior (
1141             exe_module,
1142             launch_info.GetArguments ().GetConstArgumentVector (),
1143             launch_info.GetEnvironmentEntries ().GetConstArgumentVector (),
1144             stdin_path,
1145             stdout_path,
1146             stderr_path,
1147             working_dir,
1148             launch_info,
1149             error);
1150 
1151     if (error.Fail ())
1152     {
1153         native_process_sp.reset ();
1154         if (log)
1155             log->Printf ("NativeProcessLinux::%s failed to launch process: %s", __FUNCTION__, error.AsCString ());
1156         return error;
1157     }
1158 
1159     launch_info.SetProcessID (native_process_sp->GetID ());
1160 
1161     return error;
1162 }
1163 
1164 lldb_private::Error
1165 NativeProcessLinux::AttachToProcess (
1166     lldb::pid_t pid,
1167     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1168     NativeProcessProtocolSP &native_process_sp)
1169 {
1170     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1171     if (log && log->GetMask ().Test (POSIX_LOG_VERBOSE))
1172         log->Printf ("NativeProcessLinux::%s(pid = %" PRIi64 ")", __FUNCTION__, pid);
1173 
1174     // Grab the current platform architecture.  This should be Linux,
1175     // since this code is only intended to run on a Linux host.
1176     PlatformSP platform_sp (Platform::GetDefaultPlatform ());
1177     if (!platform_sp)
1178         return Error("failed to get a valid default platform");
1179 
1180     // Retrieve the architecture for the running process.
1181     ArchSpec process_arch;
1182     Error error = ResolveProcessArchitecture (pid, *platform_sp.get (), process_arch);
1183     if (!error.Success ())
1184         return error;
1185 
1186     native_process_sp.reset (new NativeProcessLinux ());
1187 
1188     if (!native_process_sp->RegisterNativeDelegate (native_delegate))
1189     {
1190         native_process_sp.reset (new NativeProcessLinux ());
1191         error.SetErrorStringWithFormat ("failed to register the native delegate");
1192         return error;
1193     }
1194 
1195     reinterpret_cast<NativeProcessLinux*> (native_process_sp.get ())->AttachToInferior (pid, error);
1196     if (!error.Success ())
1197     {
1198         native_process_sp.reset ();
1199         return error;
1200     }
1201 
1202     return error;
1203 }
1204 
1205 // -----------------------------------------------------------------------------
1206 // Public Instance Methods
1207 // -----------------------------------------------------------------------------
1208 
1209 NativeProcessLinux::NativeProcessLinux () :
1210     NativeProcessProtocol (LLDB_INVALID_PROCESS_ID),
1211     m_arch (),
1212     m_operation_thread (LLDB_INVALID_HOST_THREAD),
1213     m_monitor_thread (LLDB_INVALID_HOST_THREAD),
1214     m_operation (nullptr),
1215     m_operation_mutex (),
1216     m_operation_pending (),
1217     m_operation_done (),
1218     m_wait_for_stop_tids (),
1219     m_wait_for_stop_tids_mutex (),
1220     m_supports_mem_region (eLazyBoolCalculate),
1221     m_mem_region_cache (),
1222     m_mem_region_cache_mutex ()
1223 {
1224 }
1225 
1226 //------------------------------------------------------------------------------
1227 /// The basic design of the NativeProcessLinux is built around two threads.
1228 ///
1229 /// One thread (@see SignalThread) simply blocks on a call to waitpid() looking
1230 /// for changes in the debugee state.  When a change is detected a
1231 /// ProcessMessage is sent to the associated ProcessLinux instance.  This thread
1232 /// "drives" state changes in the debugger.
1233 ///
1234 /// The second thread (@see OperationThread) is responsible for two things 1)
1235 /// launching or attaching to the inferior process, and then 2) servicing
1236 /// operations such as register reads/writes, stepping, etc.  See the comments
1237 /// on the Operation class for more info as to why this is needed.
1238 void
1239 NativeProcessLinux::LaunchInferior (
1240     Module *module,
1241     const char *argv[],
1242     const char *envp[],
1243     const char *stdin_path,
1244     const char *stdout_path,
1245     const char *stderr_path,
1246     const char *working_dir,
1247     const lldb_private::ProcessLaunchInfo &launch_info,
1248     lldb_private::Error &error)
1249 {
1250     if (module)
1251         m_arch = module->GetArchitecture ();
1252 
1253     SetState(eStateLaunching);
1254 
1255     std::unique_ptr<LaunchArgs> args(
1256         new LaunchArgs(
1257             this, module, argv, envp,
1258             stdin_path, stdout_path, stderr_path,
1259             working_dir, launch_info));
1260 
1261     sem_init(&m_operation_pending, 0, 0);
1262     sem_init(&m_operation_done, 0, 0);
1263 
1264     StartLaunchOpThread(args.get(), error);
1265     if (!error.Success())
1266         return;
1267 
1268 WAIT_AGAIN:
1269     // Wait for the operation thread to initialize.
1270     if (sem_wait(&args->m_semaphore))
1271     {
1272         if (errno == EINTR)
1273             goto WAIT_AGAIN;
1274         else
1275         {
1276             error.SetErrorToErrno();
1277             return;
1278         }
1279     }
1280 
1281     // Check that the launch was a success.
1282     if (!args->m_error.Success())
1283     {
1284         StopOpThread();
1285         error = args->m_error;
1286         return;
1287     }
1288 
1289     // Finally, start monitoring the child process for change in state.
1290     m_monitor_thread = Host::StartMonitoringChildProcess(
1291         NativeProcessLinux::MonitorCallback, this, GetID(), true);
1292     if (!IS_VALID_LLDB_HOST_THREAD(m_monitor_thread))
1293     {
1294         error.SetErrorToGenericError();
1295         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1296         return;
1297     }
1298 }
1299 
1300 void
1301 NativeProcessLinux::AttachToInferior (lldb::pid_t pid, lldb_private::Error &error)
1302 {
1303     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1304     if (log)
1305         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ")", __FUNCTION__, pid);
1306 
1307     // We can use the Host for everything except the ResolveExecutable portion.
1308     PlatformSP platform_sp = Platform::GetDefaultPlatform ();
1309     if (!platform_sp)
1310     {
1311         if (log)
1312             log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 "): no default platform set", __FUNCTION__, pid);
1313         error.SetErrorString ("no default platform available");
1314     }
1315 
1316     // Gather info about the process.
1317     ProcessInstanceInfo process_info;
1318     platform_sp->GetProcessInfo (pid, process_info);
1319 
1320     // Resolve the executable module
1321     ModuleSP exe_module_sp;
1322     FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths());
1323 
1324     error = platform_sp->ResolveExecutable(process_info.GetExecutableFile(), HostInfo::GetArchitecture(), exe_module_sp,
1325                                            executable_search_paths.GetSize() ? &executable_search_paths : NULL);
1326     if (!error.Success())
1327         return;
1328 
1329     // Set the architecture to the exe architecture.
1330     m_arch = exe_module_sp->GetArchitecture();
1331     if (log)
1332         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ") detected architecture %s", __FUNCTION__, pid, m_arch.GetArchitectureName ());
1333 
1334     m_pid = pid;
1335     SetState(eStateAttaching);
1336 
1337     sem_init (&m_operation_pending, 0, 0);
1338     sem_init (&m_operation_done, 0, 0);
1339 
1340     std::unique_ptr<AttachArgs> args (new AttachArgs (this, pid));
1341 
1342     StartAttachOpThread(args.get (), error);
1343     if (!error.Success ())
1344         return;
1345 
1346 WAIT_AGAIN:
1347     // Wait for the operation thread to initialize.
1348     if (sem_wait (&args->m_semaphore))
1349     {
1350         if (errno == EINTR)
1351             goto WAIT_AGAIN;
1352         else
1353         {
1354             error.SetErrorToErrno ();
1355             return;
1356         }
1357     }
1358 
1359     // Check that the attach was a success.
1360     if (!args->m_error.Success ())
1361     {
1362         StopOpThread ();
1363         error = args->m_error;
1364         return;
1365     }
1366 
1367     // Finally, start monitoring the child process for change in state.
1368     m_monitor_thread = Host::StartMonitoringChildProcess (
1369         NativeProcessLinux::MonitorCallback, this, GetID (), true);
1370     if (!IS_VALID_LLDB_HOST_THREAD (m_monitor_thread))
1371     {
1372         error.SetErrorToGenericError ();
1373         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1374         return;
1375     }
1376 }
1377 
1378 NativeProcessLinux::~NativeProcessLinux()
1379 {
1380     StopMonitor();
1381 }
1382 
1383 //------------------------------------------------------------------------------
1384 // Thread setup and tear down.
1385 
1386 void
1387 NativeProcessLinux::StartLaunchOpThread(LaunchArgs *args, Error &error)
1388 {
1389     static const char *g_thread_name = "lldb.process.nativelinux.operation";
1390 
1391     if (IS_VALID_LLDB_HOST_THREAD (m_operation_thread))
1392         return;
1393 
1394     m_operation_thread =
1395         Host::ThreadCreate (g_thread_name, LaunchOpThread, args, &error);
1396 }
1397 
1398 void *
1399 NativeProcessLinux::LaunchOpThread(void *arg)
1400 {
1401     LaunchArgs *args = static_cast<LaunchArgs*>(arg);
1402 
1403     if (!Launch(args)) {
1404         sem_post(&args->m_semaphore);
1405         return NULL;
1406     }
1407 
1408     ServeOperation(args);
1409     return NULL;
1410 }
1411 
1412 bool
1413 NativeProcessLinux::Launch(LaunchArgs *args)
1414 {
1415     assert (args && "null args");
1416     if (!args)
1417         return false;
1418 
1419     NativeProcessLinux *monitor = args->m_monitor;
1420     assert (monitor && "monitor is NULL");
1421     if (!monitor)
1422         return false;
1423 
1424     const char **argv = args->m_argv;
1425     const char **envp = args->m_envp;
1426     const char *stdin_path = args->m_stdin_path;
1427     const char *stdout_path = args->m_stdout_path;
1428     const char *stderr_path = args->m_stderr_path;
1429     const char *working_dir = args->m_working_dir;
1430 
1431     lldb_utility::PseudoTerminal terminal;
1432     const size_t err_len = 1024;
1433     char err_str[err_len];
1434     lldb::pid_t pid;
1435     NativeThreadProtocolSP thread_sp;
1436 
1437     lldb::ThreadSP inferior;
1438     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1439 
1440     // Propagate the environment if one is not supplied.
1441     if (envp == NULL || envp[0] == NULL)
1442         envp = const_cast<const char **>(environ);
1443 
1444     if ((pid = terminal.Fork(err_str, err_len)) == static_cast<lldb::pid_t> (-1))
1445     {
1446         args->m_error.SetErrorToGenericError();
1447         args->m_error.SetErrorString("Process fork failed.");
1448         goto FINISH;
1449     }
1450 
1451     // Recognized child exit status codes.
1452     enum {
1453         ePtraceFailed = 1,
1454         eDupStdinFailed,
1455         eDupStdoutFailed,
1456         eDupStderrFailed,
1457         eChdirFailed,
1458         eExecFailed,
1459         eSetGidFailed
1460     };
1461 
1462     // Child process.
1463     if (pid == 0)
1464     {
1465         if (log)
1466             log->Printf ("NativeProcessLinux::%s inferior process preparing to fork", __FUNCTION__);
1467 
1468         // Trace this process.
1469         if (log)
1470             log->Printf ("NativeProcessLinux::%s inferior process issuing PTRACE_TRACEME", __FUNCTION__);
1471 
1472         if (PTRACE(PTRACE_TRACEME, 0, NULL, NULL, 0) < 0)
1473         {
1474             if (log)
1475                 log->Printf ("NativeProcessLinux::%s inferior process PTRACE_TRACEME failed", __FUNCTION__);
1476             exit(ePtraceFailed);
1477         }
1478 
1479         // Do not inherit setgid powers.
1480         if (log)
1481             log->Printf ("NativeProcessLinux::%s inferior process resetting gid", __FUNCTION__);
1482 
1483         if (setgid(getgid()) != 0)
1484         {
1485             if (log)
1486                 log->Printf ("NativeProcessLinux::%s inferior process setgid() failed", __FUNCTION__);
1487             exit(eSetGidFailed);
1488         }
1489 
1490         // Attempt to have our own process group.
1491         // TODO verify if we really want this.
1492         if (log)
1493             log->Printf ("NativeProcessLinux::%s inferior process resetting process group", __FUNCTION__);
1494 
1495         if (setpgid(0, 0) != 0)
1496         {
1497             if (log)
1498             {
1499                 const int error_code = errno;
1500                 log->Printf ("NativeProcessLinux::%s inferior setpgid() failed, errno=%d (%s), continuing with existing proccess group %" PRIu64,
1501                         __FUNCTION__,
1502                         error_code,
1503                         strerror (error_code),
1504                         static_cast<lldb::pid_t> (getpgid (0)));
1505             }
1506             // Don't allow this to prevent an inferior exec.
1507         }
1508 
1509         // Dup file descriptors if needed.
1510         //
1511         // FIXME: If two or more of the paths are the same we needlessly open
1512         // the same file multiple times.
1513         if (stdin_path != NULL && stdin_path[0])
1514             if (!DupDescriptor(stdin_path, STDIN_FILENO, O_RDONLY))
1515                 exit(eDupStdinFailed);
1516 
1517         if (stdout_path != NULL && stdout_path[0])
1518             if (!DupDescriptor(stdout_path, STDOUT_FILENO, O_WRONLY | O_CREAT))
1519                 exit(eDupStdoutFailed);
1520 
1521         if (stderr_path != NULL && stderr_path[0])
1522             if (!DupDescriptor(stderr_path, STDERR_FILENO, O_WRONLY | O_CREAT))
1523                 exit(eDupStderrFailed);
1524 
1525         // Change working directory
1526         if (working_dir != NULL && working_dir[0])
1527           if (0 != ::chdir(working_dir))
1528               exit(eChdirFailed);
1529 
1530         // Disable ASLR if requested.
1531         if (args->m_launch_info.GetFlags ().Test (lldb::eLaunchFlagDisableASLR))
1532         {
1533             const int old_personality = personality (LLDB_PERSONALITY_GET_CURRENT_SETTINGS);
1534             if (old_personality == -1)
1535             {
1536                 if (log)
1537                     log->Printf ("NativeProcessLinux::%s retrieval of Linux personality () failed: %s. Cannot disable ASLR.", __FUNCTION__, strerror (errno));
1538             }
1539             else
1540             {
1541                 const int new_personality = personality (ADDR_NO_RANDOMIZE | old_personality);
1542                 if (new_personality == -1)
1543                 {
1544                     if (log)
1545                         log->Printf ("NativeProcessLinux::%s setting of Linux personality () to disable ASLR failed, ignoring: %s", __FUNCTION__, strerror (errno));
1546 
1547                 }
1548                 else
1549                 {
1550                     if (log)
1551                         log->Printf ("NativeProcessLinux::%s disbling ASLR: SUCCESS", __FUNCTION__);
1552 
1553                 }
1554             }
1555         }
1556 
1557         // Execute.  We should never return.
1558         execve(argv[0],
1559                const_cast<char *const *>(argv),
1560                const_cast<char *const *>(envp));
1561         exit(eExecFailed);
1562     }
1563 
1564     // Wait for the child process to trap on its call to execve.
1565     ::pid_t wpid;
1566     int status;
1567     if ((wpid = waitpid(pid, &status, 0)) < 0)
1568     {
1569         args->m_error.SetErrorToErrno();
1570 
1571         if (log)
1572             log->Printf ("NativeProcessLinux::%s waitpid for inferior failed with %s", __FUNCTION__, args->m_error.AsCString ());
1573 
1574         // Mark the inferior as invalid.
1575         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1576         monitor->SetState (StateType::eStateInvalid);
1577 
1578         goto FINISH;
1579     }
1580     else if (WIFEXITED(status))
1581     {
1582         // open, dup or execve likely failed for some reason.
1583         args->m_error.SetErrorToGenericError();
1584         switch (WEXITSTATUS(status))
1585         {
1586             case ePtraceFailed:
1587                 args->m_error.SetErrorString("Child ptrace failed.");
1588                 break;
1589             case eDupStdinFailed:
1590                 args->m_error.SetErrorString("Child open stdin failed.");
1591                 break;
1592             case eDupStdoutFailed:
1593                 args->m_error.SetErrorString("Child open stdout failed.");
1594                 break;
1595             case eDupStderrFailed:
1596                 args->m_error.SetErrorString("Child open stderr failed.");
1597                 break;
1598             case eChdirFailed:
1599                 args->m_error.SetErrorString("Child failed to set working directory.");
1600                 break;
1601             case eExecFailed:
1602                 args->m_error.SetErrorString("Child exec failed.");
1603                 break;
1604             case eSetGidFailed:
1605                 args->m_error.SetErrorString("Child setgid failed.");
1606                 break;
1607             default:
1608                 args->m_error.SetErrorString("Child returned unknown exit status.");
1609                 break;
1610         }
1611 
1612         if (log)
1613         {
1614             log->Printf ("NativeProcessLinux::%s inferior exited with status %d before issuing a STOP",
1615                     __FUNCTION__,
1616                     WEXITSTATUS(status));
1617         }
1618 
1619         // Mark the inferior as invalid.
1620         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1621         monitor->SetState (StateType::eStateInvalid);
1622 
1623         goto FINISH;
1624     }
1625     assert(WIFSTOPPED(status) && (wpid == static_cast< ::pid_t> (pid)) &&
1626            "Could not sync with inferior process.");
1627 
1628     if (log)
1629         log->Printf ("NativeProcessLinux::%s inferior started, now in stopped state", __FUNCTION__);
1630 
1631     if (!SetDefaultPtraceOpts(pid))
1632     {
1633         args->m_error.SetErrorToErrno();
1634         if (log)
1635             log->Printf ("NativeProcessLinux::%s inferior failed to set default ptrace options: %s",
1636                     __FUNCTION__,
1637                     args->m_error.AsCString ());
1638 
1639         // Mark the inferior as invalid.
1640         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1641         monitor->SetState (StateType::eStateInvalid);
1642 
1643         goto FINISH;
1644     }
1645 
1646     // Release the master terminal descriptor and pass it off to the
1647     // NativeProcessLinux instance.  Similarly stash the inferior pid.
1648     monitor->m_terminal_fd = terminal.ReleaseMasterFileDescriptor();
1649     monitor->m_pid = pid;
1650 
1651     // Set the terminal fd to be in non blocking mode (it simplifies the
1652     // implementation of ProcessLinux::GetSTDOUT to have a non-blocking
1653     // descriptor to read from).
1654     if (!EnsureFDFlags(monitor->m_terminal_fd, O_NONBLOCK, args->m_error))
1655     {
1656         if (log)
1657             log->Printf ("NativeProcessLinux::%s inferior EnsureFDFlags failed for ensuring terminal O_NONBLOCK setting: %s",
1658                     __FUNCTION__,
1659                     args->m_error.AsCString ());
1660 
1661         // Mark the inferior as invalid.
1662         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1663         monitor->SetState (StateType::eStateInvalid);
1664 
1665         goto FINISH;
1666     }
1667 
1668     if (log)
1669         log->Printf ("NativeProcessLinux::%s() adding pid = %" PRIu64, __FUNCTION__, pid);
1670 
1671     thread_sp = monitor->AddThread (static_cast<lldb::tid_t> (pid));
1672     assert (thread_sp && "AddThread() returned a nullptr thread");
1673     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1674     monitor->SetCurrentThreadID (thread_sp->GetID ());
1675 
1676     // Let our process instance know the thread has stopped.
1677     monitor->SetState (StateType::eStateStopped);
1678 
1679 FINISH:
1680     if (log)
1681     {
1682         if (args->m_error.Success ())
1683         {
1684             log->Printf ("NativeProcessLinux::%s inferior launching succeeded", __FUNCTION__);
1685         }
1686         else
1687         {
1688             log->Printf ("NativeProcessLinux::%s inferior launching failed: %s",
1689                 __FUNCTION__,
1690                 args->m_error.AsCString ());
1691         }
1692     }
1693     return args->m_error.Success();
1694 }
1695 
1696 void
1697 NativeProcessLinux::StartAttachOpThread(AttachArgs *args, lldb_private::Error &error)
1698 {
1699     static const char *g_thread_name = "lldb.process.linux.operation";
1700 
1701     if (IS_VALID_LLDB_HOST_THREAD(m_operation_thread))
1702         return;
1703 
1704     m_operation_thread =
1705         Host::ThreadCreate(g_thread_name, AttachOpThread, args, &error);
1706 }
1707 
1708 void *
1709 NativeProcessLinux::AttachOpThread(void *arg)
1710 {
1711     AttachArgs *args = static_cast<AttachArgs*>(arg);
1712 
1713     if (!Attach(args)) {
1714         sem_post(&args->m_semaphore);
1715         return NULL;
1716     }
1717 
1718     ServeOperation(args);
1719     return NULL;
1720 }
1721 
1722 bool
1723 NativeProcessLinux::Attach(AttachArgs *args)
1724 {
1725     lldb::pid_t pid = args->m_pid;
1726 
1727     NativeProcessLinux *monitor = args->m_monitor;
1728     lldb::ThreadSP inferior;
1729     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1730 
1731     // Use a map to keep track of the threads which we have attached/need to attach.
1732     Host::TidMap tids_to_attach;
1733     if (pid <= 1)
1734     {
1735         args->m_error.SetErrorToGenericError();
1736         args->m_error.SetErrorString("Attaching to process 1 is not allowed.");
1737         goto FINISH;
1738     }
1739 
1740     while (Host::FindProcessThreads(pid, tids_to_attach))
1741     {
1742         for (Host::TidMap::iterator it = tids_to_attach.begin();
1743              it != tids_to_attach.end();)
1744         {
1745             if (it->second == false)
1746             {
1747                 lldb::tid_t tid = it->first;
1748 
1749                 // Attach to the requested process.
1750                 // An attach will cause the thread to stop with a SIGSTOP.
1751                 if (PTRACE(PTRACE_ATTACH, tid, NULL, NULL, 0) < 0)
1752                 {
1753                     // No such thread. The thread may have exited.
1754                     // More error handling may be needed.
1755                     if (errno == ESRCH)
1756                     {
1757                         it = tids_to_attach.erase(it);
1758                         continue;
1759                     }
1760                     else
1761                     {
1762                         args->m_error.SetErrorToErrno();
1763                         goto FINISH;
1764                     }
1765                 }
1766 
1767                 int status;
1768                 // Need to use __WALL otherwise we receive an error with errno=ECHLD
1769                 // At this point we should have a thread stopped if waitpid succeeds.
1770                 if ((status = waitpid(tid, NULL, __WALL)) < 0)
1771                 {
1772                     // No such thread. The thread may have exited.
1773                     // More error handling may be needed.
1774                     if (errno == ESRCH)
1775                     {
1776                         it = tids_to_attach.erase(it);
1777                         continue;
1778                     }
1779                     else
1780                     {
1781                         args->m_error.SetErrorToErrno();
1782                         goto FINISH;
1783                     }
1784                 }
1785 
1786                 if (!SetDefaultPtraceOpts(tid))
1787                 {
1788                     args->m_error.SetErrorToErrno();
1789                     goto FINISH;
1790                 }
1791 
1792 
1793                 if (log)
1794                     log->Printf ("NativeProcessLinux::%s() adding tid = %" PRIu64, __FUNCTION__, tid);
1795 
1796                 it->second = true;
1797 
1798                 // Create the thread, mark it as stopped.
1799                 NativeThreadProtocolSP thread_sp (monitor->AddThread (static_cast<lldb::tid_t> (tid)));
1800                 assert (thread_sp && "AddThread() returned a nullptr");
1801                 reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1802                 monitor->SetCurrentThreadID (thread_sp->GetID ());
1803             }
1804 
1805             // move the loop forward
1806             ++it;
1807         }
1808     }
1809 
1810     if (tids_to_attach.size() > 0)
1811     {
1812         monitor->m_pid = pid;
1813         // Let our process instance know the thread has stopped.
1814         monitor->SetState (StateType::eStateStopped);
1815     }
1816     else
1817     {
1818         args->m_error.SetErrorToGenericError();
1819         args->m_error.SetErrorString("No such process.");
1820     }
1821 
1822  FINISH:
1823     return args->m_error.Success();
1824 }
1825 
1826 bool
1827 NativeProcessLinux::SetDefaultPtraceOpts(lldb::pid_t pid)
1828 {
1829     long ptrace_opts = 0;
1830 
1831     // Have the child raise an event on exit.  This is used to keep the child in
1832     // limbo until it is destroyed.
1833     ptrace_opts |= PTRACE_O_TRACEEXIT;
1834 
1835     // Have the tracer trace threads which spawn in the inferior process.
1836     // TODO: if we want to support tracing the inferiors' child, add the
1837     // appropriate ptrace flags here (PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)
1838     ptrace_opts |= PTRACE_O_TRACECLONE;
1839 
1840     // Have the tracer notify us before execve returns
1841     // (needed to disable legacy SIGTRAP generation)
1842     ptrace_opts |= PTRACE_O_TRACEEXEC;
1843 
1844     return PTRACE(PTRACE_SETOPTIONS, pid, NULL, (void*)ptrace_opts, 0) >= 0;
1845 }
1846 
1847 static ExitType convert_pid_status_to_exit_type (int status)
1848 {
1849     if (WIFEXITED (status))
1850         return ExitType::eExitTypeExit;
1851     else if (WIFSIGNALED (status))
1852         return ExitType::eExitTypeSignal;
1853     else if (WIFSTOPPED (status))
1854         return ExitType::eExitTypeStop;
1855     else
1856     {
1857         // We don't know what this is.
1858         return ExitType::eExitTypeInvalid;
1859     }
1860 }
1861 
1862 static int convert_pid_status_to_return_code (int status)
1863 {
1864     if (WIFEXITED (status))
1865         return WEXITSTATUS (status);
1866     else if (WIFSIGNALED (status))
1867         return WTERMSIG (status);
1868     else if (WIFSTOPPED (status))
1869         return WSTOPSIG (status);
1870     else
1871     {
1872         // We don't know what this is.
1873         return ExitType::eExitTypeInvalid;
1874     }
1875 }
1876 
1877 // Main process monitoring waitpid-loop handler.
1878 bool
1879 NativeProcessLinux::MonitorCallback(void *callback_baton,
1880                                 lldb::pid_t pid,
1881                                 bool exited,
1882                                 int signal,
1883                                 int status)
1884 {
1885     Log *log (GetLogIfAnyCategoriesSet (LIBLLDB_LOG_PROCESS));
1886 
1887     NativeProcessLinux *const process = static_cast<NativeProcessLinux*>(callback_baton);
1888     assert (process && "process is null");
1889     if (!process)
1890     {
1891         if (log)
1892             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " callback_baton was null, can't determine process to use", __FUNCTION__, pid);
1893         return true;
1894     }
1895 
1896     // Certain activities differ based on whether the pid is the tid of the main thread.
1897     const bool is_main_thread = (pid == process->GetID ());
1898 
1899     // Assume we keep monitoring by default.
1900     bool stop_monitoring = false;
1901 
1902     // Handle when the thread exits.
1903     if (exited)
1904     {
1905         if (log)
1906             log->Printf ("NativeProcessLinux::%s() got exit signal, tid = %"  PRIu64 " (%s main thread)", __FUNCTION__, pid, is_main_thread ? "is" : "is not");
1907 
1908         // This is a thread that exited.  Ensure we're not tracking it anymore.
1909         const bool thread_found = process->StopTrackingThread (pid);
1910 
1911         if (is_main_thread)
1912         {
1913             // We only set the exit status and notify the delegate if we haven't already set the process
1914             // state to an exited state.  We normally should have received a SIGTRAP | (PTRACE_EVENT_EXIT << 8)
1915             // for the main thread.
1916             const bool already_notified = (process->GetState() == StateType::eStateExited) | (process->GetState () == StateType::eStateCrashed);
1917             if (!already_notified)
1918             {
1919                 if (log)
1920                     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 ()));
1921                 // The main thread exited.  We're done monitoring.  Report to delegate.
1922                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
1923 
1924                 // Notify delegate that our process has exited.
1925                 process->SetState (StateType::eStateExited, true);
1926             }
1927             else
1928             {
1929                 if (log)
1930                     log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " main thread now exited (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
1931             }
1932             return true;
1933         }
1934         else
1935         {
1936             // Do we want to report to the delegate in this case?  I think not.  If this was an orderly
1937             // thread exit, we would already have received the SIGTRAP | (PTRACE_EVENT_EXIT << 8) signal,
1938             // and we would have done an all-stop then.
1939             if (log)
1940                 log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " handling non-main thread exit (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
1941 
1942             // Not the main thread, we keep going.
1943             return false;
1944         }
1945     }
1946 
1947     // Get details on the signal raised.
1948     siginfo_t info;
1949     int ptrace_err = 0;
1950 
1951     if (!process->GetSignalInfo (pid, &info, ptrace_err))
1952     {
1953         if (ptrace_err == EINVAL)
1954         {
1955             // This is the first part of the Linux ptrace group-stop mechanism.
1956             // (The other thing it can conceivably be is a call on a pid that no
1957             // longer exists for some reason).
1958             // The tracer (i.e. NativeProcessLinux) is expected to inject the signal
1959             // into the tracee (i.e. inferior) at this point.
1960             if (log)
1961                 log->Printf ("NativeProcessLinux::%s resuming from group-stop", __FUNCTION__);
1962 
1963             // The inferior process is in 'group-stop', so deliver the stopping signal.
1964             const bool signal_delivered = process->Resume (pid, info.si_signo);
1965             if (log)
1966                 log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " group-stop signal delivery of signal 0x%x (%s) - %s", __FUNCTION__, pid, info.si_signo, GetUnixSignals ().GetSignalAsCString (info.si_signo), signal_delivered ? "success" : "failed");
1967 
1968             if (signal_delivered)
1969             {
1970                 // All is well.
1971                 stop_monitoring = false;
1972             }
1973             else
1974             {
1975                 if (log)
1976                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " something looks horribly wrong - like the process we're monitoring died.  Stop monitoring it.", __FUNCTION__, pid);
1977 
1978                 // Stop monitoring now.
1979                 return true;
1980             }
1981         }
1982         else
1983         {
1984             // ptrace(GETSIGINFO) failed (but not due to group-stop).
1985 
1986             // A return value of ESRCH means the thread/process is no longer on the system,
1987             // so it was killed somehow outside of our control.  Either way, we can't do anything
1988             // with it anymore.
1989 
1990             // We stop monitoring if it was the main thread.
1991             stop_monitoring = is_main_thread;
1992 
1993             // Stop tracking the metadata for the thread since it's entirely off the system now.
1994             const bool thread_found = process->StopTrackingThread (pid);
1995 
1996             if (log)
1997                 log->Printf ("NativeProcessLinux::%s GetSignalInfo failed: %s, tid = %" PRIu64 ", signal = %d, status = %d (%s, %s, %s)",
1998                              __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");
1999 
2000             if (is_main_thread)
2001             {
2002                 // Notify the delegate - our process is not available but appears to have been killed outside
2003                 // our control.  Is eStateExited the right exit state in this case?
2004                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
2005                 process->SetState (StateType::eStateExited, true);
2006             }
2007             else
2008             {
2009                 // This thread was pulled out from underneath us.  Anything to do here? Do we want to do an all stop?
2010                 if (log)
2011                     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);
2012             }
2013         }
2014     }
2015     else
2016     {
2017         // We have retrieved the signal info.  Dispatch appropriately.
2018         if (info.si_signo == SIGTRAP)
2019             process->MonitorSIGTRAP(&info, pid);
2020         else
2021             process->MonitorSignal(&info, pid, exited);
2022 
2023         stop_monitoring = false;
2024     }
2025 
2026     return stop_monitoring;
2027 }
2028 
2029 void
2030 NativeProcessLinux::MonitorSIGTRAP(const siginfo_t *info, lldb::pid_t pid)
2031 {
2032     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2033     const bool is_main_thread = (pid == GetID ());
2034 
2035     assert(info && info->si_signo == SIGTRAP && "Unexpected child signal!");
2036     if (!info)
2037         return;
2038 
2039     // See if we can find a thread for this signal.
2040     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2041     if (!thread_sp)
2042     {
2043         if (log)
2044             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2045     }
2046 
2047     switch (info->si_code)
2048     {
2049     // TODO: these two cases are required if we want to support tracing of the inferiors' children.  We'd need this to debug a monitor.
2050     // case (SIGTRAP | (PTRACE_EVENT_FORK << 8)):
2051     // case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):
2052 
2053     case (SIGTRAP | (PTRACE_EVENT_CLONE << 8)):
2054     {
2055         lldb::tid_t tid = LLDB_INVALID_THREAD_ID;
2056 
2057         unsigned long event_message = 0;
2058         if (GetEventMessage(pid, &event_message))
2059             tid = static_cast<lldb::tid_t> (event_message);
2060 
2061         if (log)
2062             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " received thread creation event for tid %" PRIu64, __FUNCTION__, pid, tid);
2063 
2064         // If we don't track the thread yet: create it, mark as stopped.
2065         // If we do track it, this is the wait we needed.  Now resume the new thread.
2066         // In all cases, resume the current (i.e. main process) thread.
2067         bool already_tracked = false;
2068         thread_sp = GetOrCreateThread (tid, already_tracked);
2069         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2070 
2071         // If the thread was already tracked, it means the created thread already received its SI_USER notification of creation.
2072         if (already_tracked)
2073         {
2074             // FIXME loops like we want to stop all theads here.
2075             // StopAllThreads
2076 
2077             // We can now resume the newly created thread since it is fully created.
2078             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2079             Resume (tid, LLDB_INVALID_SIGNAL_NUMBER);
2080         }
2081         else
2082         {
2083             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2084             // this thread is ready to go.
2085             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2086         }
2087 
2088         // In all cases, we can resume the main thread here.
2089         Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
2090         break;
2091     }
2092 
2093     case (SIGTRAP | (PTRACE_EVENT_EXEC << 8)):
2094     {
2095         NativeThreadProtocolSP main_thread_sp;
2096 
2097         if (log)
2098             log->Printf ("NativeProcessLinux::%s() received exec event, code = %d", __FUNCTION__, info->si_code ^ SIGTRAP);
2099 
2100         // Remove all but the main thread here.
2101         // FIXME check if we really need to do this - how does ptrace behave under exec when multiple threads were present
2102         // before the exec?  If we get all the detach signals right, we don't need to do this.  However, it makes it clearer
2103         // what we should really be tracking.
2104         {
2105             Mutex::Locker locker (m_threads_mutex);
2106 
2107             if (log)
2108                 log->Printf ("NativeProcessLinux::%s exec received, stop tracking all but main thread", __FUNCTION__);
2109 
2110             for (auto thread_sp : m_threads)
2111             {
2112                 const bool is_main_thread = thread_sp && thread_sp->GetID () == GetID ();
2113                 if (is_main_thread)
2114                 {
2115                     main_thread_sp = thread_sp;
2116                     if (log)
2117                         log->Printf ("NativeProcessLinux::%s found main thread with tid %" PRIu64 ", keeping", __FUNCTION__, main_thread_sp->GetID ());
2118                 }
2119                 else
2120                 {
2121                     if (log)
2122                         log->Printf ("NativeProcessLinux::%s discarding non-main-thread tid %" PRIu64 " due to exec", __FUNCTION__, thread_sp->GetID ());
2123                 }
2124             }
2125 
2126             m_threads.clear ();
2127 
2128             if (main_thread_sp)
2129             {
2130                 m_threads.push_back (main_thread_sp);
2131                 SetCurrentThreadID (main_thread_sp->GetID ());
2132                 reinterpret_cast<NativeThreadLinux*>(main_thread_sp.get())->SetStoppedByExec ();
2133             }
2134             else
2135             {
2136                 SetCurrentThreadID (LLDB_INVALID_THREAD_ID);
2137                 if (log)
2138                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 "no main thread found, discarded all threads, we're in a no-thread state!", __FUNCTION__, GetID ());
2139             }
2140         }
2141 
2142         // Let our delegate know we have just exec'd.
2143         NotifyDidExec ();
2144 
2145         // If we have a main thread, indicate we are stopped.
2146         assert (main_thread_sp && "exec called during ptraced process but no main thread metadata tracked");
2147         SetState (StateType::eStateStopped);
2148 
2149         break;
2150     }
2151 
2152     case (SIGTRAP | (PTRACE_EVENT_EXIT << 8)):
2153     {
2154         // The inferior process or one of its threads is about to exit.
2155         // Maintain the process or thread in a state of "limbo" until we are
2156         // explicitly commanded to detach, destroy, resume, etc.
2157         unsigned long data = 0;
2158         if (!GetEventMessage(pid, &data))
2159             data = -1;
2160 
2161         if (log)
2162         {
2163             log->Printf ("NativeProcessLinux::%s() received PTRACE_EVENT_EXIT, data = %lx (WIFEXITED=%s,WIFSIGNALED=%s), pid = %" PRIu64 " (%s)",
2164                          __FUNCTION__,
2165                          data, WIFEXITED (data) ? "true" : "false", WIFSIGNALED (data) ? "true" : "false",
2166                          pid,
2167                     is_main_thread ? "is main thread" : "not main thread");
2168         }
2169 
2170         // Set the thread to exited.
2171         if (thread_sp)
2172             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetExited ();
2173         else
2174         {
2175             if (log)
2176                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " failed to retrieve thread for tid %" PRIu64", cannot set thread state", __FUNCTION__, GetID (), pid);
2177         }
2178 
2179         if (is_main_thread)
2180         {
2181             SetExitStatus (convert_pid_status_to_exit_type (data), convert_pid_status_to_return_code (data), nullptr, true);
2182             // Resume the thread so it completely exits.
2183             Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
2184         }
2185         else
2186         {
2187             // FIXME figure out the path where we plan to reap the metadata for the thread.
2188         }
2189 
2190         break;
2191     }
2192 
2193     case 0:
2194     case TRAP_TRACE:
2195         // We receive this on single stepping.
2196         if (log)
2197             log->Printf ("NativeProcessLinux::%s() received trace event, pid = %" PRIu64 " (single stepping)", __FUNCTION__, pid);
2198 
2199         if (thread_sp)
2200         {
2201             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2202             SetCurrentThreadID (thread_sp->GetID ());
2203         }
2204         else
2205         {
2206             if (log)
2207                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 " single stepping received trace but thread not found", __FUNCTION__, GetID (), pid);
2208         }
2209 
2210         // Tell the process we have a stop (from single stepping).
2211         SetState (StateType::eStateStopped, true);
2212         break;
2213 
2214     case SI_KERNEL:
2215     case TRAP_BRKPT:
2216         if (log)
2217             log->Printf ("NativeProcessLinux::%s() received breakpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2218 
2219         // Mark the thread as stopped at breakpoint.
2220         if (thread_sp)
2221         {
2222             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2223             Error error = FixupBreakpointPCAsNeeded (thread_sp);
2224             if (error.Fail ())
2225             {
2226                 if (log)
2227                     log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " fixup: %s", __FUNCTION__, pid, error.AsCString ());
2228             }
2229         }
2230         else
2231         {
2232             if (log)
2233                 log->Printf ("NativeProcessLinux::%s()  pid = %" PRIu64 ": warning, cannot process software breakpoint since no thread metadata", __FUNCTION__, pid);
2234         }
2235 
2236 
2237         // Tell the process we have a stop from this thread.
2238         SetCurrentThreadID (pid);
2239         SetState (StateType::eStateStopped, true);
2240         break;
2241 
2242     case TRAP_HWBKPT:
2243         if (log)
2244             log->Printf ("NativeProcessLinux::%s() received watchpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2245 
2246         // Mark the thread as stopped at watchpoint.
2247         // The address is at (lldb::addr_t)info->si_addr if we need it.
2248         if (thread_sp)
2249             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2250         else
2251         {
2252             if (log)
2253                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ": warning, cannot process hardware breakpoint since no thread metadata", __FUNCTION__, GetID (), pid);
2254         }
2255 
2256         // Tell the process we have a stop from this thread.
2257         SetCurrentThreadID (pid);
2258         SetState (StateType::eStateStopped, true);
2259         break;
2260 
2261     case SIGTRAP:
2262     case (SIGTRAP | 0x80):
2263         if (log)
2264             log->Printf ("NativeProcessLinux::%s() received system call stop event, pid %" PRIu64 "tid %" PRIu64, __FUNCTION__, GetID (), pid);
2265         // Ignore these signals until we know more about them.
2266         Resume(pid, 0);
2267         break;
2268 
2269     default:
2270         assert(false && "Unexpected SIGTRAP code!");
2271         if (log)
2272             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)));
2273         break;
2274 
2275     }
2276 }
2277 
2278 void
2279 NativeProcessLinux::MonitorSignal(const siginfo_t *info, lldb::pid_t pid, bool exited)
2280 {
2281     int signo = info->si_signo;
2282 
2283     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2284 
2285     // POSIX says that process behaviour is undefined after it ignores a SIGFPE,
2286     // SIGILL, SIGSEGV, or SIGBUS *unless* that signal was generated by a
2287     // kill(2) or raise(3).  Similarly for tgkill(2) on Linux.
2288     //
2289     // IOW, user generated signals never generate what we consider to be a
2290     // "crash".
2291     //
2292     // Similarly, ACK signals generated by this monitor.
2293 
2294     // See if we can find a thread for this signal.
2295     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2296     if (!thread_sp)
2297     {
2298         if (log)
2299             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2300     }
2301 
2302     // Handle the signal.
2303     if (info->si_code == SI_TKILL || info->si_code == SI_USER)
2304     {
2305         if (log)
2306             log->Printf ("NativeProcessLinux::%s() received signal %s (%d) with code %s, (siginfo pid = %d (%s), waitpid pid = %" PRIu64 ")",
2307                             __FUNCTION__,
2308                             GetUnixSignals ().GetSignalAsCString (signo),
2309                             signo,
2310                             (info->si_code == SI_TKILL ? "SI_TKILL" : "SI_USER"),
2311                             info->si_pid,
2312                             (info->si_pid == getpid ()) ? "is monitor" : "is not monitor",
2313                             pid);
2314     }
2315 
2316     // Check for new thread notification.
2317     if ((info->si_pid == 0) && (info->si_code == SI_USER))
2318     {
2319         // A new thread creation is being signaled.  This is one of two parts that come in
2320         // a non-deterministic order.  pid is the thread id.
2321         if (log)
2322             log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": new thread notification",
2323                      __FUNCTION__, GetID (), pid);
2324 
2325         // Did we already create the thread?
2326         bool already_tracked = false;
2327         thread_sp = GetOrCreateThread (pid, already_tracked);
2328         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2329 
2330         // If the thread was already tracked, it means the main thread already received its SIGTRAP for the create.
2331         if (already_tracked)
2332         {
2333             // We can now resume this thread up since it is fully created.
2334             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2335             Resume (thread_sp->GetID (), LLDB_INVALID_SIGNAL_NUMBER);
2336         }
2337         else
2338         {
2339             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2340             // this thread is ready to go.
2341             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2342         }
2343 
2344         // Done handling.
2345         return;
2346     }
2347 
2348     // Check for thread stop notification.
2349     if ((info->si_pid == getpid ()) && (info->si_code == SI_TKILL) && (signo == SIGSTOP))
2350     {
2351         // This is a tgkill()-based stop.
2352         if (thread_sp)
2353         {
2354             // An inferior thread just stopped.  Mark it as such.
2355             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2356             SetCurrentThreadID (thread_sp->GetID ());
2357 
2358             // Remove this tid from the wait-for-stop set.
2359             Mutex::Locker locker (m_wait_for_stop_tids_mutex);
2360 
2361             auto removed_count = m_wait_for_stop_tids.erase (thread_sp->GetID ());
2362             if (removed_count < 1)
2363             {
2364                 log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": tgkill()-stopped thread not in m_wait_for_stop_tids",
2365                              __FUNCTION__, GetID (), thread_sp->GetID ());
2366 
2367             }
2368 
2369             // If this is the last thread in the m_wait_for_stop_tids, we need to notify
2370             // the delegate that a stop has occurred now that every thread that was supposed
2371             // to stop has stopped.
2372             if (m_wait_for_stop_tids.empty ())
2373             {
2374                 if (log)
2375                 {
2376                     log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ", setting process state to stopped now that all tids marked for stop have completed",
2377                                  __FUNCTION__,
2378                                  GetID (),
2379                                  pid);
2380                 }
2381                 SetState (StateType::eStateStopped, true);
2382             }
2383         }
2384 
2385         // Done handling.
2386         return;
2387     }
2388 
2389     if (log)
2390         log->Printf ("NativeProcessLinux::%s() received signal %s", __FUNCTION__, GetUnixSignals ().GetSignalAsCString (signo));
2391 
2392     switch (signo)
2393     {
2394     case SIGSEGV:
2395         {
2396             lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2397 
2398             // FIXME figure out how to propagate this properly.  Seems like it
2399             // should go in ThreadStopInfo.
2400             // We can get more details on the exact nature of the crash here.
2401             // ProcessMessage::CrashReason reason = GetCrashReasonForSIGSEGV(info);
2402             if (!exited)
2403             {
2404                 // This is just a pre-signal-delivery notification of the incoming signal.
2405                 // Send a stop to the debugger.
2406                 if (thread_sp)
2407                 {
2408                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2409                     SetCurrentThreadID (thread_sp->GetID ());
2410                 }
2411                 SetState (StateType::eStateStopped, true);
2412             }
2413             else
2414             {
2415                 if (thread_sp)
2416                 {
2417                     // FIXME figure out what type this is.
2418                     const uint64_t exception_type = static_cast<uint64_t> (SIGSEGV);
2419                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetCrashedWithException (exception_type, fault_addr);
2420                 }
2421                 SetState (StateType::eStateCrashed, true);
2422             }
2423         }
2424         break;
2425 
2426     case SIGABRT:
2427     case SIGILL:
2428     case SIGFPE:
2429     case SIGBUS:
2430         {
2431             // Break these out into separate cases once I have more data for each type of signal.
2432             lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2433             if (!exited)
2434             {
2435                 // This is just a pre-signal-delivery notification of the incoming signal.
2436                 // Send a stop to the debugger.
2437                 if (thread_sp)
2438                 {
2439                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2440                     SetCurrentThreadID (thread_sp->GetID ());
2441                 }
2442                 SetState (StateType::eStateStopped, true);
2443             }
2444             else
2445             {
2446                 if (thread_sp)
2447                 {
2448                     // FIXME figure out how to report exit by signal correctly.
2449                     const uint64_t exception_type = static_cast<uint64_t> (SIGABRT);
2450                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetCrashedWithException (exception_type, fault_addr);
2451                 }
2452                 SetState (StateType::eStateCrashed, true);
2453             }
2454         }
2455         break;
2456 
2457     default:
2458         if (log)
2459             log->Printf ("NativeProcessLinux::%s unhandled signal %s (%d)", __FUNCTION__, GetUnixSignals ().GetSignalAsCString (signo), signo);
2460         break;
2461     }
2462 }
2463 
2464 Error
2465 NativeProcessLinux::Resume (const ResumeActionList &resume_actions)
2466 {
2467     Error error;
2468 
2469     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_THREAD));
2470     if (log)
2471         log->Printf ("NativeProcessLinux::%s called: pid %" PRIu64, __FUNCTION__, GetID ());
2472 
2473     int run_thread_count = 0;
2474     int stop_thread_count = 0;
2475     int step_thread_count = 0;
2476 
2477     std::vector<NativeThreadProtocolSP> new_stop_threads;
2478 
2479     Mutex::Locker locker (m_threads_mutex);
2480     for (auto thread_sp : m_threads)
2481     {
2482         assert (thread_sp && "thread list should not contain NULL threads");
2483         NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get ());
2484 
2485         const ResumeAction *const action = resume_actions.GetActionForThread (thread_sp->GetID (), true);
2486         assert (action && "NULL ResumeAction returned for thread during Resume ()");
2487 
2488         if (log)
2489         {
2490             log->Printf ("NativeProcessLinux::%s processing resume action state %s for pid %" PRIu64 " tid %" PRIu64,
2491                     __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2492         }
2493 
2494         switch (action->state)
2495         {
2496         case eStateRunning:
2497             // Run the thread, possibly feeding it the signal.
2498             linux_thread_p->SetRunning ();
2499             if (action->signal > 0)
2500             {
2501                 // Resume the thread and deliver the given signal,
2502                 // then mark as delivered.
2503                 Resume (thread_sp->GetID (), action->signal);
2504                 resume_actions.SetSignalHandledForThread (thread_sp->GetID ());
2505             }
2506             else
2507             {
2508                 // Just resume the thread with no signal.
2509                 Resume (thread_sp->GetID (), LLDB_INVALID_SIGNAL_NUMBER);
2510             }
2511             ++run_thread_count;
2512             break;
2513 
2514         case eStateStepping:
2515             // Note: if we have multiple threads, we may need to stop
2516             // the other threads first, then step this one.
2517             linux_thread_p->SetStepping ();
2518             if (SingleStep (thread_sp->GetID (), 0))
2519             {
2520                 if (log)
2521                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " single step succeeded",
2522                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2523             }
2524             else
2525             {
2526                 if (log)
2527                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " single step failed",
2528                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2529             }
2530             ++step_thread_count;
2531             break;
2532 
2533         case eStateSuspended:
2534         case eStateStopped:
2535             if (!StateIsStoppedState (linux_thread_p->GetState (), false))
2536                 new_stop_threads.push_back (thread_sp);
2537             else
2538             {
2539                 if (log)
2540                     log->Printf ("NativeProcessLinux::%s no need to stop pid %" PRIu64 " tid %" PRIu64 ", thread state already %s",
2541                                  __FUNCTION__, GetID (), thread_sp->GetID (), StateAsCString (linux_thread_p->GetState ()));
2542             }
2543 
2544             ++stop_thread_count;
2545             break;
2546 
2547         default:
2548             return Error ("NativeProcessLinux::%s (): unexpected state %s specified for pid %" PRIu64 ", tid %" PRIu64,
2549                     __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2550         }
2551     }
2552 
2553     // If any thread was set to run, notify the process state as running.
2554     if (run_thread_count > 0)
2555         SetState (StateType::eStateRunning, true);
2556 
2557     // Now do a tgkill SIGSTOP on each thread we want to stop.
2558     if (!new_stop_threads.empty ())
2559     {
2560         // Lock the m_wait_for_stop_tids set so we can fill it with every thread we expect to have stopped.
2561         Mutex::Locker stop_thread_id_locker (m_wait_for_stop_tids_mutex);
2562         for (auto thread_sp : new_stop_threads)
2563         {
2564             // Send a stop signal to the thread.
2565             const int result = tgkill (GetID (), thread_sp->GetID (), SIGSTOP);
2566             if (result != 0)
2567             {
2568                 // tgkill failed.
2569                 if (log)
2570                     log->Printf ("NativeProcessLinux::%s error: tgkill SIGSTOP for pid %" PRIu64 " tid %" PRIu64 "failed, retval %d",
2571                                  __FUNCTION__, GetID (), thread_sp->GetID (), result);
2572             }
2573             else
2574             {
2575                 // tgkill succeeded.  Don't mark the thread state, though.  Let the signal
2576                 // handling mark it.
2577                 if (log)
2578                     log->Printf ("NativeProcessLinux::%s tgkill SIGSTOP for pid %" PRIu64 " tid %" PRIu64 " succeeded",
2579                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2580 
2581                 // Add it to the set of threads we expect to signal a stop.
2582                 // We won't tell the delegate about it until this list drains to empty.
2583                 m_wait_for_stop_tids.insert (thread_sp->GetID ());
2584             }
2585         }
2586     }
2587 
2588     return error;
2589 }
2590 
2591 Error
2592 NativeProcessLinux::Halt ()
2593 {
2594     Error error;
2595 
2596     // FIXME check if we're already stopped
2597     const bool is_stopped = false;
2598     if (is_stopped)
2599         return error;
2600 
2601     if (kill (GetID (), SIGSTOP) != 0)
2602         error.SetErrorToErrno ();
2603 
2604     return error;
2605 }
2606 
2607 Error
2608 NativeProcessLinux::Detach ()
2609 {
2610     Error error;
2611 
2612     // Tell ptrace to detach from the process.
2613     if (GetID () != LLDB_INVALID_PROCESS_ID)
2614         error = Detach (GetID ());
2615 
2616     // Stop monitoring the inferior.
2617     StopMonitor ();
2618 
2619     // No error.
2620     return error;
2621 }
2622 
2623 Error
2624 NativeProcessLinux::Signal (int signo)
2625 {
2626     Error error;
2627 
2628     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2629     if (log)
2630         log->Printf ("NativeProcessLinux::%s: sending signal %d (%s) to pid %" PRIu64,
2631                 __FUNCTION__, signo,  GetUnixSignals ().GetSignalAsCString (signo), GetID ());
2632 
2633     if (kill(GetID(), signo))
2634         error.SetErrorToErrno();
2635 
2636     return error;
2637 }
2638 
2639 Error
2640 NativeProcessLinux::Kill ()
2641 {
2642     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2643     if (log)
2644         log->Printf ("NativeProcessLinux::%s called for PID %" PRIu64, __FUNCTION__, GetID ());
2645 
2646     Error error;
2647 
2648     switch (m_state)
2649     {
2650         case StateType::eStateInvalid:
2651         case StateType::eStateExited:
2652         case StateType::eStateCrashed:
2653         case StateType::eStateDetached:
2654         case StateType::eStateUnloaded:
2655             // Nothing to do - the process is already dead.
2656             if (log)
2657                 log->Printf ("NativeProcessLinux::%s ignored for PID %" PRIu64 " due to current state: %s", __FUNCTION__, GetID (), StateAsCString (m_state));
2658             return error;
2659 
2660         case StateType::eStateConnected:
2661         case StateType::eStateAttaching:
2662         case StateType::eStateLaunching:
2663         case StateType::eStateStopped:
2664         case StateType::eStateRunning:
2665         case StateType::eStateStepping:
2666         case StateType::eStateSuspended:
2667             // We can try to kill a process in these states.
2668             break;
2669     }
2670 
2671     if (kill (GetID (), SIGKILL) != 0)
2672     {
2673         error.SetErrorToErrno ();
2674         return error;
2675     }
2676 
2677     return error;
2678 }
2679 
2680 static Error
2681 ParseMemoryRegionInfoFromProcMapsLine (const std::string &maps_line, MemoryRegionInfo &memory_region_info)
2682 {
2683     memory_region_info.Clear();
2684 
2685     StringExtractor line_extractor (maps_line.c_str ());
2686 
2687     // Format: {address_start_hex}-{address_end_hex} perms offset  dev   inode   pathname
2688     // perms: rwxp   (letter is present if set, '-' if not, final character is p=private, s=shared).
2689 
2690     // Parse out the starting address
2691     lldb::addr_t start_address = line_extractor.GetHexMaxU64 (false, 0);
2692 
2693     // Parse out hyphen separating start and end address from range.
2694     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != '-'))
2695         return Error ("malformed /proc/{pid}/maps entry, missing dash between address range");
2696 
2697     // Parse out the ending address
2698     lldb::addr_t end_address = line_extractor.GetHexMaxU64 (false, start_address);
2699 
2700     // Parse out the space after the address.
2701     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != ' '))
2702         return Error ("malformed /proc/{pid}/maps entry, missing space after range");
2703 
2704     // Save the range.
2705     memory_region_info.GetRange ().SetRangeBase (start_address);
2706     memory_region_info.GetRange ().SetRangeEnd (end_address);
2707 
2708     // Parse out each permission entry.
2709     if (line_extractor.GetBytesLeft () < 4)
2710         return Error ("malformed /proc/{pid}/maps entry, missing some portion of permissions");
2711 
2712     // Handle read permission.
2713     const char read_perm_char = line_extractor.GetChar ();
2714     if (read_perm_char == 'r')
2715         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eYes);
2716     else
2717     {
2718         assert ( (read_perm_char == '-') && "unexpected /proc/{pid}/maps read permission char" );
2719         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
2720     }
2721 
2722     // Handle write permission.
2723     const char write_perm_char = line_extractor.GetChar ();
2724     if (write_perm_char == 'w')
2725         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eYes);
2726     else
2727     {
2728         assert ( (write_perm_char == '-') && "unexpected /proc/{pid}/maps write permission char" );
2729         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
2730     }
2731 
2732     // Handle execute permission.
2733     const char exec_perm_char = line_extractor.GetChar ();
2734     if (exec_perm_char == 'x')
2735         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eYes);
2736     else
2737     {
2738         assert ( (exec_perm_char == '-') && "unexpected /proc/{pid}/maps exec permission char" );
2739         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
2740     }
2741 
2742     return Error ();
2743 }
2744 
2745 Error
2746 NativeProcessLinux::GetMemoryRegionInfo (lldb::addr_t load_addr, MemoryRegionInfo &range_info)
2747 {
2748     // FIXME review that the final memory region returned extends to the end of the virtual address space,
2749     // with no perms if it is not mapped.
2750 
2751     // Use an approach that reads memory regions from /proc/{pid}/maps.
2752     // Assume proc maps entries are in ascending order.
2753     // FIXME assert if we find differently.
2754     Mutex::Locker locker (m_mem_region_cache_mutex);
2755 
2756     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2757     Error error;
2758 
2759     if (m_supports_mem_region == LazyBool::eLazyBoolNo)
2760     {
2761         // We're done.
2762         error.SetErrorString ("unsupported");
2763         return error;
2764     }
2765 
2766     // If our cache is empty, pull the latest.  There should always be at least one memory region
2767     // if memory region handling is supported.
2768     if (m_mem_region_cache.empty ())
2769     {
2770         error = ProcFileReader::ProcessLineByLine (GetID (), "maps",
2771              [&] (const std::string &line) -> bool
2772              {
2773                  MemoryRegionInfo info;
2774                  const Error parse_error = ParseMemoryRegionInfoFromProcMapsLine (line, info);
2775                  if (parse_error.Success ())
2776                  {
2777                      m_mem_region_cache.push_back (info);
2778                      return true;
2779                  }
2780                  else
2781                  {
2782                      if (log)
2783                          log->Printf ("NativeProcessLinux::%s failed to parse proc maps line '%s': %s", __FUNCTION__, line.c_str (), error.AsCString ());
2784                      return false;
2785                  }
2786              });
2787 
2788         // If we had an error, we'll mark unsupported.
2789         if (error.Fail ())
2790         {
2791             m_supports_mem_region = LazyBool::eLazyBoolNo;
2792             return error;
2793         }
2794         else if (m_mem_region_cache.empty ())
2795         {
2796             // No entries after attempting to read them.  This shouldn't happen if /proc/{pid}/maps
2797             // is supported.  Assume we don't support map entries via procfs.
2798             if (log)
2799                 log->Printf ("NativeProcessLinux::%s failed to find any procfs maps entries, assuming no support for memory region metadata retrieval", __FUNCTION__);
2800             m_supports_mem_region = LazyBool::eLazyBoolNo;
2801             error.SetErrorString ("not supported");
2802             return error;
2803         }
2804 
2805         if (log)
2806             log->Printf ("NativeProcessLinux::%s read %" PRIu64 " memory region entries from /proc/%" PRIu64 "/maps", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()), GetID ());
2807 
2808         // We support memory retrieval, remember that.
2809         m_supports_mem_region = LazyBool::eLazyBoolYes;
2810     }
2811     else
2812     {
2813         if (log)
2814             log->Printf ("NativeProcessLinux::%s reusing %" PRIu64 " cached memory region entries", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
2815     }
2816 
2817     lldb::addr_t prev_base_address = 0;
2818 
2819     // FIXME start by finding the last region that is <= target address using binary search.  Data is sorted.
2820     // There can be a ton of regions on pthreads apps with lots of threads.
2821     for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end (); ++it)
2822     {
2823         MemoryRegionInfo &proc_entry_info = *it;
2824 
2825         // Sanity check assumption that /proc/{pid}/maps entries are ascending.
2826         assert ((proc_entry_info.GetRange ().GetRangeBase () >= prev_base_address) && "descending /proc/pid/maps entries detected, unexpected");
2827         prev_base_address = proc_entry_info.GetRange ().GetRangeBase ();
2828 
2829         // If the target address comes before this entry, indicate distance to next region.
2830         if (load_addr < proc_entry_info.GetRange ().GetRangeBase ())
2831         {
2832             range_info.GetRange ().SetRangeBase (load_addr);
2833             range_info.GetRange ().SetByteSize (proc_entry_info.GetRange ().GetRangeBase () - load_addr);
2834             range_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
2835             range_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
2836             range_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
2837 
2838             return error;
2839         }
2840         else if (proc_entry_info.GetRange ().Contains (load_addr))
2841         {
2842             // The target address is within the memory region we're processing here.
2843             range_info = proc_entry_info;
2844             return error;
2845         }
2846 
2847         // The target memory address comes somewhere after the region we just parsed.
2848     }
2849 
2850     // If we made it here, we didn't find an entry that contained the given address.
2851     error.SetErrorString ("address comes after final region");
2852 
2853     if (log)
2854         log->Printf ("NativeProcessLinux::%s failed to find map entry for address 0x%" PRIx64 ": %s", __FUNCTION__, load_addr, error.AsCString ());
2855 
2856     return error;
2857 }
2858 
2859 void
2860 NativeProcessLinux::DoStopIDBumped (uint32_t newBumpId)
2861 {
2862     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2863     if (log)
2864         log->Printf ("NativeProcessLinux::%s(newBumpId=%" PRIu32 ") called", __FUNCTION__, newBumpId);
2865 
2866     {
2867         Mutex::Locker locker (m_mem_region_cache_mutex);
2868         if (log)
2869             log->Printf ("NativeProcessLinux::%s clearing %" PRIu64 " entries from the cache", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
2870         m_mem_region_cache.clear ();
2871     }
2872 }
2873 
2874 Error
2875 NativeProcessLinux::AllocateMemory (
2876     lldb::addr_t size,
2877     uint32_t permissions,
2878     lldb::addr_t &addr)
2879 {
2880     // FIXME implementing this requires the equivalent of
2881     // InferiorCallPOSIX::InferiorCallMmap, which depends on
2882     // functional ThreadPlans working with Native*Protocol.
2883 #if 1
2884     return Error ("not implemented yet");
2885 #else
2886     addr = LLDB_INVALID_ADDRESS;
2887 
2888     unsigned prot = 0;
2889     if (permissions & lldb::ePermissionsReadable)
2890         prot |= eMmapProtRead;
2891     if (permissions & lldb::ePermissionsWritable)
2892         prot |= eMmapProtWrite;
2893     if (permissions & lldb::ePermissionsExecutable)
2894         prot |= eMmapProtExec;
2895 
2896     // TODO implement this directly in NativeProcessLinux
2897     // (and lift to NativeProcessPOSIX if/when that class is
2898     // refactored out).
2899     if (InferiorCallMmap(this, addr, 0, size, prot,
2900                          eMmapFlagsAnon | eMmapFlagsPrivate, -1, 0)) {
2901         m_addr_to_mmap_size[addr] = size;
2902         return Error ();
2903     } else {
2904         addr = LLDB_INVALID_ADDRESS;
2905         return Error("unable to allocate %" PRIu64 " bytes of memory with permissions %s", size, GetPermissionsAsCString (permissions));
2906     }
2907 #endif
2908 }
2909 
2910 Error
2911 NativeProcessLinux::DeallocateMemory (lldb::addr_t addr)
2912 {
2913     // FIXME see comments in AllocateMemory - required lower-level
2914     // bits not in place yet (ThreadPlans)
2915     return Error ("not implemented");
2916 }
2917 
2918 lldb::addr_t
2919 NativeProcessLinux::GetSharedLibraryInfoAddress ()
2920 {
2921 #if 1
2922     // punt on this for now
2923     return LLDB_INVALID_ADDRESS;
2924 #else
2925     // Return the image info address for the exe module
2926 #if 1
2927     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2928 
2929     ModuleSP module_sp;
2930     Error error = GetExeModuleSP (module_sp);
2931     if (error.Fail ())
2932     {
2933          if (log)
2934             log->Warning ("NativeProcessLinux::%s failed to retrieve exe module: %s", __FUNCTION__, error.AsCString ());
2935         return LLDB_INVALID_ADDRESS;
2936     }
2937 
2938     if (module_sp == nullptr)
2939     {
2940          if (log)
2941             log->Warning ("NativeProcessLinux::%s exe module returned was NULL", __FUNCTION__);
2942          return LLDB_INVALID_ADDRESS;
2943     }
2944 
2945     ObjectFileSP object_file_sp = module_sp->GetObjectFile ();
2946     if (object_file_sp == nullptr)
2947     {
2948          if (log)
2949             log->Warning ("NativeProcessLinux::%s exe module returned a NULL object file", __FUNCTION__);
2950          return LLDB_INVALID_ADDRESS;
2951     }
2952 
2953     return obj_file_sp->GetImageInfoAddress();
2954 #else
2955     Target *target = &GetTarget();
2956     ObjectFile *obj_file = target->GetExecutableModule()->GetObjectFile();
2957     Address addr = obj_file->GetImageInfoAddress(target);
2958 
2959     if (addr.IsValid())
2960         return addr.GetLoadAddress(target);
2961     return LLDB_INVALID_ADDRESS;
2962 #endif
2963 #endif // punt on this for now
2964 }
2965 
2966 size_t
2967 NativeProcessLinux::UpdateThreads ()
2968 {
2969     // The NativeProcessLinux monitoring threads are always up to date
2970     // with respect to thread state and they keep the thread list
2971     // populated properly. All this method needs to do is return the
2972     // thread count.
2973     Mutex::Locker locker (m_threads_mutex);
2974     return m_threads.size ();
2975 }
2976 
2977 bool
2978 NativeProcessLinux::GetArchitecture (ArchSpec &arch) const
2979 {
2980     arch = m_arch;
2981     return true;
2982 }
2983 
2984 Error
2985 NativeProcessLinux::GetSoftwareBreakpointSize (NativeRegisterContextSP context_sp, uint32_t &actual_opcode_size)
2986 {
2987     // FIXME put this behind a breakpoint protocol class that can be
2988     // set per architecture.  Need ARM, MIPS support here.
2989     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
2990     static const uint8_t g_i386_opcode [] = { 0xCC };
2991 
2992     switch (m_arch.GetMachine ())
2993     {
2994         case llvm::Triple::aarch64:
2995             actual_opcode_size = static_cast<uint32_t> (sizeof(g_aarch64_opcode));
2996             return Error ();
2997 
2998         case llvm::Triple::x86:
2999         case llvm::Triple::x86_64:
3000             actual_opcode_size = static_cast<uint32_t> (sizeof(g_i386_opcode));
3001             return Error ();
3002 
3003         default:
3004             assert(false && "CPU type not supported!");
3005             return Error ("CPU type not supported");
3006     }
3007 }
3008 
3009 Error
3010 NativeProcessLinux::SetBreakpoint (lldb::addr_t addr, uint32_t size, bool hardware)
3011 {
3012     if (hardware)
3013         return Error ("NativeProcessLinux does not support hardware breakpoints");
3014     else
3015         return SetSoftwareBreakpoint (addr, size);
3016 }
3017 
3018 Error
3019 NativeProcessLinux::GetSoftwareBreakpointTrapOpcode (size_t trap_opcode_size_hint, size_t &actual_opcode_size, const uint8_t *&trap_opcode_bytes)
3020 {
3021     // FIXME put this behind a breakpoint protocol class that can be
3022     // set per architecture.  Need ARM, MIPS support here.
3023     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
3024     static const uint8_t g_i386_opcode [] = { 0xCC };
3025 
3026     switch (m_arch.GetMachine ())
3027     {
3028     case llvm::Triple::aarch64:
3029         trap_opcode_bytes = g_aarch64_opcode;
3030         actual_opcode_size = sizeof(g_aarch64_opcode);
3031         return Error ();
3032 
3033     case llvm::Triple::x86:
3034     case llvm::Triple::x86_64:
3035         trap_opcode_bytes = g_i386_opcode;
3036         actual_opcode_size = sizeof(g_i386_opcode);
3037         return Error ();
3038 
3039     default:
3040         assert(false && "CPU type not supported!");
3041         return Error ("CPU type not supported");
3042     }
3043 }
3044 
3045 #if 0
3046 ProcessMessage::CrashReason
3047 NativeProcessLinux::GetCrashReasonForSIGSEGV(const siginfo_t *info)
3048 {
3049     ProcessMessage::CrashReason reason;
3050     assert(info->si_signo == SIGSEGV);
3051 
3052     reason = ProcessMessage::eInvalidCrashReason;
3053 
3054     switch (info->si_code)
3055     {
3056     default:
3057         assert(false && "unexpected si_code for SIGSEGV");
3058         break;
3059     case SI_KERNEL:
3060         // Linux will occasionally send spurious SI_KERNEL codes.
3061         // (this is poorly documented in sigaction)
3062         // One way to get this is via unaligned SIMD loads.
3063         reason = ProcessMessage::eInvalidAddress; // for lack of anything better
3064         break;
3065     case SEGV_MAPERR:
3066         reason = ProcessMessage::eInvalidAddress;
3067         break;
3068     case SEGV_ACCERR:
3069         reason = ProcessMessage::ePrivilegedAddress;
3070         break;
3071     }
3072 
3073     return reason;
3074 }
3075 #endif
3076 
3077 
3078 #if 0
3079 ProcessMessage::CrashReason
3080 NativeProcessLinux::GetCrashReasonForSIGILL(const siginfo_t *info)
3081 {
3082     ProcessMessage::CrashReason reason;
3083     assert(info->si_signo == SIGILL);
3084 
3085     reason = ProcessMessage::eInvalidCrashReason;
3086 
3087     switch (info->si_code)
3088     {
3089     default:
3090         assert(false && "unexpected si_code for SIGILL");
3091         break;
3092     case ILL_ILLOPC:
3093         reason = ProcessMessage::eIllegalOpcode;
3094         break;
3095     case ILL_ILLOPN:
3096         reason = ProcessMessage::eIllegalOperand;
3097         break;
3098     case ILL_ILLADR:
3099         reason = ProcessMessage::eIllegalAddressingMode;
3100         break;
3101     case ILL_ILLTRP:
3102         reason = ProcessMessage::eIllegalTrap;
3103         break;
3104     case ILL_PRVOPC:
3105         reason = ProcessMessage::ePrivilegedOpcode;
3106         break;
3107     case ILL_PRVREG:
3108         reason = ProcessMessage::ePrivilegedRegister;
3109         break;
3110     case ILL_COPROC:
3111         reason = ProcessMessage::eCoprocessorError;
3112         break;
3113     case ILL_BADSTK:
3114         reason = ProcessMessage::eInternalStackError;
3115         break;
3116     }
3117 
3118     return reason;
3119 }
3120 #endif
3121 
3122 #if 0
3123 ProcessMessage::CrashReason
3124 NativeProcessLinux::GetCrashReasonForSIGFPE(const siginfo_t *info)
3125 {
3126     ProcessMessage::CrashReason reason;
3127     assert(info->si_signo == SIGFPE);
3128 
3129     reason = ProcessMessage::eInvalidCrashReason;
3130 
3131     switch (info->si_code)
3132     {
3133     default:
3134         assert(false && "unexpected si_code for SIGFPE");
3135         break;
3136     case FPE_INTDIV:
3137         reason = ProcessMessage::eIntegerDivideByZero;
3138         break;
3139     case FPE_INTOVF:
3140         reason = ProcessMessage::eIntegerOverflow;
3141         break;
3142     case FPE_FLTDIV:
3143         reason = ProcessMessage::eFloatDivideByZero;
3144         break;
3145     case FPE_FLTOVF:
3146         reason = ProcessMessage::eFloatOverflow;
3147         break;
3148     case FPE_FLTUND:
3149         reason = ProcessMessage::eFloatUnderflow;
3150         break;
3151     case FPE_FLTRES:
3152         reason = ProcessMessage::eFloatInexactResult;
3153         break;
3154     case FPE_FLTINV:
3155         reason = ProcessMessage::eFloatInvalidOperation;
3156         break;
3157     case FPE_FLTSUB:
3158         reason = ProcessMessage::eFloatSubscriptRange;
3159         break;
3160     }
3161 
3162     return reason;
3163 }
3164 #endif
3165 
3166 #if 0
3167 ProcessMessage::CrashReason
3168 NativeProcessLinux::GetCrashReasonForSIGBUS(const siginfo_t *info)
3169 {
3170     ProcessMessage::CrashReason reason;
3171     assert(info->si_signo == SIGBUS);
3172 
3173     reason = ProcessMessage::eInvalidCrashReason;
3174 
3175     switch (info->si_code)
3176     {
3177     default:
3178         assert(false && "unexpected si_code for SIGBUS");
3179         break;
3180     case BUS_ADRALN:
3181         reason = ProcessMessage::eIllegalAlignment;
3182         break;
3183     case BUS_ADRERR:
3184         reason = ProcessMessage::eIllegalAddress;
3185         break;
3186     case BUS_OBJERR:
3187         reason = ProcessMessage::eHardwareError;
3188         break;
3189     }
3190 
3191     return reason;
3192 }
3193 #endif
3194 
3195 void
3196 NativeProcessLinux::ServeOperation(OperationArgs *args)
3197 {
3198     NativeProcessLinux *monitor = args->m_monitor;
3199 
3200     // We are finised with the arguments and are ready to go.  Sync with the
3201     // parent thread and start serving operations on the inferior.
3202     sem_post(&args->m_semaphore);
3203 
3204     for(;;)
3205     {
3206         // wait for next pending operation
3207         if (sem_wait(&monitor->m_operation_pending))
3208         {
3209             if (errno == EINTR)
3210                 continue;
3211             assert(false && "Unexpected errno from sem_wait");
3212         }
3213 
3214         reinterpret_cast<Operation*>(monitor->m_operation)->Execute(monitor);
3215 
3216         // notify calling thread that operation is complete
3217         sem_post(&monitor->m_operation_done);
3218     }
3219 }
3220 
3221 void
3222 NativeProcessLinux::DoOperation(void *op)
3223 {
3224     Mutex::Locker lock(m_operation_mutex);
3225 
3226     m_operation = op;
3227 
3228     // notify operation thread that an operation is ready to be processed
3229     sem_post(&m_operation_pending);
3230 
3231     // wait for operation to complete
3232     while (sem_wait(&m_operation_done))
3233     {
3234         if (errno == EINTR)
3235             continue;
3236         assert(false && "Unexpected errno from sem_wait");
3237     }
3238 }
3239 
3240 Error
3241 NativeProcessLinux::ReadMemory (lldb::addr_t addr, void *buf, lldb::addr_t size, lldb::addr_t &bytes_read)
3242 {
3243     ReadOperation op(addr, buf, size, bytes_read);
3244     DoOperation(&op);
3245     return op.GetError ();
3246 }
3247 
3248 Error
3249 NativeProcessLinux::WriteMemory (lldb::addr_t addr, const void *buf, lldb::addr_t size, lldb::addr_t &bytes_written)
3250 {
3251     WriteOperation op(addr, buf, size, bytes_written);
3252     DoOperation(&op);
3253     return op.GetError ();
3254 }
3255 
3256 bool
3257 NativeProcessLinux::ReadRegisterValue(lldb::tid_t tid, uint32_t offset, const char* reg_name,
3258                                   uint32_t size, RegisterValue &value)
3259 {
3260     bool result;
3261     ReadRegOperation op(tid, offset, reg_name, value, result);
3262     DoOperation(&op);
3263     return result;
3264 }
3265 
3266 bool
3267 NativeProcessLinux::WriteRegisterValue(lldb::tid_t tid, unsigned offset,
3268                                    const char* reg_name, const RegisterValue &value)
3269 {
3270     bool result;
3271     WriteRegOperation op(tid, offset, reg_name, value, result);
3272     DoOperation(&op);
3273     return result;
3274 }
3275 
3276 bool
3277 NativeProcessLinux::ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3278 {
3279     bool result;
3280     ReadGPROperation op(tid, buf, buf_size, result);
3281     DoOperation(&op);
3282     return result;
3283 }
3284 
3285 bool
3286 NativeProcessLinux::ReadFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3287 {
3288     bool result;
3289     ReadFPROperation op(tid, buf, buf_size, result);
3290     DoOperation(&op);
3291     return result;
3292 }
3293 
3294 bool
3295 NativeProcessLinux::ReadRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3296 {
3297     bool result;
3298     ReadRegisterSetOperation op(tid, buf, buf_size, regset, result);
3299     DoOperation(&op);
3300     return result;
3301 }
3302 
3303 bool
3304 NativeProcessLinux::WriteGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3305 {
3306     bool result;
3307     WriteGPROperation op(tid, buf, buf_size, result);
3308     DoOperation(&op);
3309     return result;
3310 }
3311 
3312 bool
3313 NativeProcessLinux::WriteFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3314 {
3315     bool result;
3316     WriteFPROperation op(tid, buf, buf_size, result);
3317     DoOperation(&op);
3318     return result;
3319 }
3320 
3321 bool
3322 NativeProcessLinux::WriteRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3323 {
3324     bool result;
3325     WriteRegisterSetOperation op(tid, buf, buf_size, regset, result);
3326     DoOperation(&op);
3327     return result;
3328 }
3329 
3330 bool
3331 NativeProcessLinux::Resume (lldb::tid_t tid, uint32_t signo)
3332 {
3333     bool result;
3334     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3335 
3336     if (log)
3337         log->Printf ("NativeProcessLinux::%s() resuming thread = %"  PRIu64 " with signal %s", __FUNCTION__, tid,
3338                                  GetUnixSignals().GetSignalAsCString (signo));
3339     ResumeOperation op (tid, signo, result);
3340     DoOperation (&op);
3341     if (log)
3342         log->Printf ("NativeProcessLinux::%s() resuming result = %s", __FUNCTION__, result ? "true" : "false");
3343     return result;
3344 }
3345 
3346 bool
3347 NativeProcessLinux::SingleStep(lldb::tid_t tid, uint32_t signo)
3348 {
3349     bool result;
3350     SingleStepOperation op(tid, signo, result);
3351     DoOperation(&op);
3352     return result;
3353 }
3354 
3355 bool
3356 NativeProcessLinux::GetSignalInfo(lldb::tid_t tid, void *siginfo, int &ptrace_err)
3357 {
3358     bool result;
3359     SiginfoOperation op(tid, siginfo, result, ptrace_err);
3360     DoOperation(&op);
3361     return result;
3362 }
3363 
3364 bool
3365 NativeProcessLinux::GetEventMessage(lldb::tid_t tid, unsigned long *message)
3366 {
3367     bool result;
3368     EventMessageOperation op(tid, message, result);
3369     DoOperation(&op);
3370     return result;
3371 }
3372 
3373 lldb_private::Error
3374 NativeProcessLinux::Detach(lldb::tid_t tid)
3375 {
3376     lldb_private::Error error;
3377     if (tid != LLDB_INVALID_THREAD_ID)
3378     {
3379         DetachOperation op(tid, error);
3380         DoOperation(&op);
3381     }
3382     return error;
3383 }
3384 
3385 bool
3386 NativeProcessLinux::DupDescriptor(const char *path, int fd, int flags)
3387 {
3388     int target_fd = open(path, flags, 0666);
3389 
3390     if (target_fd == -1)
3391         return false;
3392 
3393     return (dup2(target_fd, fd) == -1) ? false : true;
3394 }
3395 
3396 void
3397 NativeProcessLinux::StopMonitoringChildProcess()
3398 {
3399     lldb::thread_result_t thread_result;
3400 
3401     if (IS_VALID_LLDB_HOST_THREAD(m_monitor_thread))
3402     {
3403         Host::ThreadCancel(m_monitor_thread, NULL);
3404         Host::ThreadJoin(m_monitor_thread, &thread_result, NULL);
3405         m_monitor_thread = LLDB_INVALID_HOST_THREAD;
3406     }
3407 }
3408 
3409 void
3410 NativeProcessLinux::StopMonitor()
3411 {
3412     StopMonitoringChildProcess();
3413     StopOpThread();
3414     sem_destroy(&m_operation_pending);
3415     sem_destroy(&m_operation_done);
3416 
3417     // TODO: validate whether this still holds, fix up comment.
3418     // Note: ProcessPOSIX passes the m_terminal_fd file descriptor to
3419     // Process::SetSTDIOFileDescriptor, which in turn transfers ownership of
3420     // the descriptor to a ConnectionFileDescriptor object.  Consequently
3421     // even though still has the file descriptor, we shouldn't close it here.
3422 }
3423 
3424 void
3425 NativeProcessLinux::StopOpThread()
3426 {
3427     lldb::thread_result_t result;
3428 
3429     if (!IS_VALID_LLDB_HOST_THREAD(m_operation_thread))
3430         return;
3431 
3432     Host::ThreadCancel(m_operation_thread, NULL);
3433     Host::ThreadJoin(m_operation_thread, &result, NULL);
3434     m_operation_thread = LLDB_INVALID_HOST_THREAD;
3435 }
3436 
3437 bool
3438 NativeProcessLinux::HasThreadNoLock (lldb::tid_t thread_id)
3439 {
3440     for (auto thread_sp : m_threads)
3441     {
3442         assert (thread_sp && "thread list should not contain NULL threads");
3443         if (thread_sp->GetID () == thread_id)
3444         {
3445             // We have this thread.
3446             return true;
3447         }
3448     }
3449 
3450     // We don't have this thread.
3451     return false;
3452 }
3453 
3454 NativeThreadProtocolSP
3455 NativeProcessLinux::MaybeGetThreadNoLock (lldb::tid_t thread_id)
3456 {
3457     // CONSIDER organize threads by map - we can do better than linear.
3458     for (auto thread_sp : m_threads)
3459     {
3460         if (thread_sp->GetID () == thread_id)
3461             return thread_sp;
3462     }
3463 
3464     // We don't have this thread.
3465     return NativeThreadProtocolSP ();
3466 }
3467 
3468 bool
3469 NativeProcessLinux::StopTrackingThread (lldb::tid_t thread_id)
3470 {
3471     Mutex::Locker locker (m_threads_mutex);
3472     for (auto it = m_threads.begin (); it != m_threads.end (); ++it)
3473     {
3474         if (*it && ((*it)->GetID () == thread_id))
3475         {
3476             m_threads.erase (it);
3477             return true;
3478         }
3479     }
3480 
3481     // Didn't find it.
3482     return false;
3483 }
3484 
3485 NativeThreadProtocolSP
3486 NativeProcessLinux::AddThread (lldb::tid_t thread_id)
3487 {
3488     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3489 
3490     Mutex::Locker locker (m_threads_mutex);
3491 
3492     if (log)
3493     {
3494         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " adding thread with tid %" PRIu64,
3495                 __FUNCTION__,
3496                 GetID (),
3497                 thread_id);
3498     }
3499 
3500     assert (!HasThreadNoLock (thread_id) && "attempted to add a thread by id that already exists");
3501 
3502     // If this is the first thread, save it as the current thread
3503     if (m_threads.empty ())
3504         SetCurrentThreadID (thread_id);
3505 
3506     NativeThreadProtocolSP thread_sp (new NativeThreadLinux (this, thread_id));
3507     m_threads.push_back (thread_sp);
3508 
3509     return thread_sp;
3510 }
3511 
3512 NativeThreadProtocolSP
3513 NativeProcessLinux::GetOrCreateThread (lldb::tid_t thread_id, bool &created)
3514 {
3515     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3516 
3517     Mutex::Locker locker (m_threads_mutex);
3518     if (log)
3519     {
3520         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " get/create thread with tid %" PRIu64,
3521                      __FUNCTION__,
3522                      GetID (),
3523                      thread_id);
3524     }
3525 
3526     // Retrieve the thread if it is already getting tracked.
3527     NativeThreadProtocolSP thread_sp = MaybeGetThreadNoLock (thread_id);
3528     if (thread_sp)
3529     {
3530         if (log)
3531             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread already tracked, returning",
3532                          __FUNCTION__,
3533                          GetID (),
3534                          thread_id);
3535         created = false;
3536         return thread_sp;
3537 
3538     }
3539 
3540     // Create the thread metadata since it isn't being tracked.
3541     if (log)
3542         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread didn't exist, tracking now",
3543                      __FUNCTION__,
3544                      GetID (),
3545                      thread_id);
3546 
3547     thread_sp.reset (new NativeThreadLinux (this, thread_id));
3548     m_threads.push_back (thread_sp);
3549     created = true;
3550 
3551     return thread_sp;
3552 }
3553 
3554 Error
3555 NativeProcessLinux::FixupBreakpointPCAsNeeded (NativeThreadProtocolSP &thread_sp)
3556 {
3557     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3558 
3559     Error error;
3560 
3561     // Get a linux thread pointer.
3562     if (!thread_sp)
3563     {
3564         error.SetErrorString ("null thread_sp");
3565         if (log)
3566             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3567         return error;
3568     }
3569     NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get());
3570 
3571     // Find out the size of a breakpoint (might depend on where we are in the code).
3572     NativeRegisterContextSP context_sp = linux_thread_p->GetRegisterContext ();
3573     if (!context_sp)
3574     {
3575         error.SetErrorString ("cannot get a NativeRegisterContext for the thread");
3576         if (log)
3577             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3578         return error;
3579     }
3580 
3581     uint32_t breakpoint_size = 0;
3582     error = GetSoftwareBreakpointSize (context_sp, breakpoint_size);
3583     if (error.Fail ())
3584     {
3585         if (log)
3586             log->Printf ("NativeProcessLinux::%s GetBreakpointSize() failed: %s", __FUNCTION__, error.AsCString ());
3587         return error;
3588     }
3589     else
3590     {
3591         if (log)
3592             log->Printf ("NativeProcessLinux::%s breakpoint size: %" PRIu32, __FUNCTION__, breakpoint_size);
3593     }
3594 
3595     // First try probing for a breakpoint at a software breakpoint location: PC - breakpoint size.
3596     const lldb::addr_t initial_pc_addr = context_sp->GetPC ();
3597     lldb::addr_t breakpoint_addr = initial_pc_addr;
3598     if (breakpoint_size > static_cast<lldb::addr_t> (0))
3599     {
3600         // Do not allow breakpoint probe to wrap around.
3601         if (breakpoint_addr >= static_cast<lldb::addr_t> (breakpoint_size))
3602             breakpoint_addr -= static_cast<lldb::addr_t> (breakpoint_size);
3603     }
3604 
3605     // Check if we stopped because of a breakpoint.
3606     NativeBreakpointSP breakpoint_sp;
3607     error = m_breakpoint_list.GetBreakpoint (breakpoint_addr, breakpoint_sp);
3608     if (!error.Success () || !breakpoint_sp)
3609     {
3610         // We didn't find one at a software probe location.  Nothing to do.
3611         if (log)
3612             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " no lldb breakpoint found at current pc with adjustment: 0x%" PRIx64, __FUNCTION__, GetID (), breakpoint_addr);
3613         return Error ();
3614     }
3615 
3616     // If the breakpoint is not a software breakpoint, nothing to do.
3617     if (!breakpoint_sp->IsSoftwareBreakpoint ())
3618     {
3619         if (log)
3620             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " breakpoint found at 0x%" PRIx64 ", not software, nothing to adjust", __FUNCTION__, GetID (), breakpoint_addr);
3621         return Error ();
3622     }
3623 
3624     //
3625     // We have a software breakpoint and need to adjust the PC.
3626     //
3627 
3628     // Sanity check.
3629     if (breakpoint_size == 0)
3630     {
3631         // Nothing to do!  How did we get here?
3632         if (log)
3633             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);
3634         return Error ();
3635     }
3636 
3637     // Change the program counter.
3638     if (log)
3639         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);
3640 
3641     error = context_sp->SetPC (breakpoint_addr);
3642     if (error.Fail ())
3643     {
3644         if (log)
3645             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": failed to set PC: %s", __FUNCTION__, GetID (), linux_thread_p->GetID (), error.AsCString ());
3646         return error;
3647     }
3648 
3649     return error;
3650 }
3651