xref: /llvm-project/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp (revision cacde7df6dc9d8c94401b7e26714dbd7383bcc15)
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 #ifndef __ANDROID__
23 #include <sys/procfs.h>
24 #endif
25 #include <sys/ptrace.h>
26 #include <sys/uio.h>
27 #include <sys/socket.h>
28 #include <sys/syscall.h>
29 #include <sys/types.h>
30 #include <sys/user.h>
31 #include <sys/wait.h>
32 
33 #if defined (__arm64__) || defined (__aarch64__)
34 // NT_PRSTATUS and NT_FPREGSET definition
35 #include <elf.h>
36 #endif
37 
38 // C++ Includes
39 #include <fstream>
40 #include <string>
41 
42 // Other libraries and framework includes
43 #include "lldb/Core/Debugger.h"
44 #include "lldb/Core/Error.h"
45 #include "lldb/Core/Module.h"
46 #include "lldb/Core/RegisterValue.h"
47 #include "lldb/Core/Scalar.h"
48 #include "lldb/Core/State.h"
49 #include "lldb/Host/Host.h"
50 #include "lldb/Host/HostInfo.h"
51 #include "lldb/Host/ThreadLauncher.h"
52 #include "lldb/Symbol/ObjectFile.h"
53 #include "lldb/Target/NativeRegisterContext.h"
54 #include "lldb/Target/ProcessLaunchInfo.h"
55 #include "lldb/Utility/PseudoTerminal.h"
56 
57 #include "Host/common/NativeBreakpoint.h"
58 #include "Utility/StringExtractor.h"
59 
60 #include "Plugins/Process/Utility/LinuxSignals.h"
61 #include "NativeThreadLinux.h"
62 #include "ProcFileReader.h"
63 #include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
64 
65 #ifdef __ANDROID__
66 #define __ptrace_request int
67 #define PT_DETACH PTRACE_DETACH
68 #endif
69 
70 #define DEBUG_PTRACE_MAXBYTES 20
71 
72 // Support ptrace extensions even when compiled without required kernel support
73 #ifndef PT_GETREGS
74 #ifndef PTRACE_GETREGS
75   #define PTRACE_GETREGS 12
76 #endif
77 #endif
78 #ifndef PT_SETREGS
79 #ifndef PTRACE_SETREGS
80   #define PTRACE_SETREGS 13
81 #endif
82 #endif
83 #ifndef PT_GETFPREGS
84 #ifndef PTRACE_GETFPREGS
85   #define PTRACE_GETFPREGS 14
86 #endif
87 #endif
88 #ifndef PT_SETFPREGS
89 #ifndef PTRACE_SETFPREGS
90   #define PTRACE_SETFPREGS 15
91 #endif
92 #endif
93 #ifndef PTRACE_GETREGSET
94   #define PTRACE_GETREGSET 0x4204
95 #endif
96 #ifndef PTRACE_SETREGSET
97   #define PTRACE_SETREGSET 0x4205
98 #endif
99 #ifndef PTRACE_GET_THREAD_AREA
100   #define PTRACE_GET_THREAD_AREA 25
101 #endif
102 #ifndef PTRACE_ARCH_PRCTL
103   #define PTRACE_ARCH_PRCTL      30
104 #endif
105 #ifndef ARCH_GET_FS
106   #define ARCH_SET_GS 0x1001
107   #define ARCH_SET_FS 0x1002
108   #define ARCH_GET_FS 0x1003
109   #define ARCH_GET_GS 0x1004
110 #endif
111 
112 #define LLDB_PERSONALITY_GET_CURRENT_SETTINGS  0xffffffff
113 
114 // Support hardware breakpoints in case it has not been defined
115 #ifndef TRAP_HWBKPT
116   #define TRAP_HWBKPT 4
117 #endif
118 
119 // Try to define a macro to encapsulate the tgkill syscall
120 // fall back on kill() if tgkill isn't available
121 #define tgkill(pid, tid, sig)  syscall(SYS_tgkill, pid, tid, sig)
122 
123 // We disable the tracing of ptrace calls for integration builds to
124 // avoid the additional indirection and checks.
125 #ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
126 #define PTRACE(req, pid, addr, data, data_size) \
127     PtraceWrapper((req), (pid), (addr), (data), (data_size), #req, __FILE__, __LINE__)
128 #else
129 #define PTRACE(req, pid, addr, data, data_size) \
130     PtraceWrapper((req), (pid), (addr), (data), (data_size))
131 #endif
132 
133 // Private bits we only need internally.
134 namespace
135 {
136     using namespace lldb;
137     using namespace lldb_private;
138 
139     const UnixSignals&
140     GetUnixSignals ()
141     {
142         static process_linux::LinuxSignals signals;
143         return signals;
144     }
145 
146     const char *
147     GetFilePath(const lldb_private::FileAction *file_action, const char *default_path)
148     {
149         const char *pts_name = "/dev/pts/";
150         const char *path = NULL;
151 
152         if (file_action)
153         {
154             if (file_action->GetAction() == FileAction::eFileActionOpen)
155             {
156                 path = file_action->GetPath ();
157                 // By default the stdio paths passed in will be pseudo-terminal
158                 // (/dev/pts). If so, convert to using a different default path
159                 // instead to redirect I/O to the debugger console. This should
160                 //  also handle user overrides to /dev/null or a different file.
161                 if (!path || ::strncmp (path, pts_name, ::strlen (pts_name)) == 0)
162                     path = default_path;
163             }
164         }
165 
166         return path;
167     }
168 
169     Error
170     ResolveProcessArchitecture (lldb::pid_t pid, Platform &platform, ArchSpec &arch)
171     {
172         // Grab process info for the running process.
173         ProcessInstanceInfo process_info;
174         if (!platform.GetProcessInfo (pid, process_info))
175             return lldb_private::Error("failed to get process info");
176 
177         // Resolve the executable module.
178         ModuleSP exe_module_sp;
179         FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths ());
180         Error error = platform.ResolveExecutable(
181             process_info.GetExecutableFile (),
182             platform.GetSystemArchitecture (),
183             exe_module_sp,
184             executable_search_paths.GetSize () ? &executable_search_paths : NULL);
185 
186         if (!error.Success ())
187             return error;
188 
189         // Check if we've got our architecture from the exe_module.
190         arch = exe_module_sp->GetArchitecture ();
191         if (arch.IsValid ())
192             return Error();
193         else
194             return Error("failed to retrieve a valid architecture from the exe module");
195     }
196 
197     void
198     DisplayBytes (lldb_private::StreamString &s, void *bytes, uint32_t count)
199     {
200         uint8_t *ptr = (uint8_t *)bytes;
201         const uint32_t loop_count = std::min<uint32_t>(DEBUG_PTRACE_MAXBYTES, count);
202         for(uint32_t i=0; i<loop_count; i++)
203         {
204             s.Printf ("[%x]", *ptr);
205             ptr++;
206         }
207     }
208 
209     void
210     PtraceDisplayBytes(int &req, void *data, size_t data_size)
211     {
212         StreamString buf;
213         Log *verbose_log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (
214                     POSIX_LOG_PTRACE | POSIX_LOG_VERBOSE));
215 
216         if (verbose_log)
217         {
218             switch(req)
219             {
220             case PTRACE_POKETEXT:
221             {
222                 DisplayBytes(buf, &data, 8);
223                 verbose_log->Printf("PTRACE_POKETEXT %s", buf.GetData());
224                 break;
225             }
226             case PTRACE_POKEDATA:
227             {
228                 DisplayBytes(buf, &data, 8);
229                 verbose_log->Printf("PTRACE_POKEDATA %s", buf.GetData());
230                 break;
231             }
232             case PTRACE_POKEUSER:
233             {
234                 DisplayBytes(buf, &data, 8);
235                 verbose_log->Printf("PTRACE_POKEUSER %s", buf.GetData());
236                 break;
237             }
238             case PTRACE_SETREGS:
239             {
240                 DisplayBytes(buf, data, data_size);
241                 verbose_log->Printf("PTRACE_SETREGS %s", buf.GetData());
242                 break;
243             }
244             case PTRACE_SETFPREGS:
245             {
246                 DisplayBytes(buf, data, data_size);
247                 verbose_log->Printf("PTRACE_SETFPREGS %s", buf.GetData());
248                 break;
249             }
250             case PTRACE_SETSIGINFO:
251             {
252                 DisplayBytes(buf, data, sizeof(siginfo_t));
253                 verbose_log->Printf("PTRACE_SETSIGINFO %s", buf.GetData());
254                 break;
255             }
256             case PTRACE_SETREGSET:
257             {
258                 // Extract iov_base from data, which is a pointer to the struct IOVEC
259                 DisplayBytes(buf, *(void **)data, data_size);
260                 verbose_log->Printf("PTRACE_SETREGSET %s", buf.GetData());
261                 break;
262             }
263             default:
264             {
265             }
266             }
267         }
268     }
269 
270     // Wrapper for ptrace to catch errors and log calls.
271     // Note that ptrace sets errno on error because -1 can be a valid result (i.e. for PTRACE_PEEK*)
272     long
273     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size,
274             const char* reqName, const char* file, int line)
275     {
276         long int result;
277 
278         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PTRACE));
279 
280         PtraceDisplayBytes(req, data, data_size);
281 
282         errno = 0;
283         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
284             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
285         else
286             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
287 
288         if (log)
289             log->Printf("ptrace(%s, %" PRIu64 ", %p, %p, %zu)=%lX called from file %s line %d",
290                     reqName, pid, addr, data, data_size, result, file, line);
291 
292         PtraceDisplayBytes(req, data, data_size);
293 
294         if (log && errno != 0)
295         {
296             const char* str;
297             switch (errno)
298             {
299             case ESRCH:  str = "ESRCH"; break;
300             case EINVAL: str = "EINVAL"; break;
301             case EBUSY:  str = "EBUSY"; break;
302             case EPERM:  str = "EPERM"; break;
303             default:     str = "<unknown>";
304             }
305             log->Printf("ptrace() failed; errno=%d (%s)", errno, str);
306         }
307 
308         return result;
309     }
310 
311 #ifdef LLDB_CONFIGURATION_BUILDANDINTEGRATION
312     // Wrapper for ptrace when logging is not required.
313     // Sets errno to 0 prior to calling ptrace.
314     long
315     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size)
316     {
317         long result = 0;
318         errno = 0;
319         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
320             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
321         else
322             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
323         return result;
324     }
325 #endif
326 
327     //------------------------------------------------------------------------------
328     // Static implementations of NativeProcessLinux::ReadMemory and
329     // NativeProcessLinux::WriteMemory.  This enables mutual recursion between these
330     // functions without needed to go thru the thread funnel.
331 
332     static lldb::addr_t
333     DoReadMemory (
334         lldb::pid_t pid,
335         lldb::addr_t vm_addr,
336         void *buf,
337         lldb::addr_t size,
338         Error &error)
339     {
340         // ptrace word size is determined by the host, not the child
341         static const unsigned word_size = sizeof(void*);
342         unsigned char *dst = static_cast<unsigned char*>(buf);
343         lldb::addr_t bytes_read;
344         lldb::addr_t remainder;
345         long data;
346 
347         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
348         if (log)
349             ProcessPOSIXLog::IncNestLevel();
350         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
351             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %d, %p, %p, %zd, _)", __FUNCTION__,
352                     pid, word_size, (void*)vm_addr, buf, size);
353 
354         assert(sizeof(data) >= word_size);
355         for (bytes_read = 0; bytes_read < size; bytes_read += remainder)
356         {
357             errno = 0;
358             data = PTRACE(PTRACE_PEEKDATA, pid, (void*)vm_addr, NULL, 0);
359             if (errno)
360             {
361                 error.SetErrorToErrno();
362                 if (log)
363                     ProcessPOSIXLog::DecNestLevel();
364                 return bytes_read;
365             }
366 
367             remainder = size - bytes_read;
368             remainder = remainder > word_size ? word_size : remainder;
369 
370             // Copy the data into our buffer
371             for (unsigned i = 0; i < remainder; ++i)
372                 dst[i] = ((data >> i*8) & 0xFF);
373 
374             if (log && ProcessPOSIXLog::AtTopNestLevel() &&
375                     (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
376                             (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
377                                     size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
378             {
379                 uintptr_t print_dst = 0;
380                 // Format bytes from data by moving into print_dst for log output
381                 for (unsigned i = 0; i < remainder; ++i)
382                     print_dst |= (((data >> i*8) & 0xFF) << i*8);
383                 log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
384                         (void*)vm_addr, print_dst, (unsigned long)data);
385             }
386 
387             vm_addr += word_size;
388             dst += word_size;
389         }
390 
391         if (log)
392             ProcessPOSIXLog::DecNestLevel();
393         return bytes_read;
394     }
395 
396     static lldb::addr_t
397     DoWriteMemory(
398         lldb::pid_t pid,
399         lldb::addr_t vm_addr,
400         const void *buf,
401         lldb::addr_t size,
402         Error &error)
403     {
404         // ptrace word size is determined by the host, not the child
405         static const unsigned word_size = sizeof(void*);
406         const unsigned char *src = static_cast<const unsigned char*>(buf);
407         lldb::addr_t bytes_written = 0;
408         lldb::addr_t remainder;
409 
410         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
411         if (log)
412             ProcessPOSIXLog::IncNestLevel();
413         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
414             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %u, %p, %p, %" PRIu64 ")", __FUNCTION__,
415                     pid, word_size, (void*)vm_addr, buf, size);
416 
417         for (bytes_written = 0; bytes_written < size; bytes_written += remainder)
418         {
419             remainder = size - bytes_written;
420             remainder = remainder > word_size ? word_size : remainder;
421 
422             if (remainder == word_size)
423             {
424                 unsigned long data = 0;
425                 assert(sizeof(data) >= word_size);
426                 for (unsigned i = 0; i < word_size; ++i)
427                     data |= (unsigned long)src[i] << i*8;
428 
429                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
430                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
431                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
432                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
433                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
434                             (void*)vm_addr, *(unsigned long*)src, data);
435 
436                 if (PTRACE(PTRACE_POKEDATA, pid, (void*)vm_addr, (void*)data, 0))
437                 {
438                     error.SetErrorToErrno();
439                     if (log)
440                         ProcessPOSIXLog::DecNestLevel();
441                     return bytes_written;
442                 }
443             }
444             else
445             {
446                 unsigned char buff[8];
447                 if (DoReadMemory(pid, vm_addr,
448                                 buff, word_size, error) != word_size)
449                 {
450                     if (log)
451                         ProcessPOSIXLog::DecNestLevel();
452                     return bytes_written;
453                 }
454 
455                 memcpy(buff, src, remainder);
456 
457                 if (DoWriteMemory(pid, vm_addr,
458                                 buff, word_size, error) != word_size)
459                 {
460                     if (log)
461                         ProcessPOSIXLog::DecNestLevel();
462                     return bytes_written;
463                 }
464 
465                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
466                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
467                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
468                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
469                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
470                             (void*)vm_addr, *(unsigned long*)src, *(unsigned long*)buff);
471             }
472 
473             vm_addr += word_size;
474             src += word_size;
475         }
476         if (log)
477             ProcessPOSIXLog::DecNestLevel();
478         return bytes_written;
479     }
480 
481     //------------------------------------------------------------------------------
482     /// @class Operation
483     /// @brief Represents a NativeProcessLinux operation.
484     ///
485     /// Under Linux, it is not possible to ptrace() from any other thread but the
486     /// one that spawned or attached to the process from the start.  Therefore, when
487     /// a NativeProcessLinux is asked to deliver or change the state of an inferior
488     /// process the operation must be "funneled" to a specific thread to perform the
489     /// task.  The Operation class provides an abstract base for all services the
490     /// NativeProcessLinux must perform via the single virtual function Execute, thus
491     /// encapsulating the code that needs to run in the privileged context.
492     class Operation
493     {
494     public:
495         Operation () : m_error() { }
496 
497         virtual
498         ~Operation() {}
499 
500         virtual void
501         Execute (NativeProcessLinux *process) = 0;
502 
503         const Error &
504         GetError () const { return m_error; }
505 
506     protected:
507         Error m_error;
508     };
509 
510     //------------------------------------------------------------------------------
511     /// @class ReadOperation
512     /// @brief Implements NativeProcessLinux::ReadMemory.
513     class ReadOperation : public Operation
514     {
515     public:
516         ReadOperation (
517             lldb::addr_t addr,
518             void *buff,
519             lldb::addr_t size,
520             lldb::addr_t &result) :
521             Operation (),
522             m_addr (addr),
523             m_buff (buff),
524             m_size (size),
525             m_result (result)
526             {
527             }
528 
529         void Execute (NativeProcessLinux *process) override;
530 
531     private:
532         lldb::addr_t m_addr;
533         void *m_buff;
534         lldb::addr_t m_size;
535         lldb::addr_t &m_result;
536     };
537 
538     void
539     ReadOperation::Execute (NativeProcessLinux *process)
540     {
541         m_result = DoReadMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
542     }
543 
544     //------------------------------------------------------------------------------
545     /// @class WriteOperation
546     /// @brief Implements NativeProcessLinux::WriteMemory.
547     class WriteOperation : public Operation
548     {
549     public:
550         WriteOperation (
551             lldb::addr_t addr,
552             const void *buff,
553             lldb::addr_t size,
554             lldb::addr_t &result) :
555             Operation (),
556             m_addr (addr),
557             m_buff (buff),
558             m_size (size),
559             m_result (result)
560             {
561             }
562 
563         void Execute (NativeProcessLinux *process) override;
564 
565     private:
566         lldb::addr_t m_addr;
567         const void *m_buff;
568         lldb::addr_t m_size;
569         lldb::addr_t &m_result;
570     };
571 
572     void
573     WriteOperation::Execute(NativeProcessLinux *process)
574     {
575         m_result = DoWriteMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
576     }
577 
578     //------------------------------------------------------------------------------
579     /// @class ReadRegOperation
580     /// @brief Implements NativeProcessLinux::ReadRegisterValue.
581     class ReadRegOperation : public Operation
582     {
583     public:
584         ReadRegOperation(lldb::tid_t tid, uint32_t offset, const char *reg_name,
585                 RegisterValue &value, bool &result)
586             : m_tid(tid), m_offset(static_cast<uintptr_t> (offset)), m_reg_name(reg_name),
587               m_value(value), m_result(result)
588             { }
589 
590         void Execute(NativeProcessLinux *monitor);
591 
592     private:
593         lldb::tid_t m_tid;
594         uintptr_t m_offset;
595         const char *m_reg_name;
596         RegisterValue &m_value;
597         bool &m_result;
598     };
599 
600     void
601     ReadRegOperation::Execute(NativeProcessLinux *monitor)
602     {
603 #if defined (__arm64__) || defined (__aarch64__)
604         if (m_offset > sizeof(struct user_pt_regs))
605         {
606             uintptr_t offset = m_offset - sizeof(struct user_pt_regs);
607             if (offset > sizeof(struct user_fpsimd_state))
608             {
609                 m_result = false;
610             }
611             else
612             {
613                 elf_fpregset_t regs;
614                 int regset = NT_FPREGSET;
615                 struct iovec ioVec;
616 
617                 ioVec.iov_base = &regs;
618                 ioVec.iov_len = sizeof regs;
619                 if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
620                     m_result = false;
621                 else
622                 {
623                     lldb_private::ArchSpec arch;
624                     if (monitor->GetArchitecture(arch))
625                     {
626                         m_result = true;
627                         m_value.SetBytes((void *)(((unsigned char *)(&regs)) + offset), 16, arch.GetByteOrder());
628                     }
629                     else
630                         m_result = false;
631                 }
632             }
633         }
634         else
635         {
636             elf_gregset_t regs;
637             int regset = NT_PRSTATUS;
638             struct iovec ioVec;
639 
640             ioVec.iov_base = &regs;
641             ioVec.iov_len = sizeof regs;
642             if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
643                 m_result = false;
644             else
645             {
646                 lldb_private::ArchSpec arch;
647                 if (monitor->GetArchitecture(arch))
648                 {
649                     m_result = true;
650                     m_value.SetBytes((void *)(((unsigned char *)(regs)) + m_offset), 8, arch.GetByteOrder());
651                 } else
652                     m_result = false;
653             }
654         }
655 #else
656         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
657 
658         // Set errno to zero so that we can detect a failed peek.
659         errno = 0;
660         lldb::addr_t data = PTRACE(PTRACE_PEEKUSER, m_tid, (void*)m_offset, NULL, 0);
661         if (errno)
662             m_result = false;
663         else
664         {
665             m_value = data;
666             m_result = true;
667         }
668         if (log)
669             log->Printf ("NativeProcessLinux::%s() reg %s: 0x%" PRIx64, __FUNCTION__,
670                     m_reg_name, data);
671 #endif
672     }
673 
674     //------------------------------------------------------------------------------
675     /// @class WriteRegOperation
676     /// @brief Implements NativeProcessLinux::WriteRegisterValue.
677     class WriteRegOperation : public Operation
678     {
679     public:
680         WriteRegOperation(lldb::tid_t tid, unsigned offset, const char *reg_name,
681                 const RegisterValue &value, bool &result)
682             : m_tid(tid), m_offset(offset), m_reg_name(reg_name),
683               m_value(value), m_result(result)
684             { }
685 
686         void Execute(NativeProcessLinux *monitor);
687 
688     private:
689         lldb::tid_t m_tid;
690         uintptr_t m_offset;
691         const char *m_reg_name;
692         const RegisterValue &m_value;
693         bool &m_result;
694     };
695 
696     void
697     WriteRegOperation::Execute(NativeProcessLinux *monitor)
698     {
699 #if defined (__arm64__) || defined (__aarch64__)
700         if (m_offset > sizeof(struct user_pt_regs))
701         {
702             uintptr_t offset = m_offset - sizeof(struct user_pt_regs);
703             if (offset > sizeof(struct user_fpsimd_state))
704             {
705                 m_result = false;
706             }
707             else
708             {
709                 elf_fpregset_t regs;
710                 int regset = NT_FPREGSET;
711                 struct iovec ioVec;
712 
713                 ioVec.iov_base = &regs;
714                 ioVec.iov_len = sizeof regs;
715                 if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
716                     m_result = false;
717                 else
718                 {
719                     ::memcpy((void *)(((unsigned char *)(&regs)) + offset), m_value.GetBytes(), 16);
720                     if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
721                         m_result = false;
722                     else
723                         m_result = true;
724                 }
725             }
726         }
727         else
728         {
729             elf_gregset_t regs;
730             int regset = NT_PRSTATUS;
731             struct iovec ioVec;
732 
733             ioVec.iov_base = &regs;
734             ioVec.iov_len = sizeof regs;
735             if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
736                 m_result = false;
737             else
738             {
739                 ::memcpy((void *)(((unsigned char *)(&regs)) + m_offset), m_value.GetBytes(), 8);
740                 if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
741                     m_result = false;
742                 else
743                     m_result = true;
744             }
745         }
746 #else
747         void* buf;
748         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
749 
750         buf = (void*) m_value.GetAsUInt64();
751 
752         if (log)
753             log->Printf ("NativeProcessLinux::%s() reg %s: %p", __FUNCTION__, m_reg_name, buf);
754         if (PTRACE(PTRACE_POKEUSER, m_tid, (void*)m_offset, buf, 0))
755             m_result = false;
756         else
757             m_result = true;
758 #endif
759     }
760 
761     //------------------------------------------------------------------------------
762     /// @class ReadGPROperation
763     /// @brief Implements NativeProcessLinux::ReadGPR.
764     class ReadGPROperation : public Operation
765     {
766     public:
767         ReadGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
768             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
769             { }
770 
771         void Execute(NativeProcessLinux *monitor);
772 
773     private:
774         lldb::tid_t m_tid;
775         void *m_buf;
776         size_t m_buf_size;
777         bool &m_result;
778     };
779 
780     void
781     ReadGPROperation::Execute(NativeProcessLinux *monitor)
782     {
783 #if defined (__arm64__) || defined (__aarch64__)
784         int regset = NT_PRSTATUS;
785         struct iovec ioVec;
786 
787         ioVec.iov_base = m_buf;
788         ioVec.iov_len = m_buf_size;
789         if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
790             m_result = false;
791         else
792             m_result = true;
793 #else
794         if (PTRACE(PTRACE_GETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
795             m_result = false;
796         else
797             m_result = true;
798 #endif
799     }
800 
801     //------------------------------------------------------------------------------
802     /// @class ReadFPROperation
803     /// @brief Implements NativeProcessLinux::ReadFPR.
804     class ReadFPROperation : public Operation
805     {
806     public:
807         ReadFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
808             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
809             { }
810 
811         void Execute(NativeProcessLinux *monitor);
812 
813     private:
814         lldb::tid_t m_tid;
815         void *m_buf;
816         size_t m_buf_size;
817         bool &m_result;
818     };
819 
820     void
821     ReadFPROperation::Execute(NativeProcessLinux *monitor)
822     {
823 #if defined (__arm64__) || defined (__aarch64__)
824         int regset = NT_FPREGSET;
825         struct iovec ioVec;
826 
827         ioVec.iov_base = m_buf;
828         ioVec.iov_len = m_buf_size;
829         if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
830             m_result = false;
831         else
832             m_result = true;
833 #else
834         if (PTRACE(PTRACE_GETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
835             m_result = false;
836         else
837             m_result = true;
838 #endif
839     }
840 
841     //------------------------------------------------------------------------------
842     /// @class ReadRegisterSetOperation
843     /// @brief Implements NativeProcessLinux::ReadRegisterSet.
844     class ReadRegisterSetOperation : public Operation
845     {
846     public:
847         ReadRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
848             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
849             { }
850 
851         void Execute(NativeProcessLinux *monitor);
852 
853     private:
854         lldb::tid_t m_tid;
855         void *m_buf;
856         size_t m_buf_size;
857         const unsigned int m_regset;
858         bool &m_result;
859     };
860 
861     void
862     ReadRegisterSetOperation::Execute(NativeProcessLinux *monitor)
863     {
864         if (PTRACE(PTRACE_GETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
865             m_result = false;
866         else
867             m_result = true;
868     }
869 
870     //------------------------------------------------------------------------------
871     /// @class WriteGPROperation
872     /// @brief Implements NativeProcessLinux::WriteGPR.
873     class WriteGPROperation : public Operation
874     {
875     public:
876         WriteGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
877             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
878             { }
879 
880         void Execute(NativeProcessLinux *monitor);
881 
882     private:
883         lldb::tid_t m_tid;
884         void *m_buf;
885         size_t m_buf_size;
886         bool &m_result;
887     };
888 
889     void
890     WriteGPROperation::Execute(NativeProcessLinux *monitor)
891     {
892 #if defined (__arm64__) || defined (__aarch64__)
893         int regset = NT_PRSTATUS;
894         struct iovec ioVec;
895 
896         ioVec.iov_base = m_buf;
897         ioVec.iov_len = m_buf_size;
898         if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
899             m_result = false;
900         else
901             m_result = true;
902 #else
903         if (PTRACE(PTRACE_SETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
904             m_result = false;
905         else
906             m_result = true;
907 #endif
908     }
909 
910     //------------------------------------------------------------------------------
911     /// @class WriteFPROperation
912     /// @brief Implements NativeProcessLinux::WriteFPR.
913     class WriteFPROperation : public Operation
914     {
915     public:
916         WriteFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
917             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
918             { }
919 
920         void Execute(NativeProcessLinux *monitor);
921 
922     private:
923         lldb::tid_t m_tid;
924         void *m_buf;
925         size_t m_buf_size;
926         bool &m_result;
927     };
928 
929     void
930     WriteFPROperation::Execute(NativeProcessLinux *monitor)
931     {
932 #if defined (__arm64__) || defined (__aarch64__)
933         int regset = NT_FPREGSET;
934         struct iovec ioVec;
935 
936         ioVec.iov_base = m_buf;
937         ioVec.iov_len = m_buf_size;
938         if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
939             m_result = false;
940         else
941             m_result = true;
942 #else
943         if (PTRACE(PTRACE_SETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
944             m_result = false;
945         else
946             m_result = true;
947 #endif
948     }
949 
950     //------------------------------------------------------------------------------
951     /// @class WriteRegisterSetOperation
952     /// @brief Implements NativeProcessLinux::WriteRegisterSet.
953     class WriteRegisterSetOperation : public Operation
954     {
955     public:
956         WriteRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
957             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
958             { }
959 
960         void Execute(NativeProcessLinux *monitor);
961 
962     private:
963         lldb::tid_t m_tid;
964         void *m_buf;
965         size_t m_buf_size;
966         const unsigned int m_regset;
967         bool &m_result;
968     };
969 
970     void
971     WriteRegisterSetOperation::Execute(NativeProcessLinux *monitor)
972     {
973         if (PTRACE(PTRACE_SETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
974             m_result = false;
975         else
976             m_result = true;
977     }
978 
979     //------------------------------------------------------------------------------
980     /// @class ResumeOperation
981     /// @brief Implements NativeProcessLinux::Resume.
982     class ResumeOperation : public Operation
983     {
984     public:
985         ResumeOperation(lldb::tid_t tid, uint32_t signo, bool &result) :
986             m_tid(tid), m_signo(signo), m_result(result) { }
987 
988         void Execute(NativeProcessLinux *monitor);
989 
990     private:
991         lldb::tid_t m_tid;
992         uint32_t m_signo;
993         bool &m_result;
994     };
995 
996     void
997     ResumeOperation::Execute(NativeProcessLinux *monitor)
998     {
999         intptr_t data = 0;
1000 
1001         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
1002             data = m_signo;
1003 
1004         if (PTRACE(PTRACE_CONT, m_tid, NULL, (void*)data, 0))
1005         {
1006             Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1007 
1008             if (log)
1009                 log->Printf ("ResumeOperation (%"  PRIu64 ") failed: %s", m_tid, strerror(errno));
1010             m_result = false;
1011         }
1012         else
1013             m_result = true;
1014     }
1015 
1016     //------------------------------------------------------------------------------
1017     /// @class SingleStepOperation
1018     /// @brief Implements NativeProcessLinux::SingleStep.
1019     class SingleStepOperation : public Operation
1020     {
1021     public:
1022         SingleStepOperation(lldb::tid_t tid, uint32_t signo, bool &result)
1023             : m_tid(tid), m_signo(signo), m_result(result) { }
1024 
1025         void Execute(NativeProcessLinux *monitor);
1026 
1027     private:
1028         lldb::tid_t m_tid;
1029         uint32_t m_signo;
1030         bool &m_result;
1031     };
1032 
1033     void
1034     SingleStepOperation::Execute(NativeProcessLinux *monitor)
1035     {
1036         intptr_t data = 0;
1037 
1038         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
1039             data = m_signo;
1040 
1041         if (PTRACE(PTRACE_SINGLESTEP, m_tid, NULL, (void*)data, 0))
1042             m_result = false;
1043         else
1044             m_result = true;
1045     }
1046 
1047     //------------------------------------------------------------------------------
1048     /// @class SiginfoOperation
1049     /// @brief Implements NativeProcessLinux::GetSignalInfo.
1050     class SiginfoOperation : public Operation
1051     {
1052     public:
1053         SiginfoOperation(lldb::tid_t tid, void *info, bool &result, int &ptrace_err)
1054             : m_tid(tid), m_info(info), m_result(result), m_err(ptrace_err) { }
1055 
1056         void Execute(NativeProcessLinux *monitor);
1057 
1058     private:
1059         lldb::tid_t m_tid;
1060         void *m_info;
1061         bool &m_result;
1062         int &m_err;
1063     };
1064 
1065     void
1066     SiginfoOperation::Execute(NativeProcessLinux *monitor)
1067     {
1068         if (PTRACE(PTRACE_GETSIGINFO, m_tid, NULL, m_info, 0)) {
1069             m_result = false;
1070             m_err = errno;
1071         }
1072         else
1073             m_result = true;
1074     }
1075 
1076     //------------------------------------------------------------------------------
1077     /// @class EventMessageOperation
1078     /// @brief Implements NativeProcessLinux::GetEventMessage.
1079     class EventMessageOperation : public Operation
1080     {
1081     public:
1082         EventMessageOperation(lldb::tid_t tid, unsigned long *message, bool &result)
1083             : m_tid(tid), m_message(message), m_result(result) { }
1084 
1085         void Execute(NativeProcessLinux *monitor);
1086 
1087     private:
1088         lldb::tid_t m_tid;
1089         unsigned long *m_message;
1090         bool &m_result;
1091     };
1092 
1093     void
1094     EventMessageOperation::Execute(NativeProcessLinux *monitor)
1095     {
1096         if (PTRACE(PTRACE_GETEVENTMSG, m_tid, NULL, m_message, 0))
1097             m_result = false;
1098         else
1099             m_result = true;
1100     }
1101 
1102     class DetachOperation : public Operation
1103     {
1104     public:
1105         DetachOperation(lldb::tid_t tid, Error &result) : m_tid(tid), m_error(result) { }
1106 
1107         void Execute(NativeProcessLinux *monitor);
1108 
1109     private:
1110         lldb::tid_t m_tid;
1111         Error &m_error;
1112     };
1113 
1114     void
1115     DetachOperation::Execute(NativeProcessLinux *monitor)
1116     {
1117         if (ptrace(PT_DETACH, m_tid, NULL, 0) < 0)
1118             m_error.SetErrorToErrno();
1119     }
1120 
1121 }
1122 
1123 using namespace lldb_private;
1124 
1125 // Simple helper function to ensure flags are enabled on the given file
1126 // descriptor.
1127 static bool
1128 EnsureFDFlags(int fd, int flags, Error &error)
1129 {
1130     int status;
1131 
1132     if ((status = fcntl(fd, F_GETFL)) == -1)
1133     {
1134         error.SetErrorToErrno();
1135         return false;
1136     }
1137 
1138     if (fcntl(fd, F_SETFL, status | flags) == -1)
1139     {
1140         error.SetErrorToErrno();
1141         return false;
1142     }
1143 
1144     return true;
1145 }
1146 
1147 NativeProcessLinux::OperationArgs::OperationArgs(NativeProcessLinux *monitor)
1148     : m_monitor(monitor)
1149 {
1150     sem_init(&m_semaphore, 0, 0);
1151 }
1152 
1153 NativeProcessLinux::OperationArgs::~OperationArgs()
1154 {
1155     sem_destroy(&m_semaphore);
1156 }
1157 
1158 NativeProcessLinux::LaunchArgs::LaunchArgs(NativeProcessLinux *monitor,
1159                                        lldb_private::Module *module,
1160                                        char const **argv,
1161                                        char const **envp,
1162                                        const char *stdin_path,
1163                                        const char *stdout_path,
1164                                        const char *stderr_path,
1165                                        const char *working_dir,
1166                                        const lldb_private::ProcessLaunchInfo &launch_info)
1167     : OperationArgs(monitor),
1168       m_module(module),
1169       m_argv(argv),
1170       m_envp(envp),
1171       m_stdin_path(stdin_path),
1172       m_stdout_path(stdout_path),
1173       m_stderr_path(stderr_path),
1174       m_working_dir(working_dir),
1175       m_launch_info(launch_info)
1176 {
1177 }
1178 
1179 NativeProcessLinux::LaunchArgs::~LaunchArgs()
1180 { }
1181 
1182 NativeProcessLinux::AttachArgs::AttachArgs(NativeProcessLinux *monitor,
1183                                        lldb::pid_t pid)
1184     : OperationArgs(monitor), m_pid(pid) { }
1185 
1186 NativeProcessLinux::AttachArgs::~AttachArgs()
1187 { }
1188 
1189 // -----------------------------------------------------------------------------
1190 // Public Static Methods
1191 // -----------------------------------------------------------------------------
1192 
1193 lldb_private::Error
1194 NativeProcessLinux::LaunchProcess (
1195     lldb_private::Module *exe_module,
1196     lldb_private::ProcessLaunchInfo &launch_info,
1197     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1198     NativeProcessProtocolSP &native_process_sp)
1199 {
1200     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1201 
1202     Error error;
1203 
1204     // Verify the working directory is valid if one was specified.
1205     const char* working_dir = launch_info.GetWorkingDirectory ();
1206     if (working_dir)
1207     {
1208       FileSpec working_dir_fs (working_dir, true);
1209       if (!working_dir_fs || working_dir_fs.GetFileType () != FileSpec::eFileTypeDirectory)
1210       {
1211           error.SetErrorStringWithFormat ("No such file or directory: %s", working_dir);
1212           return error;
1213       }
1214     }
1215 
1216     const lldb_private::FileAction *file_action;
1217 
1218     // Default of NULL will mean to use existing open file descriptors.
1219     const char *stdin_path = NULL;
1220     const char *stdout_path = NULL;
1221     const char *stderr_path = NULL;
1222 
1223     file_action = launch_info.GetFileActionForFD (STDIN_FILENO);
1224     stdin_path = GetFilePath (file_action, stdin_path);
1225 
1226     file_action = launch_info.GetFileActionForFD (STDOUT_FILENO);
1227     stdout_path = GetFilePath (file_action, stdout_path);
1228 
1229     file_action = launch_info.GetFileActionForFD (STDERR_FILENO);
1230     stderr_path = GetFilePath (file_action, stderr_path);
1231 
1232     // Create the NativeProcessLinux in launch mode.
1233     native_process_sp.reset (new NativeProcessLinux ());
1234 
1235     if (log)
1236     {
1237         int i = 0;
1238         for (const char **args = launch_info.GetArguments ().GetConstArgumentVector (); *args; ++args, ++i)
1239         {
1240             log->Printf ("NativeProcessLinux::%s arg %d: \"%s\"", __FUNCTION__, i, *args ? *args : "nullptr");
1241             ++i;
1242         }
1243     }
1244 
1245     if (!native_process_sp->RegisterNativeDelegate (native_delegate))
1246     {
1247         native_process_sp.reset ();
1248         error.SetErrorStringWithFormat ("failed to register the native delegate");
1249         return error;
1250     }
1251 
1252     reinterpret_cast<NativeProcessLinux*> (native_process_sp.get ())->LaunchInferior (
1253             exe_module,
1254             launch_info.GetArguments ().GetConstArgumentVector (),
1255             launch_info.GetEnvironmentEntries ().GetConstArgumentVector (),
1256             stdin_path,
1257             stdout_path,
1258             stderr_path,
1259             working_dir,
1260             launch_info,
1261             error);
1262 
1263     if (error.Fail ())
1264     {
1265         native_process_sp.reset ();
1266         if (log)
1267             log->Printf ("NativeProcessLinux::%s failed to launch process: %s", __FUNCTION__, error.AsCString ());
1268         return error;
1269     }
1270 
1271     launch_info.SetProcessID (native_process_sp->GetID ());
1272 
1273     return error;
1274 }
1275 
1276 lldb_private::Error
1277 NativeProcessLinux::AttachToProcess (
1278     lldb::pid_t pid,
1279     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1280     NativeProcessProtocolSP &native_process_sp)
1281 {
1282     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1283     if (log && log->GetMask ().Test (POSIX_LOG_VERBOSE))
1284         log->Printf ("NativeProcessLinux::%s(pid = %" PRIi64 ")", __FUNCTION__, pid);
1285 
1286     // Grab the current platform architecture.  This should be Linux,
1287     // since this code is only intended to run on a Linux host.
1288     PlatformSP platform_sp (Platform::GetHostPlatform ());
1289     if (!platform_sp)
1290         return Error("failed to get a valid default platform");
1291 
1292     // Retrieve the architecture for the running process.
1293     ArchSpec process_arch;
1294     Error error = ResolveProcessArchitecture (pid, *platform_sp.get (), process_arch);
1295     if (!error.Success ())
1296         return error;
1297 
1298     native_process_sp.reset (new NativeProcessLinux ());
1299 
1300     if (!native_process_sp->RegisterNativeDelegate (native_delegate))
1301     {
1302         native_process_sp.reset (new NativeProcessLinux ());
1303         error.SetErrorStringWithFormat ("failed to register the native delegate");
1304         return error;
1305     }
1306 
1307     reinterpret_cast<NativeProcessLinux*> (native_process_sp.get ())->AttachToInferior (pid, error);
1308     if (!error.Success ())
1309     {
1310         native_process_sp.reset ();
1311         return error;
1312     }
1313 
1314     return error;
1315 }
1316 
1317 // -----------------------------------------------------------------------------
1318 // Public Instance Methods
1319 // -----------------------------------------------------------------------------
1320 
1321 NativeProcessLinux::NativeProcessLinux () :
1322     NativeProcessProtocol (LLDB_INVALID_PROCESS_ID),
1323     m_arch (),
1324     m_operation (nullptr),
1325     m_operation_mutex (),
1326     m_operation_pending (),
1327     m_operation_done (),
1328     m_wait_for_stop_tids (),
1329     m_wait_for_stop_tids_mutex (),
1330     m_wait_for_group_stop_tids (),
1331     m_group_stop_signal_tid (LLDB_INVALID_THREAD_ID),
1332     m_group_stop_signal (LLDB_INVALID_SIGNAL_NUMBER),
1333     m_wait_for_group_stop_tids_mutex (),
1334     m_supports_mem_region (eLazyBoolCalculate),
1335     m_mem_region_cache (),
1336     m_mem_region_cache_mutex ()
1337 {
1338 }
1339 
1340 //------------------------------------------------------------------------------
1341 /// The basic design of the NativeProcessLinux is built around two threads.
1342 ///
1343 /// One thread (@see SignalThread) simply blocks on a call to waitpid() looking
1344 /// for changes in the debugee state.  When a change is detected a
1345 /// ProcessMessage is sent to the associated ProcessLinux instance.  This thread
1346 /// "drives" state changes in the debugger.
1347 ///
1348 /// The second thread (@see OperationThread) is responsible for two things 1)
1349 /// launching or attaching to the inferior process, and then 2) servicing
1350 /// operations such as register reads/writes, stepping, etc.  See the comments
1351 /// on the Operation class for more info as to why this is needed.
1352 void
1353 NativeProcessLinux::LaunchInferior (
1354     Module *module,
1355     const char *argv[],
1356     const char *envp[],
1357     const char *stdin_path,
1358     const char *stdout_path,
1359     const char *stderr_path,
1360     const char *working_dir,
1361     const lldb_private::ProcessLaunchInfo &launch_info,
1362     lldb_private::Error &error)
1363 {
1364     if (module)
1365         m_arch = module->GetArchitecture ();
1366 
1367     SetState(eStateLaunching);
1368 
1369     std::unique_ptr<LaunchArgs> args(
1370         new LaunchArgs(
1371             this, module, argv, envp,
1372             stdin_path, stdout_path, stderr_path,
1373             working_dir, launch_info));
1374 
1375     sem_init(&m_operation_pending, 0, 0);
1376     sem_init(&m_operation_done, 0, 0);
1377 
1378     StartLaunchOpThread(args.get(), error);
1379     if (!error.Success())
1380         return;
1381 
1382 WAIT_AGAIN:
1383     // Wait for the operation thread to initialize.
1384     if (sem_wait(&args->m_semaphore))
1385     {
1386         if (errno == EINTR)
1387             goto WAIT_AGAIN;
1388         else
1389         {
1390             error.SetErrorToErrno();
1391             return;
1392         }
1393     }
1394 
1395     // Check that the launch was a success.
1396     if (!args->m_error.Success())
1397     {
1398         StopOpThread();
1399         error = args->m_error;
1400         return;
1401     }
1402 
1403     // Finally, start monitoring the child process for change in state.
1404     m_monitor_thread = Host::StartMonitoringChildProcess(
1405         NativeProcessLinux::MonitorCallback, this, GetID(), true);
1406     if (!m_monitor_thread.IsJoinable())
1407     {
1408         error.SetErrorToGenericError();
1409         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1410         return;
1411     }
1412 }
1413 
1414 void
1415 NativeProcessLinux::AttachToInferior (lldb::pid_t pid, lldb_private::Error &error)
1416 {
1417     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1418     if (log)
1419         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ")", __FUNCTION__, pid);
1420 
1421     // We can use the Host for everything except the ResolveExecutable portion.
1422     PlatformSP platform_sp = Platform::GetHostPlatform ();
1423     if (!platform_sp)
1424     {
1425         if (log)
1426             log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 "): no default platform set", __FUNCTION__, pid);
1427         error.SetErrorString ("no default platform available");
1428     }
1429 
1430     // Gather info about the process.
1431     ProcessInstanceInfo process_info;
1432     platform_sp->GetProcessInfo (pid, process_info);
1433 
1434     // Resolve the executable module
1435     ModuleSP exe_module_sp;
1436     FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths());
1437 
1438     error = platform_sp->ResolveExecutable(process_info.GetExecutableFile(), HostInfo::GetArchitecture(), exe_module_sp,
1439                                            executable_search_paths.GetSize() ? &executable_search_paths : NULL);
1440     if (!error.Success())
1441         return;
1442 
1443     // Set the architecture to the exe architecture.
1444     m_arch = exe_module_sp->GetArchitecture();
1445     if (log)
1446         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ") detected architecture %s", __FUNCTION__, pid, m_arch.GetArchitectureName ());
1447 
1448     m_pid = pid;
1449     SetState(eStateAttaching);
1450 
1451     sem_init (&m_operation_pending, 0, 0);
1452     sem_init (&m_operation_done, 0, 0);
1453 
1454     std::unique_ptr<AttachArgs> args (new AttachArgs (this, pid));
1455 
1456     StartAttachOpThread(args.get (), error);
1457     if (!error.Success ())
1458         return;
1459 
1460 WAIT_AGAIN:
1461     // Wait for the operation thread to initialize.
1462     if (sem_wait (&args->m_semaphore))
1463     {
1464         if (errno == EINTR)
1465             goto WAIT_AGAIN;
1466         else
1467         {
1468             error.SetErrorToErrno ();
1469             return;
1470         }
1471     }
1472 
1473     // Check that the attach was a success.
1474     if (!args->m_error.Success ())
1475     {
1476         StopOpThread ();
1477         error = args->m_error;
1478         return;
1479     }
1480 
1481     // Finally, start monitoring the child process for change in state.
1482     m_monitor_thread = Host::StartMonitoringChildProcess (
1483         NativeProcessLinux::MonitorCallback, this, GetID (), true);
1484     if (!m_monitor_thread.IsJoinable())
1485     {
1486         error.SetErrorToGenericError ();
1487         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1488         return;
1489     }
1490 }
1491 
1492 NativeProcessLinux::~NativeProcessLinux()
1493 {
1494     StopMonitor();
1495 }
1496 
1497 //------------------------------------------------------------------------------
1498 // Thread setup and tear down.
1499 
1500 void
1501 NativeProcessLinux::StartLaunchOpThread(LaunchArgs *args, Error &error)
1502 {
1503     static const char *g_thread_name = "lldb.process.nativelinux.operation";
1504 
1505     if (m_operation_thread.IsJoinable())
1506         return;
1507 
1508     m_operation_thread = ThreadLauncher::LaunchThread(g_thread_name, LaunchOpThread, args, &error);
1509 }
1510 
1511 void *
1512 NativeProcessLinux::LaunchOpThread(void *arg)
1513 {
1514     LaunchArgs *args = static_cast<LaunchArgs*>(arg);
1515 
1516     if (!Launch(args)) {
1517         sem_post(&args->m_semaphore);
1518         return NULL;
1519     }
1520 
1521     ServeOperation(args);
1522     return NULL;
1523 }
1524 
1525 bool
1526 NativeProcessLinux::Launch(LaunchArgs *args)
1527 {
1528     assert (args && "null args");
1529     if (!args)
1530         return false;
1531 
1532     NativeProcessLinux *monitor = args->m_monitor;
1533     assert (monitor && "monitor is NULL");
1534     if (!monitor)
1535         return false;
1536 
1537     const char **argv = args->m_argv;
1538     const char **envp = args->m_envp;
1539     const char *stdin_path = args->m_stdin_path;
1540     const char *stdout_path = args->m_stdout_path;
1541     const char *stderr_path = args->m_stderr_path;
1542     const char *working_dir = args->m_working_dir;
1543 
1544     lldb_utility::PseudoTerminal terminal;
1545     const size_t err_len = 1024;
1546     char err_str[err_len];
1547     lldb::pid_t pid;
1548     NativeThreadProtocolSP thread_sp;
1549 
1550     lldb::ThreadSP inferior;
1551     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1552 
1553     // Propagate the environment if one is not supplied.
1554     if (envp == NULL || envp[0] == NULL)
1555         envp = const_cast<const char **>(environ);
1556 
1557     if ((pid = terminal.Fork(err_str, err_len)) == static_cast<lldb::pid_t> (-1))
1558     {
1559         args->m_error.SetErrorToGenericError();
1560         args->m_error.SetErrorString("Process fork failed.");
1561         goto FINISH;
1562     }
1563 
1564     // Recognized child exit status codes.
1565     enum {
1566         ePtraceFailed = 1,
1567         eDupStdinFailed,
1568         eDupStdoutFailed,
1569         eDupStderrFailed,
1570         eChdirFailed,
1571         eExecFailed,
1572         eSetGidFailed
1573     };
1574 
1575     // Child process.
1576     if (pid == 0)
1577     {
1578         if (log)
1579             log->Printf ("NativeProcessLinux::%s inferior process preparing to fork", __FUNCTION__);
1580 
1581         // Trace this process.
1582         if (log)
1583             log->Printf ("NativeProcessLinux::%s inferior process issuing PTRACE_TRACEME", __FUNCTION__);
1584 
1585         if (PTRACE(PTRACE_TRACEME, 0, NULL, NULL, 0) < 0)
1586         {
1587             if (log)
1588                 log->Printf ("NativeProcessLinux::%s inferior process PTRACE_TRACEME failed", __FUNCTION__);
1589             exit(ePtraceFailed);
1590         }
1591 
1592         // Do not inherit setgid powers.
1593         if (log)
1594             log->Printf ("NativeProcessLinux::%s inferior process resetting gid", __FUNCTION__);
1595 
1596         if (setgid(getgid()) != 0)
1597         {
1598             if (log)
1599                 log->Printf ("NativeProcessLinux::%s inferior process setgid() failed", __FUNCTION__);
1600             exit(eSetGidFailed);
1601         }
1602 
1603         // Attempt to have our own process group.
1604         // TODO verify if we really want this.
1605         if (log)
1606             log->Printf ("NativeProcessLinux::%s inferior process resetting process group", __FUNCTION__);
1607 
1608         if (setpgid(0, 0) != 0)
1609         {
1610             if (log)
1611             {
1612                 const int error_code = errno;
1613                 log->Printf ("NativeProcessLinux::%s inferior setpgid() failed, errno=%d (%s), continuing with existing process group %" PRIu64,
1614                         __FUNCTION__,
1615                         error_code,
1616                         strerror (error_code),
1617                         static_cast<lldb::pid_t> (getpgid (0)));
1618             }
1619             // Don't allow this to prevent an inferior exec.
1620         }
1621 
1622         // Dup file descriptors if needed.
1623         //
1624         // FIXME: If two or more of the paths are the same we needlessly open
1625         // the same file multiple times.
1626         if (stdin_path != NULL && stdin_path[0])
1627             if (!DupDescriptor(stdin_path, STDIN_FILENO, O_RDONLY))
1628                 exit(eDupStdinFailed);
1629 
1630         if (stdout_path != NULL && stdout_path[0])
1631             if (!DupDescriptor(stdout_path, STDOUT_FILENO, O_WRONLY | O_CREAT))
1632                 exit(eDupStdoutFailed);
1633 
1634         if (stderr_path != NULL && stderr_path[0])
1635             if (!DupDescriptor(stderr_path, STDERR_FILENO, O_WRONLY | O_CREAT))
1636                 exit(eDupStderrFailed);
1637 
1638         // Change working directory
1639         if (working_dir != NULL && working_dir[0])
1640           if (0 != ::chdir(working_dir))
1641               exit(eChdirFailed);
1642 
1643         // Disable ASLR if requested.
1644         if (args->m_launch_info.GetFlags ().Test (lldb::eLaunchFlagDisableASLR))
1645         {
1646             const int old_personality = personality (LLDB_PERSONALITY_GET_CURRENT_SETTINGS);
1647             if (old_personality == -1)
1648             {
1649                 if (log)
1650                     log->Printf ("NativeProcessLinux::%s retrieval of Linux personality () failed: %s. Cannot disable ASLR.", __FUNCTION__, strerror (errno));
1651             }
1652             else
1653             {
1654                 const int new_personality = personality (ADDR_NO_RANDOMIZE | old_personality);
1655                 if (new_personality == -1)
1656                 {
1657                     if (log)
1658                         log->Printf ("NativeProcessLinux::%s setting of Linux personality () to disable ASLR failed, ignoring: %s", __FUNCTION__, strerror (errno));
1659 
1660                 }
1661                 else
1662                 {
1663                     if (log)
1664                         log->Printf ("NativeProcessLinux::%s disabling ASLR: SUCCESS", __FUNCTION__);
1665 
1666                 }
1667             }
1668         }
1669 
1670         // Execute.  We should never return.
1671         execve(argv[0],
1672                const_cast<char *const *>(argv),
1673                const_cast<char *const *>(envp));
1674         exit(eExecFailed);
1675     }
1676 
1677     // Wait for the child process to trap on its call to execve.
1678     ::pid_t wpid;
1679     int status;
1680     if ((wpid = waitpid(pid, &status, 0)) < 0)
1681     {
1682         args->m_error.SetErrorToErrno();
1683 
1684         if (log)
1685             log->Printf ("NativeProcessLinux::%s waitpid for inferior failed with %s", __FUNCTION__, args->m_error.AsCString ());
1686 
1687         // Mark the inferior as invalid.
1688         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1689         monitor->SetState (StateType::eStateInvalid);
1690 
1691         goto FINISH;
1692     }
1693     else if (WIFEXITED(status))
1694     {
1695         // open, dup or execve likely failed for some reason.
1696         args->m_error.SetErrorToGenericError();
1697         switch (WEXITSTATUS(status))
1698         {
1699             case ePtraceFailed:
1700                 args->m_error.SetErrorString("Child ptrace failed.");
1701                 break;
1702             case eDupStdinFailed:
1703                 args->m_error.SetErrorString("Child open stdin failed.");
1704                 break;
1705             case eDupStdoutFailed:
1706                 args->m_error.SetErrorString("Child open stdout failed.");
1707                 break;
1708             case eDupStderrFailed:
1709                 args->m_error.SetErrorString("Child open stderr failed.");
1710                 break;
1711             case eChdirFailed:
1712                 args->m_error.SetErrorString("Child failed to set working directory.");
1713                 break;
1714             case eExecFailed:
1715                 args->m_error.SetErrorString("Child exec failed.");
1716                 break;
1717             case eSetGidFailed:
1718                 args->m_error.SetErrorString("Child setgid failed.");
1719                 break;
1720             default:
1721                 args->m_error.SetErrorString("Child returned unknown exit status.");
1722                 break;
1723         }
1724 
1725         if (log)
1726         {
1727             log->Printf ("NativeProcessLinux::%s inferior exited with status %d before issuing a STOP",
1728                     __FUNCTION__,
1729                     WEXITSTATUS(status));
1730         }
1731 
1732         // Mark the inferior as invalid.
1733         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1734         monitor->SetState (StateType::eStateInvalid);
1735 
1736         goto FINISH;
1737     }
1738     assert(WIFSTOPPED(status) && (wpid == static_cast< ::pid_t> (pid)) &&
1739            "Could not sync with inferior process.");
1740 
1741     if (log)
1742         log->Printf ("NativeProcessLinux::%s inferior started, now in stopped state", __FUNCTION__);
1743 
1744     if (!SetDefaultPtraceOpts(pid))
1745     {
1746         args->m_error.SetErrorToErrno();
1747         if (log)
1748             log->Printf ("NativeProcessLinux::%s inferior failed to set default ptrace options: %s",
1749                     __FUNCTION__,
1750                     args->m_error.AsCString ());
1751 
1752         // Mark the inferior as invalid.
1753         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1754         monitor->SetState (StateType::eStateInvalid);
1755 
1756         goto FINISH;
1757     }
1758 
1759     // Release the master terminal descriptor and pass it off to the
1760     // NativeProcessLinux instance.  Similarly stash the inferior pid.
1761     monitor->m_terminal_fd = terminal.ReleaseMasterFileDescriptor();
1762     monitor->m_pid = pid;
1763 
1764     // Set the terminal fd to be in non blocking mode (it simplifies the
1765     // implementation of ProcessLinux::GetSTDOUT to have a non-blocking
1766     // descriptor to read from).
1767     if (!EnsureFDFlags(monitor->m_terminal_fd, O_NONBLOCK, args->m_error))
1768     {
1769         if (log)
1770             log->Printf ("NativeProcessLinux::%s inferior EnsureFDFlags failed for ensuring terminal O_NONBLOCK setting: %s",
1771                     __FUNCTION__,
1772                     args->m_error.AsCString ());
1773 
1774         // Mark the inferior as invalid.
1775         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1776         monitor->SetState (StateType::eStateInvalid);
1777 
1778         goto FINISH;
1779     }
1780 
1781     if (log)
1782         log->Printf ("NativeProcessLinux::%s() adding pid = %" PRIu64, __FUNCTION__, pid);
1783 
1784     thread_sp = monitor->AddThread (static_cast<lldb::tid_t> (pid));
1785     assert (thread_sp && "AddThread() returned a nullptr thread");
1786     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1787     monitor->SetCurrentThreadID (thread_sp->GetID ());
1788 
1789     // Let our process instance know the thread has stopped.
1790     monitor->SetState (StateType::eStateStopped);
1791 
1792 FINISH:
1793     if (log)
1794     {
1795         if (args->m_error.Success ())
1796         {
1797             log->Printf ("NativeProcessLinux::%s inferior launching succeeded", __FUNCTION__);
1798         }
1799         else
1800         {
1801             log->Printf ("NativeProcessLinux::%s inferior launching failed: %s",
1802                 __FUNCTION__,
1803                 args->m_error.AsCString ());
1804         }
1805     }
1806     return args->m_error.Success();
1807 }
1808 
1809 void
1810 NativeProcessLinux::StartAttachOpThread(AttachArgs *args, lldb_private::Error &error)
1811 {
1812     static const char *g_thread_name = "lldb.process.linux.operation";
1813 
1814     if (m_operation_thread.IsJoinable())
1815         return;
1816 
1817     m_operation_thread = ThreadLauncher::LaunchThread(g_thread_name, AttachOpThread, args, &error);
1818 }
1819 
1820 void *
1821 NativeProcessLinux::AttachOpThread(void *arg)
1822 {
1823     AttachArgs *args = static_cast<AttachArgs*>(arg);
1824 
1825     if (!Attach(args)) {
1826         sem_post(&args->m_semaphore);
1827         return NULL;
1828     }
1829 
1830     ServeOperation(args);
1831     return NULL;
1832 }
1833 
1834 bool
1835 NativeProcessLinux::Attach(AttachArgs *args)
1836 {
1837     lldb::pid_t pid = args->m_pid;
1838 
1839     NativeProcessLinux *monitor = args->m_monitor;
1840     lldb::ThreadSP inferior;
1841     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1842 
1843     // Use a map to keep track of the threads which we have attached/need to attach.
1844     Host::TidMap tids_to_attach;
1845     if (pid <= 1)
1846     {
1847         args->m_error.SetErrorToGenericError();
1848         args->m_error.SetErrorString("Attaching to process 1 is not allowed.");
1849         goto FINISH;
1850     }
1851 
1852     while (Host::FindProcessThreads(pid, tids_to_attach))
1853     {
1854         for (Host::TidMap::iterator it = tids_to_attach.begin();
1855              it != tids_to_attach.end();)
1856         {
1857             if (it->second == false)
1858             {
1859                 lldb::tid_t tid = it->first;
1860 
1861                 // Attach to the requested process.
1862                 // An attach will cause the thread to stop with a SIGSTOP.
1863                 if (PTRACE(PTRACE_ATTACH, tid, NULL, NULL, 0) < 0)
1864                 {
1865                     // No such thread. The thread may have exited.
1866                     // More error handling may be needed.
1867                     if (errno == ESRCH)
1868                     {
1869                         it = tids_to_attach.erase(it);
1870                         continue;
1871                     }
1872                     else
1873                     {
1874                         args->m_error.SetErrorToErrno();
1875                         goto FINISH;
1876                     }
1877                 }
1878 
1879                 int status;
1880                 // Need to use __WALL otherwise we receive an error with errno=ECHLD
1881                 // At this point we should have a thread stopped if waitpid succeeds.
1882                 if ((status = waitpid(tid, NULL, __WALL)) < 0)
1883                 {
1884                     // No such thread. The thread may have exited.
1885                     // More error handling may be needed.
1886                     if (errno == ESRCH)
1887                     {
1888                         it = tids_to_attach.erase(it);
1889                         continue;
1890                     }
1891                     else
1892                     {
1893                         args->m_error.SetErrorToErrno();
1894                         goto FINISH;
1895                     }
1896                 }
1897 
1898                 if (!SetDefaultPtraceOpts(tid))
1899                 {
1900                     args->m_error.SetErrorToErrno();
1901                     goto FINISH;
1902                 }
1903 
1904 
1905                 if (log)
1906                     log->Printf ("NativeProcessLinux::%s() adding tid = %" PRIu64, __FUNCTION__, tid);
1907 
1908                 it->second = true;
1909 
1910                 // Create the thread, mark it as stopped.
1911                 NativeThreadProtocolSP thread_sp (monitor->AddThread (static_cast<lldb::tid_t> (tid)));
1912                 assert (thread_sp && "AddThread() returned a nullptr");
1913                 reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1914                 monitor->SetCurrentThreadID (thread_sp->GetID ());
1915             }
1916 
1917             // move the loop forward
1918             ++it;
1919         }
1920     }
1921 
1922     if (tids_to_attach.size() > 0)
1923     {
1924         monitor->m_pid = pid;
1925         // Let our process instance know the thread has stopped.
1926         monitor->SetState (StateType::eStateStopped);
1927     }
1928     else
1929     {
1930         args->m_error.SetErrorToGenericError();
1931         args->m_error.SetErrorString("No such process.");
1932     }
1933 
1934  FINISH:
1935     return args->m_error.Success();
1936 }
1937 
1938 bool
1939 NativeProcessLinux::SetDefaultPtraceOpts(lldb::pid_t pid)
1940 {
1941     long ptrace_opts = 0;
1942 
1943     // Have the child raise an event on exit.  This is used to keep the child in
1944     // limbo until it is destroyed.
1945     ptrace_opts |= PTRACE_O_TRACEEXIT;
1946 
1947     // Have the tracer trace threads which spawn in the inferior process.
1948     // TODO: if we want to support tracing the inferiors' child, add the
1949     // appropriate ptrace flags here (PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)
1950     ptrace_opts |= PTRACE_O_TRACECLONE;
1951 
1952     // Have the tracer notify us before execve returns
1953     // (needed to disable legacy SIGTRAP generation)
1954     ptrace_opts |= PTRACE_O_TRACEEXEC;
1955 
1956     return PTRACE(PTRACE_SETOPTIONS, pid, NULL, (void*)ptrace_opts, 0) >= 0;
1957 }
1958 
1959 static ExitType convert_pid_status_to_exit_type (int status)
1960 {
1961     if (WIFEXITED (status))
1962         return ExitType::eExitTypeExit;
1963     else if (WIFSIGNALED (status))
1964         return ExitType::eExitTypeSignal;
1965     else if (WIFSTOPPED (status))
1966         return ExitType::eExitTypeStop;
1967     else
1968     {
1969         // We don't know what this is.
1970         return ExitType::eExitTypeInvalid;
1971     }
1972 }
1973 
1974 static int convert_pid_status_to_return_code (int status)
1975 {
1976     if (WIFEXITED (status))
1977         return WEXITSTATUS (status);
1978     else if (WIFSIGNALED (status))
1979         return WTERMSIG (status);
1980     else if (WIFSTOPPED (status))
1981         return WSTOPSIG (status);
1982     else
1983     {
1984         // We don't know what this is.
1985         return ExitType::eExitTypeInvalid;
1986     }
1987 }
1988 
1989 // Main process monitoring waitpid-loop handler.
1990 bool
1991 NativeProcessLinux::MonitorCallback(void *callback_baton,
1992                                 lldb::pid_t pid,
1993                                 bool exited,
1994                                 int signal,
1995                                 int status)
1996 {
1997     Log *log (GetLogIfAnyCategoriesSet (LIBLLDB_LOG_PROCESS));
1998 
1999     NativeProcessLinux *const process = static_cast<NativeProcessLinux*>(callback_baton);
2000     assert (process && "process is null");
2001     if (!process)
2002     {
2003         if (log)
2004             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " callback_baton was null, can't determine process to use", __FUNCTION__, pid);
2005         return true;
2006     }
2007 
2008     // Certain activities differ based on whether the pid is the tid of the main thread.
2009     const bool is_main_thread = (pid == process->GetID ());
2010 
2011     // Assume we keep monitoring by default.
2012     bool stop_monitoring = false;
2013 
2014     // Handle when the thread exits.
2015     if (exited)
2016     {
2017         if (log)
2018             log->Printf ("NativeProcessLinux::%s() got exit signal, tid = %"  PRIu64 " (%s main thread)", __FUNCTION__, pid, is_main_thread ? "is" : "is not");
2019 
2020         // This is a thread that exited.  Ensure we're not tracking it anymore.
2021         const bool thread_found = process->StopTrackingThread (pid);
2022 
2023         if (is_main_thread)
2024         {
2025             // We only set the exit status and notify the delegate if we haven't already set the process
2026             // state to an exited state.  We normally should have received a SIGTRAP | (PTRACE_EVENT_EXIT << 8)
2027             // for the main thread.
2028             const bool already_notified = (process->GetState() == StateType::eStateExited) | (process->GetState () == StateType::eStateCrashed);
2029             if (!already_notified)
2030             {
2031                 if (log)
2032                     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 ()));
2033                 // The main thread exited.  We're done monitoring.  Report to delegate.
2034                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
2035 
2036                 // Notify delegate that our process has exited.
2037                 process->SetState (StateType::eStateExited, true);
2038             }
2039             else
2040             {
2041                 if (log)
2042                     log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " main thread now exited (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
2043             }
2044             return true;
2045         }
2046         else
2047         {
2048             // Do we want to report to the delegate in this case?  I think not.  If this was an orderly
2049             // thread exit, we would already have received the SIGTRAP | (PTRACE_EVENT_EXIT << 8) signal,
2050             // and we would have done an all-stop then.
2051             if (log)
2052                 log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " handling non-main thread exit (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
2053 
2054             // Not the main thread, we keep going.
2055             return false;
2056         }
2057     }
2058 
2059     // Get details on the signal raised.
2060     siginfo_t info;
2061     int ptrace_err = 0;
2062 
2063     if (!process->GetSignalInfo (pid, &info, ptrace_err))
2064     {
2065         if (ptrace_err == EINVAL)
2066         {
2067             process->OnGroupStop (pid);
2068         }
2069         else
2070         {
2071             // ptrace(GETSIGINFO) failed (but not due to group-stop).
2072 
2073             // A return value of ESRCH means the thread/process is no longer on the system,
2074             // so it was killed somehow outside of our control.  Either way, we can't do anything
2075             // with it anymore.
2076 
2077             // We stop monitoring if it was the main thread.
2078             stop_monitoring = is_main_thread;
2079 
2080             // Stop tracking the metadata for the thread since it's entirely off the system now.
2081             const bool thread_found = process->StopTrackingThread (pid);
2082 
2083             if (log)
2084                 log->Printf ("NativeProcessLinux::%s GetSignalInfo failed: %s, tid = %" PRIu64 ", signal = %d, status = %d (%s, %s, %s)",
2085                              __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");
2086 
2087             if (is_main_thread)
2088             {
2089                 // Notify the delegate - our process is not available but appears to have been killed outside
2090                 // our control.  Is eStateExited the right exit state in this case?
2091                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
2092                 process->SetState (StateType::eStateExited, true);
2093             }
2094             else
2095             {
2096                 // This thread was pulled out from underneath us.  Anything to do here? Do we want to do an all stop?
2097                 if (log)
2098                     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);
2099             }
2100         }
2101     }
2102     else
2103     {
2104         // We have retrieved the signal info.  Dispatch appropriately.
2105         if (info.si_signo == SIGTRAP)
2106             process->MonitorSIGTRAP(&info, pid);
2107         else
2108             process->MonitorSignal(&info, pid, exited);
2109 
2110         stop_monitoring = false;
2111     }
2112 
2113     return stop_monitoring;
2114 }
2115 
2116 void
2117 NativeProcessLinux::MonitorSIGTRAP(const siginfo_t *info, lldb::pid_t pid)
2118 {
2119     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2120     const bool is_main_thread = (pid == GetID ());
2121 
2122     assert(info && info->si_signo == SIGTRAP && "Unexpected child signal!");
2123     if (!info)
2124         return;
2125 
2126     // See if we can find a thread for this signal.
2127     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2128     if (!thread_sp)
2129     {
2130         if (log)
2131             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2132     }
2133 
2134     switch (info->si_code)
2135     {
2136     // TODO: these two cases are required if we want to support tracing of the inferiors' children.  We'd need this to debug a monitor.
2137     // case (SIGTRAP | (PTRACE_EVENT_FORK << 8)):
2138     // case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):
2139 
2140     case (SIGTRAP | (PTRACE_EVENT_CLONE << 8)):
2141     {
2142         lldb::tid_t tid = LLDB_INVALID_THREAD_ID;
2143 
2144         unsigned long event_message = 0;
2145         if (GetEventMessage(pid, &event_message))
2146             tid = static_cast<lldb::tid_t> (event_message);
2147 
2148         if (log)
2149             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " received thread creation event for tid %" PRIu64, __FUNCTION__, pid, tid);
2150 
2151         // If we don't track the thread yet: create it, mark as stopped.
2152         // If we do track it, this is the wait we needed.  Now resume the new thread.
2153         // In all cases, resume the current (i.e. main process) thread.
2154         bool created_now = false;
2155         thread_sp = GetOrCreateThread (tid, created_now);
2156         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2157 
2158         // If the thread was already tracked, it means the created thread already received its SI_USER notification of creation.
2159         if (!created_now)
2160         {
2161             // FIXME loops like we want to stop all theads here.
2162             // StopAllThreads
2163 
2164             // We can now resume the newly created thread since it is fully created.
2165             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2166             Resume (tid, LLDB_INVALID_SIGNAL_NUMBER);
2167         }
2168         else
2169         {
2170             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2171             // this thread is ready to go.
2172             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2173         }
2174 
2175         // In all cases, we can resume the main thread here.
2176         Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
2177         break;
2178     }
2179 
2180     case (SIGTRAP | (PTRACE_EVENT_EXEC << 8)):
2181     {
2182         NativeThreadProtocolSP main_thread_sp;
2183 
2184         if (log)
2185             log->Printf ("NativeProcessLinux::%s() received exec event, code = %d", __FUNCTION__, info->si_code ^ SIGTRAP);
2186 
2187         // Remove all but the main thread here.
2188         // FIXME check if we really need to do this - how does ptrace behave under exec when multiple threads were present
2189         // before the exec?  If we get all the detach signals right, we don't need to do this.  However, it makes it clearer
2190         // what we should really be tracking.
2191         {
2192             Mutex::Locker locker (m_threads_mutex);
2193 
2194             if (log)
2195                 log->Printf ("NativeProcessLinux::%s exec received, stop tracking all but main thread", __FUNCTION__);
2196 
2197             for (auto thread_sp : m_threads)
2198             {
2199                 const bool is_main_thread = thread_sp && thread_sp->GetID () == GetID ();
2200                 if (is_main_thread)
2201                 {
2202                     main_thread_sp = thread_sp;
2203                     if (log)
2204                         log->Printf ("NativeProcessLinux::%s found main thread with tid %" PRIu64 ", keeping", __FUNCTION__, main_thread_sp->GetID ());
2205                 }
2206                 else
2207                 {
2208                     if (log)
2209                         log->Printf ("NativeProcessLinux::%s discarding non-main-thread tid %" PRIu64 " due to exec", __FUNCTION__, thread_sp->GetID ());
2210                 }
2211             }
2212 
2213             m_threads.clear ();
2214 
2215             if (main_thread_sp)
2216             {
2217                 m_threads.push_back (main_thread_sp);
2218                 SetCurrentThreadID (main_thread_sp->GetID ());
2219                 reinterpret_cast<NativeThreadLinux*>(main_thread_sp.get())->SetStoppedByExec ();
2220             }
2221             else
2222             {
2223                 SetCurrentThreadID (LLDB_INVALID_THREAD_ID);
2224                 if (log)
2225                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 "no main thread found, discarded all threads, we're in a no-thread state!", __FUNCTION__, GetID ());
2226             }
2227         }
2228 
2229         // Let our delegate know we have just exec'd.
2230         NotifyDidExec ();
2231 
2232         // If we have a main thread, indicate we are stopped.
2233         assert (main_thread_sp && "exec called during ptraced process but no main thread metadata tracked");
2234         SetState (StateType::eStateStopped);
2235 
2236         break;
2237     }
2238 
2239     case (SIGTRAP | (PTRACE_EVENT_EXIT << 8)):
2240     {
2241         // The inferior process or one of its threads is about to exit.
2242         // Maintain the process or thread in a state of "limbo" until we are
2243         // explicitly commanded to detach, destroy, resume, etc.
2244         unsigned long data = 0;
2245         if (!GetEventMessage(pid, &data))
2246             data = -1;
2247 
2248         if (log)
2249         {
2250             log->Printf ("NativeProcessLinux::%s() received PTRACE_EVENT_EXIT, data = %lx (WIFEXITED=%s,WIFSIGNALED=%s), pid = %" PRIu64 " (%s)",
2251                          __FUNCTION__,
2252                          data, WIFEXITED (data) ? "true" : "false", WIFSIGNALED (data) ? "true" : "false",
2253                          pid,
2254                     is_main_thread ? "is main thread" : "not main thread");
2255         }
2256 
2257         // Set the thread to exited.
2258         if (thread_sp)
2259             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetExited ();
2260         else
2261         {
2262             if (log)
2263                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " failed to retrieve thread for tid %" PRIu64", cannot set thread state", __FUNCTION__, GetID (), pid);
2264         }
2265 
2266         if (is_main_thread)
2267         {
2268             SetExitStatus (convert_pid_status_to_exit_type (data), convert_pid_status_to_return_code (data), nullptr, true);
2269             // Resume the thread so it completely exits.
2270             Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
2271         }
2272         else
2273         {
2274             // FIXME figure out the path where we plan to reap the metadata for the thread.
2275         }
2276 
2277         break;
2278     }
2279 
2280     case 0:
2281     case TRAP_TRACE:
2282         // We receive this on single stepping.
2283         if (log)
2284             log->Printf ("NativeProcessLinux::%s() received trace event, pid = %" PRIu64 " (single stepping)", __FUNCTION__, pid);
2285 
2286         if (thread_sp)
2287         {
2288             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2289             SetCurrentThreadID (thread_sp->GetID ());
2290         }
2291         else
2292         {
2293             if (log)
2294                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 " single stepping received trace but thread not found", __FUNCTION__, GetID (), pid);
2295         }
2296 
2297         // Tell the process we have a stop (from single stepping).
2298         SetState (StateType::eStateStopped, true);
2299         break;
2300 
2301     case SI_KERNEL:
2302     case TRAP_BRKPT:
2303         if (log)
2304             log->Printf ("NativeProcessLinux::%s() received breakpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2305 
2306         // Mark the thread as stopped at breakpoint.
2307         if (thread_sp)
2308         {
2309             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2310             Error error = FixupBreakpointPCAsNeeded (thread_sp);
2311             if (error.Fail ())
2312             {
2313                 if (log)
2314                     log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " fixup: %s", __FUNCTION__, pid, error.AsCString ());
2315             }
2316         }
2317         else
2318         {
2319             if (log)
2320                 log->Printf ("NativeProcessLinux::%s()  pid = %" PRIu64 ": warning, cannot process software breakpoint since no thread metadata", __FUNCTION__, pid);
2321         }
2322 
2323 
2324         // Tell the process we have a stop from this thread.
2325         SetCurrentThreadID (pid);
2326         SetState (StateType::eStateStopped, true);
2327         break;
2328 
2329     case TRAP_HWBKPT:
2330         if (log)
2331             log->Printf ("NativeProcessLinux::%s() received watchpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2332 
2333         // Mark the thread as stopped at watchpoint.
2334         // The address is at (lldb::addr_t)info->si_addr if we need it.
2335         if (thread_sp)
2336             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2337         else
2338         {
2339             if (log)
2340                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ": warning, cannot process hardware breakpoint since no thread metadata", __FUNCTION__, GetID (), pid);
2341         }
2342 
2343         // Tell the process we have a stop from this thread.
2344         SetCurrentThreadID (pid);
2345         SetState (StateType::eStateStopped, true);
2346         break;
2347 
2348     case SIGTRAP:
2349     case (SIGTRAP | 0x80):
2350         if (log)
2351             log->Printf ("NativeProcessLinux::%s() received system call stop event, pid %" PRIu64 "tid %" PRIu64, __FUNCTION__, GetID (), pid);
2352         // Ignore these signals until we know more about them.
2353         Resume(pid, 0);
2354         break;
2355 
2356     default:
2357         assert(false && "Unexpected SIGTRAP code!");
2358         if (log)
2359             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)));
2360         break;
2361 
2362     }
2363 }
2364 
2365 void
2366 NativeProcessLinux::MonitorSignal(const siginfo_t *info, lldb::pid_t pid, bool exited)
2367 {
2368     assert (info && "null info");
2369     if (!info)
2370         return;
2371 
2372     const int signo = info->si_signo;
2373     const bool is_from_llgs = info->si_pid == getpid ();
2374 
2375     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2376 
2377     // POSIX says that process behaviour is undefined after it ignores a SIGFPE,
2378     // SIGILL, SIGSEGV, or SIGBUS *unless* that signal was generated by a
2379     // kill(2) or raise(3).  Similarly for tgkill(2) on Linux.
2380     //
2381     // IOW, user generated signals never generate what we consider to be a
2382     // "crash".
2383     //
2384     // Similarly, ACK signals generated by this monitor.
2385 
2386     // See if we can find a thread for this signal.
2387     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2388     if (!thread_sp)
2389     {
2390         if (log)
2391             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2392     }
2393 
2394     // Handle the signal.
2395     if (info->si_code == SI_TKILL || info->si_code == SI_USER)
2396     {
2397         if (log)
2398             log->Printf ("NativeProcessLinux::%s() received signal %s (%d) with code %s, (siginfo pid = %d (%s), waitpid pid = %" PRIu64 ")",
2399                             __FUNCTION__,
2400                             GetUnixSignals ().GetSignalAsCString (signo),
2401                             signo,
2402                             (info->si_code == SI_TKILL ? "SI_TKILL" : "SI_USER"),
2403                             info->si_pid,
2404                             is_from_llgs ? "from llgs" : "not from llgs",
2405                             pid);
2406     }
2407 
2408     // Check for new thread notification.
2409     if ((info->si_pid == 0) && (info->si_code == SI_USER))
2410     {
2411         // A new thread creation is being signaled.  This is one of two parts that come in
2412         // a non-deterministic order.  pid is the thread id.
2413         if (log)
2414             log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": new thread notification",
2415                      __FUNCTION__, GetID (), pid);
2416 
2417         // Did we already create the thread?
2418         bool created_now = false;
2419         thread_sp = GetOrCreateThread (pid, created_now);
2420         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2421 
2422         // If the thread was already tracked, it means the main thread already received its SIGTRAP for the create.
2423         if (!created_now)
2424         {
2425             // We can now resume this thread up since it is fully created.
2426             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2427             Resume (thread_sp->GetID (), LLDB_INVALID_SIGNAL_NUMBER);
2428         }
2429         else
2430         {
2431             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2432             // this thread is ready to go.
2433             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2434         }
2435 
2436         // Done handling.
2437         return;
2438     }
2439 
2440     // Check for thread stop notification.
2441     if (is_from_llgs && (info->si_code == SI_TKILL) && (signo == SIGSTOP))
2442     {
2443         // This is a tgkill()-based stop.
2444         if (thread_sp)
2445         {
2446             // An inferior thread just stopped.  Mark it as such.
2447             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2448             SetCurrentThreadID (thread_sp->GetID ());
2449 
2450             // Remove this tid from the wait-for-stop set.
2451             Mutex::Locker locker (m_wait_for_stop_tids_mutex);
2452 
2453             auto removed_count = m_wait_for_stop_tids.erase (thread_sp->GetID ());
2454             if (removed_count < 1)
2455             {
2456                 log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": tgkill()-stopped thread not in m_wait_for_stop_tids",
2457                              __FUNCTION__, GetID (), thread_sp->GetID ());
2458 
2459             }
2460 
2461             // If this is the last thread in the m_wait_for_stop_tids, we need to notify
2462             // the delegate that a stop has occurred now that every thread that was supposed
2463             // to stop has stopped.
2464             if (m_wait_for_stop_tids.empty ())
2465             {
2466                 if (log)
2467                 {
2468                     log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ", setting process state to stopped now that all tids marked for stop have completed",
2469                                  __FUNCTION__,
2470                                  GetID (),
2471                                  pid);
2472                 }
2473                 SetState (StateType::eStateStopped, true);
2474             }
2475         }
2476 
2477         // Done handling.
2478         return;
2479     }
2480 
2481     if (log)
2482         log->Printf ("NativeProcessLinux::%s() received signal %s", __FUNCTION__, GetUnixSignals ().GetSignalAsCString (signo));
2483 
2484     switch (signo)
2485     {
2486     case SIGSEGV:
2487         {
2488             lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2489 
2490             // FIXME figure out how to propagate this properly.  Seems like it
2491             // should go in ThreadStopInfo.
2492             // We can get more details on the exact nature of the crash here.
2493             // ProcessMessage::CrashReason reason = GetCrashReasonForSIGSEGV(info);
2494             if (!exited)
2495             {
2496                 // This is just a pre-signal-delivery notification of the incoming signal.
2497                 // Send a stop to the debugger.
2498                 if (thread_sp)
2499                 {
2500                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2501                     SetCurrentThreadID (thread_sp->GetID ());
2502                 }
2503                 SetState (StateType::eStateStopped, true);
2504             }
2505             else
2506             {
2507                 if (thread_sp)
2508                 {
2509                     // FIXME figure out what type this is.
2510                     const uint64_t exception_type = static_cast<uint64_t> (SIGSEGV);
2511                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetCrashedWithException (exception_type, fault_addr);
2512                 }
2513                 SetState (StateType::eStateCrashed, true);
2514             }
2515         }
2516         break;
2517 
2518     case SIGABRT:
2519     case SIGILL:
2520     case SIGFPE:
2521     case SIGBUS:
2522         {
2523             // Break these out into separate cases once I have more data for each type of signal.
2524             lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2525             if (!exited)
2526             {
2527                 // This is just a pre-signal-delivery notification of the incoming signal.
2528                 // Send a stop to the debugger.
2529                 if (thread_sp)
2530                 {
2531                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2532                     SetCurrentThreadID (thread_sp->GetID ());
2533                 }
2534                 SetState (StateType::eStateStopped, true);
2535             }
2536             else
2537             {
2538                 if (thread_sp)
2539                 {
2540                     // FIXME figure out how to report exit by signal correctly.
2541                     const uint64_t exception_type = static_cast<uint64_t> (SIGABRT);
2542                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetCrashedWithException (exception_type, fault_addr);
2543                 }
2544                 SetState (StateType::eStateCrashed, true);
2545             }
2546         }
2547         break;
2548 
2549     case SIGSTOP:
2550         {
2551             if (log)
2552             {
2553                 if (is_from_llgs)
2554                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " received SIGSTOP from llgs, most likely an interrupt", __FUNCTION__, GetID (), pid);
2555                 else
2556                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " received SIGSTOP from outside of debugger", __FUNCTION__, GetID (), pid);
2557             }
2558 
2559             // Save group stop tids to wait for.
2560             SetGroupStopTids (pid, SIGSTOP);
2561             // Fall through to deliver signal to thread.
2562             // This will trigger a group stop sequence, after which we'll notify the process that everything stopped.
2563         }
2564 
2565     default:
2566         {
2567             if (log)
2568                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " resuming thread with signal %s (%d)", __FUNCTION__, GetID (), pid, GetUnixSignals().GetSignalAsCString (signo), signo);
2569 
2570             // Pass the signal on to the inferior.
2571             const bool resume_success = Resume (pid, signo);
2572 
2573             if (log)
2574                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " resume %s", __FUNCTION__, GetID (), pid, resume_success ? "SUCCESS" : "FAILURE");
2575 
2576         }
2577         break;
2578     }
2579 }
2580 
2581 void
2582 NativeProcessLinux::SetGroupStopTids (lldb::tid_t signaled_thread_tid, int signo)
2583 {
2584     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
2585 
2586     // Lock 1 - thread lock.
2587     {
2588         Mutex::Locker locker (m_threads_mutex);
2589         // Lock 2 - group stop tids
2590         {
2591             Mutex::Locker locker (m_wait_for_group_stop_tids_mutex);
2592             if (log)
2593                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " loading up known threads in set%s",
2594                              __FUNCTION__,
2595                              GetID (),
2596                              signaled_thread_tid,
2597                              m_wait_for_group_stop_tids.empty () ? " (currently empty)"
2598                                 : "(group_stop_tids not empty?!?)");
2599 
2600             // Add all known threads not already stopped into the wait for group-stop tids.
2601             for (auto thread_sp : m_threads)
2602             {
2603                 int unused_signo = LLDB_INVALID_SIGNAL_NUMBER;
2604                 if (thread_sp && !((NativeThreadLinux*)thread_sp.get())->IsStopped (&unused_signo))
2605                 {
2606                     // Wait on this thread for a group stop before we notify the delegate about the process state change.
2607                     m_wait_for_group_stop_tids.insert (thread_sp->GetID ());
2608                 }
2609             }
2610 
2611             m_group_stop_signal_tid = signaled_thread_tid;
2612             m_group_stop_signal = signo;
2613         }
2614     }
2615 }
2616 
2617 void
2618 NativeProcessLinux::OnGroupStop (lldb::tid_t tid)
2619 {
2620     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
2621     bool should_tell_delegate = false;
2622 
2623     // Lock 1 - thread lock.
2624     {
2625         Mutex::Locker locker (m_threads_mutex);
2626         // Lock 2 - group stop tids
2627         {
2628             Mutex::Locker locker (m_wait_for_group_stop_tids_mutex);
2629 
2630             // Remove this thread from the set.
2631             auto remove_result = m_wait_for_group_stop_tids.erase (tid);
2632             if (log)
2633                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " tried to remove tid from group-stop set: %s",
2634                              __FUNCTION__,
2635                              GetID (),
2636                              tid,
2637                              remove_result > 0 ? "SUCCESS" : "FAILURE");
2638 
2639             // Grab the thread metadata for this thread.
2640             NativeThreadProtocolSP thread_sp = GetThreadByIDUnlocked (tid);
2641             if (thread_sp)
2642             {
2643                 NativeThreadLinux *const linux_thread = static_cast<NativeThreadLinux*> (thread_sp.get ());
2644                 if (thread_sp->GetID () == m_group_stop_signal_tid)
2645                 {
2646                     linux_thread->SetStoppedBySignal (m_group_stop_signal);
2647                     if (log)
2648                         log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " set group stop tid to state 'stopped by signal %d'",
2649                                      __FUNCTION__,
2650                                      GetID (),
2651                                      tid,
2652                                      m_group_stop_signal);
2653                 }
2654                 else
2655                 {
2656                     int stopping_signal = LLDB_INVALID_SIGNAL_NUMBER;
2657                     if (linux_thread->IsStopped (&stopping_signal))
2658                     {
2659                         if (log)
2660                             log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " thread is already stopped with signal %d, not clearing",
2661                                          __FUNCTION__,
2662                                          GetID (),
2663                                          tid,
2664                                          stopping_signal);
2665 
2666                     }
2667                     else
2668                     {
2669                         linux_thread->SetStoppedBySignal (0);
2670                         if (log)
2671                             log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " set stopped by signal with signal 0 (i.e. debugger-initiated stop)",
2672                                          __FUNCTION__,
2673                                          GetID (),
2674                                          tid);
2675 
2676                     }
2677                 }
2678             }
2679             else
2680             {
2681                 if (log)
2682                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " WARNING failed to find thread metadata for tid",
2683                                  __FUNCTION__,
2684                                  GetID (),
2685                                  tid);
2686 
2687             }
2688 
2689             // If there are no more threads we're waiting on for group stop, signal the process.
2690             if (m_wait_for_group_stop_tids.empty ())
2691             {
2692                 if (log)
2693                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " done waiting for group stop, will notify delegate of process state change",
2694                                  __FUNCTION__,
2695                                  GetID (),
2696                                  tid);
2697 
2698                 SetCurrentThreadID (m_group_stop_signal_tid);
2699 
2700                 // Tell the delegate about the stop event, after we release our mutexes.
2701                 should_tell_delegate = true;
2702             }
2703         }
2704     }
2705 
2706     // If we're ready to broadcast the process event change, do it now that we're no longer
2707     // holding any locks.  Note this does introduce a potential race, we should think about
2708     // adding a notification queue.
2709     if (should_tell_delegate)
2710     {
2711         if (log)
2712             log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " done waiting for group stop, notifying delegate of process state change",
2713                          __FUNCTION__,
2714                          GetID (),
2715                          tid);
2716         SetState (StateType::eStateStopped, true);
2717     }
2718 }
2719 
2720 Error
2721 NativeProcessLinux::Resume (const ResumeActionList &resume_actions)
2722 {
2723     Error error;
2724 
2725     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_THREAD));
2726     if (log)
2727         log->Printf ("NativeProcessLinux::%s called: pid %" PRIu64, __FUNCTION__, GetID ());
2728 
2729     int run_thread_count = 0;
2730     int stop_thread_count = 0;
2731     int step_thread_count = 0;
2732 
2733     std::vector<NativeThreadProtocolSP> new_stop_threads;
2734 
2735     Mutex::Locker locker (m_threads_mutex);
2736     for (auto thread_sp : m_threads)
2737     {
2738         assert (thread_sp && "thread list should not contain NULL threads");
2739         NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get ());
2740 
2741         const ResumeAction *const action = resume_actions.GetActionForThread (thread_sp->GetID (), true);
2742         assert (action && "NULL ResumeAction returned for thread during Resume ()");
2743 
2744         if (log)
2745         {
2746             log->Printf ("NativeProcessLinux::%s processing resume action state %s for pid %" PRIu64 " tid %" PRIu64,
2747                     __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2748         }
2749 
2750         switch (action->state)
2751         {
2752         case eStateRunning:
2753             // Run the thread, possibly feeding it the signal.
2754             linux_thread_p->SetRunning ();
2755             if (action->signal > 0)
2756             {
2757                 // Resume the thread and deliver the given signal,
2758                 // then mark as delivered.
2759                 Resume (thread_sp->GetID (), action->signal);
2760                 resume_actions.SetSignalHandledForThread (thread_sp->GetID ());
2761             }
2762             else
2763             {
2764                 // Just resume the thread with no signal.
2765                 Resume (thread_sp->GetID (), LLDB_INVALID_SIGNAL_NUMBER);
2766             }
2767             ++run_thread_count;
2768             break;
2769 
2770         case eStateStepping:
2771             // Note: if we have multiple threads, we may need to stop
2772             // the other threads first, then step this one.
2773             linux_thread_p->SetStepping ();
2774             if (SingleStep (thread_sp->GetID (), 0))
2775             {
2776                 if (log)
2777                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " single step succeeded",
2778                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2779             }
2780             else
2781             {
2782                 if (log)
2783                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " single step failed",
2784                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2785             }
2786             ++step_thread_count;
2787             break;
2788 
2789         case eStateSuspended:
2790         case eStateStopped:
2791             if (!StateIsStoppedState (linux_thread_p->GetState (), false))
2792                 new_stop_threads.push_back (thread_sp);
2793             else
2794             {
2795                 if (log)
2796                     log->Printf ("NativeProcessLinux::%s no need to stop pid %" PRIu64 " tid %" PRIu64 ", thread state already %s",
2797                                  __FUNCTION__, GetID (), thread_sp->GetID (), StateAsCString (linux_thread_p->GetState ()));
2798             }
2799 
2800             ++stop_thread_count;
2801             break;
2802 
2803         default:
2804             return Error ("NativeProcessLinux::%s (): unexpected state %s specified for pid %" PRIu64 ", tid %" PRIu64,
2805                     __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2806         }
2807     }
2808 
2809     // If any thread was set to run, notify the process state as running.
2810     if (run_thread_count > 0)
2811         SetState (StateType::eStateRunning, true);
2812 
2813     // Now do a tgkill SIGSTOP on each thread we want to stop.
2814     if (!new_stop_threads.empty ())
2815     {
2816         // Lock the m_wait_for_stop_tids set so we can fill it with every thread we expect to have stopped.
2817         Mutex::Locker stop_thread_id_locker (m_wait_for_stop_tids_mutex);
2818         for (auto thread_sp : new_stop_threads)
2819         {
2820             // Send a stop signal to the thread.
2821             const int result = tgkill (GetID (), thread_sp->GetID (), SIGSTOP);
2822             if (result != 0)
2823             {
2824                 // tgkill failed.
2825                 if (log)
2826                     log->Printf ("NativeProcessLinux::%s error: tgkill SIGSTOP for pid %" PRIu64 " tid %" PRIu64 "failed, retval %d",
2827                                  __FUNCTION__, GetID (), thread_sp->GetID (), result);
2828             }
2829             else
2830             {
2831                 // tgkill succeeded.  Don't mark the thread state, though.  Let the signal
2832                 // handling mark it.
2833                 if (log)
2834                     log->Printf ("NativeProcessLinux::%s tgkill SIGSTOP for pid %" PRIu64 " tid %" PRIu64 " succeeded",
2835                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2836 
2837                 // Add it to the set of threads we expect to signal a stop.
2838                 // We won't tell the delegate about it until this list drains to empty.
2839                 m_wait_for_stop_tids.insert (thread_sp->GetID ());
2840             }
2841         }
2842     }
2843 
2844     return error;
2845 }
2846 
2847 Error
2848 NativeProcessLinux::Halt ()
2849 {
2850     Error error;
2851 
2852     // FIXME check if we're already stopped
2853     const bool is_stopped = false;
2854     if (is_stopped)
2855         return error;
2856 
2857     if (kill (GetID (), SIGSTOP) != 0)
2858         error.SetErrorToErrno ();
2859 
2860     return error;
2861 }
2862 
2863 Error
2864 NativeProcessLinux::Detach ()
2865 {
2866     Error error;
2867 
2868     // Tell ptrace to detach from the process.
2869     if (GetID () != LLDB_INVALID_PROCESS_ID)
2870         error = Detach (GetID ());
2871 
2872     // Stop monitoring the inferior.
2873     StopMonitor ();
2874 
2875     // No error.
2876     return error;
2877 }
2878 
2879 Error
2880 NativeProcessLinux::Signal (int signo)
2881 {
2882     Error error;
2883 
2884     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2885     if (log)
2886         log->Printf ("NativeProcessLinux::%s: sending signal %d (%s) to pid %" PRIu64,
2887                 __FUNCTION__, signo,  GetUnixSignals ().GetSignalAsCString (signo), GetID ());
2888 
2889     if (kill(GetID(), signo))
2890         error.SetErrorToErrno();
2891 
2892     return error;
2893 }
2894 
2895 Error
2896 NativeProcessLinux::Kill ()
2897 {
2898     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2899     if (log)
2900         log->Printf ("NativeProcessLinux::%s called for PID %" PRIu64, __FUNCTION__, GetID ());
2901 
2902     Error error;
2903 
2904     switch (m_state)
2905     {
2906         case StateType::eStateInvalid:
2907         case StateType::eStateExited:
2908         case StateType::eStateCrashed:
2909         case StateType::eStateDetached:
2910         case StateType::eStateUnloaded:
2911             // Nothing to do - the process is already dead.
2912             if (log)
2913                 log->Printf ("NativeProcessLinux::%s ignored for PID %" PRIu64 " due to current state: %s", __FUNCTION__, GetID (), StateAsCString (m_state));
2914             return error;
2915 
2916         case StateType::eStateConnected:
2917         case StateType::eStateAttaching:
2918         case StateType::eStateLaunching:
2919         case StateType::eStateStopped:
2920         case StateType::eStateRunning:
2921         case StateType::eStateStepping:
2922         case StateType::eStateSuspended:
2923             // We can try to kill a process in these states.
2924             break;
2925     }
2926 
2927     if (kill (GetID (), SIGKILL) != 0)
2928     {
2929         error.SetErrorToErrno ();
2930         return error;
2931     }
2932 
2933     return error;
2934 }
2935 
2936 static Error
2937 ParseMemoryRegionInfoFromProcMapsLine (const std::string &maps_line, MemoryRegionInfo &memory_region_info)
2938 {
2939     memory_region_info.Clear();
2940 
2941     StringExtractor line_extractor (maps_line.c_str ());
2942 
2943     // Format: {address_start_hex}-{address_end_hex} perms offset  dev   inode   pathname
2944     // perms: rwxp   (letter is present if set, '-' if not, final character is p=private, s=shared).
2945 
2946     // Parse out the starting address
2947     lldb::addr_t start_address = line_extractor.GetHexMaxU64 (false, 0);
2948 
2949     // Parse out hyphen separating start and end address from range.
2950     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != '-'))
2951         return Error ("malformed /proc/{pid}/maps entry, missing dash between address range");
2952 
2953     // Parse out the ending address
2954     lldb::addr_t end_address = line_extractor.GetHexMaxU64 (false, start_address);
2955 
2956     // Parse out the space after the address.
2957     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != ' '))
2958         return Error ("malformed /proc/{pid}/maps entry, missing space after range");
2959 
2960     // Save the range.
2961     memory_region_info.GetRange ().SetRangeBase (start_address);
2962     memory_region_info.GetRange ().SetRangeEnd (end_address);
2963 
2964     // Parse out each permission entry.
2965     if (line_extractor.GetBytesLeft () < 4)
2966         return Error ("malformed /proc/{pid}/maps entry, missing some portion of permissions");
2967 
2968     // Handle read permission.
2969     const char read_perm_char = line_extractor.GetChar ();
2970     if (read_perm_char == 'r')
2971         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eYes);
2972     else
2973     {
2974         assert ( (read_perm_char == '-') && "unexpected /proc/{pid}/maps read permission char" );
2975         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
2976     }
2977 
2978     // Handle write permission.
2979     const char write_perm_char = line_extractor.GetChar ();
2980     if (write_perm_char == 'w')
2981         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eYes);
2982     else
2983     {
2984         assert ( (write_perm_char == '-') && "unexpected /proc/{pid}/maps write permission char" );
2985         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
2986     }
2987 
2988     // Handle execute permission.
2989     const char exec_perm_char = line_extractor.GetChar ();
2990     if (exec_perm_char == 'x')
2991         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eYes);
2992     else
2993     {
2994         assert ( (exec_perm_char == '-') && "unexpected /proc/{pid}/maps exec permission char" );
2995         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
2996     }
2997 
2998     return Error ();
2999 }
3000 
3001 Error
3002 NativeProcessLinux::GetMemoryRegionInfo (lldb::addr_t load_addr, MemoryRegionInfo &range_info)
3003 {
3004     // FIXME review that the final memory region returned extends to the end of the virtual address space,
3005     // with no perms if it is not mapped.
3006 
3007     // Use an approach that reads memory regions from /proc/{pid}/maps.
3008     // Assume proc maps entries are in ascending order.
3009     // FIXME assert if we find differently.
3010     Mutex::Locker locker (m_mem_region_cache_mutex);
3011 
3012     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3013     Error error;
3014 
3015     if (m_supports_mem_region == LazyBool::eLazyBoolNo)
3016     {
3017         // We're done.
3018         error.SetErrorString ("unsupported");
3019         return error;
3020     }
3021 
3022     // If our cache is empty, pull the latest.  There should always be at least one memory region
3023     // if memory region handling is supported.
3024     if (m_mem_region_cache.empty ())
3025     {
3026         error = ProcFileReader::ProcessLineByLine (GetID (), "maps",
3027              [&] (const std::string &line) -> bool
3028              {
3029                  MemoryRegionInfo info;
3030                  const Error parse_error = ParseMemoryRegionInfoFromProcMapsLine (line, info);
3031                  if (parse_error.Success ())
3032                  {
3033                      m_mem_region_cache.push_back (info);
3034                      return true;
3035                  }
3036                  else
3037                  {
3038                      if (log)
3039                          log->Printf ("NativeProcessLinux::%s failed to parse proc maps line '%s': %s", __FUNCTION__, line.c_str (), error.AsCString ());
3040                      return false;
3041                  }
3042              });
3043 
3044         // If we had an error, we'll mark unsupported.
3045         if (error.Fail ())
3046         {
3047             m_supports_mem_region = LazyBool::eLazyBoolNo;
3048             return error;
3049         }
3050         else if (m_mem_region_cache.empty ())
3051         {
3052             // No entries after attempting to read them.  This shouldn't happen if /proc/{pid}/maps
3053             // is supported.  Assume we don't support map entries via procfs.
3054             if (log)
3055                 log->Printf ("NativeProcessLinux::%s failed to find any procfs maps entries, assuming no support for memory region metadata retrieval", __FUNCTION__);
3056             m_supports_mem_region = LazyBool::eLazyBoolNo;
3057             error.SetErrorString ("not supported");
3058             return error;
3059         }
3060 
3061         if (log)
3062             log->Printf ("NativeProcessLinux::%s read %" PRIu64 " memory region entries from /proc/%" PRIu64 "/maps", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()), GetID ());
3063 
3064         // We support memory retrieval, remember that.
3065         m_supports_mem_region = LazyBool::eLazyBoolYes;
3066     }
3067     else
3068     {
3069         if (log)
3070             log->Printf ("NativeProcessLinux::%s reusing %" PRIu64 " cached memory region entries", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
3071     }
3072 
3073     lldb::addr_t prev_base_address = 0;
3074 
3075     // FIXME start by finding the last region that is <= target address using binary search.  Data is sorted.
3076     // There can be a ton of regions on pthreads apps with lots of threads.
3077     for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end (); ++it)
3078     {
3079         MemoryRegionInfo &proc_entry_info = *it;
3080 
3081         // Sanity check assumption that /proc/{pid}/maps entries are ascending.
3082         assert ((proc_entry_info.GetRange ().GetRangeBase () >= prev_base_address) && "descending /proc/pid/maps entries detected, unexpected");
3083         prev_base_address = proc_entry_info.GetRange ().GetRangeBase ();
3084 
3085         // If the target address comes before this entry, indicate distance to next region.
3086         if (load_addr < proc_entry_info.GetRange ().GetRangeBase ())
3087         {
3088             range_info.GetRange ().SetRangeBase (load_addr);
3089             range_info.GetRange ().SetByteSize (proc_entry_info.GetRange ().GetRangeBase () - load_addr);
3090             range_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
3091             range_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
3092             range_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
3093 
3094             return error;
3095         }
3096         else if (proc_entry_info.GetRange ().Contains (load_addr))
3097         {
3098             // The target address is within the memory region we're processing here.
3099             range_info = proc_entry_info;
3100             return error;
3101         }
3102 
3103         // The target memory address comes somewhere after the region we just parsed.
3104     }
3105 
3106     // If we made it here, we didn't find an entry that contained the given address.
3107     error.SetErrorString ("address comes after final region");
3108 
3109     if (log)
3110         log->Printf ("NativeProcessLinux::%s failed to find map entry for address 0x%" PRIx64 ": %s", __FUNCTION__, load_addr, error.AsCString ());
3111 
3112     return error;
3113 }
3114 
3115 void
3116 NativeProcessLinux::DoStopIDBumped (uint32_t newBumpId)
3117 {
3118     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3119     if (log)
3120         log->Printf ("NativeProcessLinux::%s(newBumpId=%" PRIu32 ") called", __FUNCTION__, newBumpId);
3121 
3122     {
3123         Mutex::Locker locker (m_mem_region_cache_mutex);
3124         if (log)
3125             log->Printf ("NativeProcessLinux::%s clearing %" PRIu64 " entries from the cache", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
3126         m_mem_region_cache.clear ();
3127     }
3128 }
3129 
3130 Error
3131 NativeProcessLinux::AllocateMemory (
3132     lldb::addr_t size,
3133     uint32_t permissions,
3134     lldb::addr_t &addr)
3135 {
3136     // FIXME implementing this requires the equivalent of
3137     // InferiorCallPOSIX::InferiorCallMmap, which depends on
3138     // functional ThreadPlans working with Native*Protocol.
3139 #if 1
3140     return Error ("not implemented yet");
3141 #else
3142     addr = LLDB_INVALID_ADDRESS;
3143 
3144     unsigned prot = 0;
3145     if (permissions & lldb::ePermissionsReadable)
3146         prot |= eMmapProtRead;
3147     if (permissions & lldb::ePermissionsWritable)
3148         prot |= eMmapProtWrite;
3149     if (permissions & lldb::ePermissionsExecutable)
3150         prot |= eMmapProtExec;
3151 
3152     // TODO implement this directly in NativeProcessLinux
3153     // (and lift to NativeProcessPOSIX if/when that class is
3154     // refactored out).
3155     if (InferiorCallMmap(this, addr, 0, size, prot,
3156                          eMmapFlagsAnon | eMmapFlagsPrivate, -1, 0)) {
3157         m_addr_to_mmap_size[addr] = size;
3158         return Error ();
3159     } else {
3160         addr = LLDB_INVALID_ADDRESS;
3161         return Error("unable to allocate %" PRIu64 " bytes of memory with permissions %s", size, GetPermissionsAsCString (permissions));
3162     }
3163 #endif
3164 }
3165 
3166 Error
3167 NativeProcessLinux::DeallocateMemory (lldb::addr_t addr)
3168 {
3169     // FIXME see comments in AllocateMemory - required lower-level
3170     // bits not in place yet (ThreadPlans)
3171     return Error ("not implemented");
3172 }
3173 
3174 lldb::addr_t
3175 NativeProcessLinux::GetSharedLibraryInfoAddress ()
3176 {
3177 #if 1
3178     // punt on this for now
3179     return LLDB_INVALID_ADDRESS;
3180 #else
3181     // Return the image info address for the exe module
3182 #if 1
3183     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3184 
3185     ModuleSP module_sp;
3186     Error error = GetExeModuleSP (module_sp);
3187     if (error.Fail ())
3188     {
3189          if (log)
3190             log->Warning ("NativeProcessLinux::%s failed to retrieve exe module: %s", __FUNCTION__, error.AsCString ());
3191         return LLDB_INVALID_ADDRESS;
3192     }
3193 
3194     if (module_sp == nullptr)
3195     {
3196          if (log)
3197             log->Warning ("NativeProcessLinux::%s exe module returned was NULL", __FUNCTION__);
3198          return LLDB_INVALID_ADDRESS;
3199     }
3200 
3201     ObjectFileSP object_file_sp = module_sp->GetObjectFile ();
3202     if (object_file_sp == nullptr)
3203     {
3204          if (log)
3205             log->Warning ("NativeProcessLinux::%s exe module returned a NULL object file", __FUNCTION__);
3206          return LLDB_INVALID_ADDRESS;
3207     }
3208 
3209     return obj_file_sp->GetImageInfoAddress();
3210 #else
3211     Target *target = &GetTarget();
3212     ObjectFile *obj_file = target->GetExecutableModule()->GetObjectFile();
3213     Address addr = obj_file->GetImageInfoAddress(target);
3214 
3215     if (addr.IsValid())
3216         return addr.GetLoadAddress(target);
3217     return LLDB_INVALID_ADDRESS;
3218 #endif
3219 #endif // punt on this for now
3220 }
3221 
3222 size_t
3223 NativeProcessLinux::UpdateThreads ()
3224 {
3225     // The NativeProcessLinux monitoring threads are always up to date
3226     // with respect to thread state and they keep the thread list
3227     // populated properly. All this method needs to do is return the
3228     // thread count.
3229     Mutex::Locker locker (m_threads_mutex);
3230     return m_threads.size ();
3231 }
3232 
3233 bool
3234 NativeProcessLinux::GetArchitecture (ArchSpec &arch) const
3235 {
3236     arch = m_arch;
3237     return true;
3238 }
3239 
3240 Error
3241 NativeProcessLinux::GetSoftwareBreakpointSize (NativeRegisterContextSP context_sp, uint32_t &actual_opcode_size)
3242 {
3243     // FIXME put this behind a breakpoint protocol class that can be
3244     // set per architecture.  Need ARM, MIPS support here.
3245     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
3246     static const uint8_t g_i386_opcode [] = { 0xCC };
3247 
3248     switch (m_arch.GetMachine ())
3249     {
3250         case llvm::Triple::aarch64:
3251             actual_opcode_size = static_cast<uint32_t> (sizeof(g_aarch64_opcode));
3252             return Error ();
3253 
3254         case llvm::Triple::x86:
3255         case llvm::Triple::x86_64:
3256             actual_opcode_size = static_cast<uint32_t> (sizeof(g_i386_opcode));
3257             return Error ();
3258 
3259         default:
3260             assert(false && "CPU type not supported!");
3261             return Error ("CPU type not supported");
3262     }
3263 }
3264 
3265 Error
3266 NativeProcessLinux::SetBreakpoint (lldb::addr_t addr, uint32_t size, bool hardware)
3267 {
3268     if (hardware)
3269         return Error ("NativeProcessLinux does not support hardware breakpoints");
3270     else
3271         return SetSoftwareBreakpoint (addr, size);
3272 }
3273 
3274 Error
3275 NativeProcessLinux::GetSoftwareBreakpointTrapOpcode (size_t trap_opcode_size_hint, size_t &actual_opcode_size, const uint8_t *&trap_opcode_bytes)
3276 {
3277     // FIXME put this behind a breakpoint protocol class that can be
3278     // set per architecture.  Need ARM, MIPS support here.
3279     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
3280     static const uint8_t g_i386_opcode [] = { 0xCC };
3281 
3282     switch (m_arch.GetMachine ())
3283     {
3284     case llvm::Triple::aarch64:
3285         trap_opcode_bytes = g_aarch64_opcode;
3286         actual_opcode_size = sizeof(g_aarch64_opcode);
3287         return Error ();
3288 
3289     case llvm::Triple::x86:
3290     case llvm::Triple::x86_64:
3291         trap_opcode_bytes = g_i386_opcode;
3292         actual_opcode_size = sizeof(g_i386_opcode);
3293         return Error ();
3294 
3295     default:
3296         assert(false && "CPU type not supported!");
3297         return Error ("CPU type not supported");
3298     }
3299 }
3300 
3301 #if 0
3302 ProcessMessage::CrashReason
3303 NativeProcessLinux::GetCrashReasonForSIGSEGV(const siginfo_t *info)
3304 {
3305     ProcessMessage::CrashReason reason;
3306     assert(info->si_signo == SIGSEGV);
3307 
3308     reason = ProcessMessage::eInvalidCrashReason;
3309 
3310     switch (info->si_code)
3311     {
3312     default:
3313         assert(false && "unexpected si_code for SIGSEGV");
3314         break;
3315     case SI_KERNEL:
3316         // Linux will occasionally send spurious SI_KERNEL codes.
3317         // (this is poorly documented in sigaction)
3318         // One way to get this is via unaligned SIMD loads.
3319         reason = ProcessMessage::eInvalidAddress; // for lack of anything better
3320         break;
3321     case SEGV_MAPERR:
3322         reason = ProcessMessage::eInvalidAddress;
3323         break;
3324     case SEGV_ACCERR:
3325         reason = ProcessMessage::ePrivilegedAddress;
3326         break;
3327     }
3328 
3329     return reason;
3330 }
3331 #endif
3332 
3333 
3334 #if 0
3335 ProcessMessage::CrashReason
3336 NativeProcessLinux::GetCrashReasonForSIGILL(const siginfo_t *info)
3337 {
3338     ProcessMessage::CrashReason reason;
3339     assert(info->si_signo == SIGILL);
3340 
3341     reason = ProcessMessage::eInvalidCrashReason;
3342 
3343     switch (info->si_code)
3344     {
3345     default:
3346         assert(false && "unexpected si_code for SIGILL");
3347         break;
3348     case ILL_ILLOPC:
3349         reason = ProcessMessage::eIllegalOpcode;
3350         break;
3351     case ILL_ILLOPN:
3352         reason = ProcessMessage::eIllegalOperand;
3353         break;
3354     case ILL_ILLADR:
3355         reason = ProcessMessage::eIllegalAddressingMode;
3356         break;
3357     case ILL_ILLTRP:
3358         reason = ProcessMessage::eIllegalTrap;
3359         break;
3360     case ILL_PRVOPC:
3361         reason = ProcessMessage::ePrivilegedOpcode;
3362         break;
3363     case ILL_PRVREG:
3364         reason = ProcessMessage::ePrivilegedRegister;
3365         break;
3366     case ILL_COPROC:
3367         reason = ProcessMessage::eCoprocessorError;
3368         break;
3369     case ILL_BADSTK:
3370         reason = ProcessMessage::eInternalStackError;
3371         break;
3372     }
3373 
3374     return reason;
3375 }
3376 #endif
3377 
3378 #if 0
3379 ProcessMessage::CrashReason
3380 NativeProcessLinux::GetCrashReasonForSIGFPE(const siginfo_t *info)
3381 {
3382     ProcessMessage::CrashReason reason;
3383     assert(info->si_signo == SIGFPE);
3384 
3385     reason = ProcessMessage::eInvalidCrashReason;
3386 
3387     switch (info->si_code)
3388     {
3389     default:
3390         assert(false && "unexpected si_code for SIGFPE");
3391         break;
3392     case FPE_INTDIV:
3393         reason = ProcessMessage::eIntegerDivideByZero;
3394         break;
3395     case FPE_INTOVF:
3396         reason = ProcessMessage::eIntegerOverflow;
3397         break;
3398     case FPE_FLTDIV:
3399         reason = ProcessMessage::eFloatDivideByZero;
3400         break;
3401     case FPE_FLTOVF:
3402         reason = ProcessMessage::eFloatOverflow;
3403         break;
3404     case FPE_FLTUND:
3405         reason = ProcessMessage::eFloatUnderflow;
3406         break;
3407     case FPE_FLTRES:
3408         reason = ProcessMessage::eFloatInexactResult;
3409         break;
3410     case FPE_FLTINV:
3411         reason = ProcessMessage::eFloatInvalidOperation;
3412         break;
3413     case FPE_FLTSUB:
3414         reason = ProcessMessage::eFloatSubscriptRange;
3415         break;
3416     }
3417 
3418     return reason;
3419 }
3420 #endif
3421 
3422 #if 0
3423 ProcessMessage::CrashReason
3424 NativeProcessLinux::GetCrashReasonForSIGBUS(const siginfo_t *info)
3425 {
3426     ProcessMessage::CrashReason reason;
3427     assert(info->si_signo == SIGBUS);
3428 
3429     reason = ProcessMessage::eInvalidCrashReason;
3430 
3431     switch (info->si_code)
3432     {
3433     default:
3434         assert(false && "unexpected si_code for SIGBUS");
3435         break;
3436     case BUS_ADRALN:
3437         reason = ProcessMessage::eIllegalAlignment;
3438         break;
3439     case BUS_ADRERR:
3440         reason = ProcessMessage::eIllegalAddress;
3441         break;
3442     case BUS_OBJERR:
3443         reason = ProcessMessage::eHardwareError;
3444         break;
3445     }
3446 
3447     return reason;
3448 }
3449 #endif
3450 
3451 void
3452 NativeProcessLinux::ServeOperation(OperationArgs *args)
3453 {
3454     NativeProcessLinux *monitor = args->m_monitor;
3455 
3456     // We are finised with the arguments and are ready to go.  Sync with the
3457     // parent thread and start serving operations on the inferior.
3458     sem_post(&args->m_semaphore);
3459 
3460     for(;;)
3461     {
3462         // wait for next pending operation
3463         if (sem_wait(&monitor->m_operation_pending))
3464         {
3465             if (errno == EINTR)
3466                 continue;
3467             assert(false && "Unexpected errno from sem_wait");
3468         }
3469 
3470         reinterpret_cast<Operation*>(monitor->m_operation)->Execute(monitor);
3471 
3472         // notify calling thread that operation is complete
3473         sem_post(&monitor->m_operation_done);
3474     }
3475 }
3476 
3477 void
3478 NativeProcessLinux::DoOperation(void *op)
3479 {
3480     Mutex::Locker lock(m_operation_mutex);
3481 
3482     m_operation = op;
3483 
3484     // notify operation thread that an operation is ready to be processed
3485     sem_post(&m_operation_pending);
3486 
3487     // wait for operation to complete
3488     while (sem_wait(&m_operation_done))
3489     {
3490         if (errno == EINTR)
3491             continue;
3492         assert(false && "Unexpected errno from sem_wait");
3493     }
3494 }
3495 
3496 Error
3497 NativeProcessLinux::ReadMemory (lldb::addr_t addr, void *buf, lldb::addr_t size, lldb::addr_t &bytes_read)
3498 {
3499     ReadOperation op(addr, buf, size, bytes_read);
3500     DoOperation(&op);
3501     return op.GetError ();
3502 }
3503 
3504 Error
3505 NativeProcessLinux::WriteMemory (lldb::addr_t addr, const void *buf, lldb::addr_t size, lldb::addr_t &bytes_written)
3506 {
3507     WriteOperation op(addr, buf, size, bytes_written);
3508     DoOperation(&op);
3509     return op.GetError ();
3510 }
3511 
3512 bool
3513 NativeProcessLinux::ReadRegisterValue(lldb::tid_t tid, uint32_t offset, const char* reg_name,
3514                                   uint32_t size, RegisterValue &value)
3515 {
3516     bool result;
3517     ReadRegOperation op(tid, offset, reg_name, value, result);
3518     DoOperation(&op);
3519     return result;
3520 }
3521 
3522 bool
3523 NativeProcessLinux::WriteRegisterValue(lldb::tid_t tid, unsigned offset,
3524                                    const char* reg_name, const RegisterValue &value)
3525 {
3526     bool result;
3527     WriteRegOperation op(tid, offset, reg_name, value, result);
3528     DoOperation(&op);
3529     return result;
3530 }
3531 
3532 bool
3533 NativeProcessLinux::ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3534 {
3535     bool result;
3536     ReadGPROperation op(tid, buf, buf_size, result);
3537     DoOperation(&op);
3538     return result;
3539 }
3540 
3541 bool
3542 NativeProcessLinux::ReadFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3543 {
3544     bool result;
3545     ReadFPROperation op(tid, buf, buf_size, result);
3546     DoOperation(&op);
3547     return result;
3548 }
3549 
3550 bool
3551 NativeProcessLinux::ReadRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3552 {
3553     bool result;
3554     ReadRegisterSetOperation op(tid, buf, buf_size, regset, result);
3555     DoOperation(&op);
3556     return result;
3557 }
3558 
3559 bool
3560 NativeProcessLinux::WriteGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3561 {
3562     bool result;
3563     WriteGPROperation op(tid, buf, buf_size, result);
3564     DoOperation(&op);
3565     return result;
3566 }
3567 
3568 bool
3569 NativeProcessLinux::WriteFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3570 {
3571     bool result;
3572     WriteFPROperation op(tid, buf, buf_size, result);
3573     DoOperation(&op);
3574     return result;
3575 }
3576 
3577 bool
3578 NativeProcessLinux::WriteRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3579 {
3580     bool result;
3581     WriteRegisterSetOperation op(tid, buf, buf_size, regset, result);
3582     DoOperation(&op);
3583     return result;
3584 }
3585 
3586 bool
3587 NativeProcessLinux::Resume (lldb::tid_t tid, uint32_t signo)
3588 {
3589     bool result;
3590     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3591 
3592     if (log)
3593         log->Printf ("NativeProcessLinux::%s() resuming thread = %"  PRIu64 " with signal %s", __FUNCTION__, tid,
3594                                  GetUnixSignals().GetSignalAsCString (signo));
3595     ResumeOperation op (tid, signo, result);
3596     DoOperation (&op);
3597     if (log)
3598         log->Printf ("NativeProcessLinux::%s() resuming result = %s", __FUNCTION__, result ? "true" : "false");
3599     return result;
3600 }
3601 
3602 bool
3603 NativeProcessLinux::SingleStep(lldb::tid_t tid, uint32_t signo)
3604 {
3605     bool result;
3606     SingleStepOperation op(tid, signo, result);
3607     DoOperation(&op);
3608     return result;
3609 }
3610 
3611 bool
3612 NativeProcessLinux::GetSignalInfo(lldb::tid_t tid, void *siginfo, int &ptrace_err)
3613 {
3614     bool result;
3615     SiginfoOperation op(tid, siginfo, result, ptrace_err);
3616     DoOperation(&op);
3617     return result;
3618 }
3619 
3620 bool
3621 NativeProcessLinux::GetEventMessage(lldb::tid_t tid, unsigned long *message)
3622 {
3623     bool result;
3624     EventMessageOperation op(tid, message, result);
3625     DoOperation(&op);
3626     return result;
3627 }
3628 
3629 lldb_private::Error
3630 NativeProcessLinux::Detach(lldb::tid_t tid)
3631 {
3632     lldb_private::Error error;
3633     if (tid != LLDB_INVALID_THREAD_ID)
3634     {
3635         DetachOperation op(tid, error);
3636         DoOperation(&op);
3637     }
3638     return error;
3639 }
3640 
3641 bool
3642 NativeProcessLinux::DupDescriptor(const char *path, int fd, int flags)
3643 {
3644     int target_fd = open(path, flags, 0666);
3645 
3646     if (target_fd == -1)
3647         return false;
3648 
3649     return (dup2(target_fd, fd) == -1) ? false : true;
3650 }
3651 
3652 void
3653 NativeProcessLinux::StopMonitoringChildProcess()
3654 {
3655     if (m_monitor_thread.IsJoinable())
3656     {
3657         m_monitor_thread.Cancel();
3658         m_monitor_thread.Join(nullptr);
3659     }
3660 }
3661 
3662 void
3663 NativeProcessLinux::StopMonitor()
3664 {
3665     StopMonitoringChildProcess();
3666     StopOpThread();
3667     sem_destroy(&m_operation_pending);
3668     sem_destroy(&m_operation_done);
3669 
3670     // TODO: validate whether this still holds, fix up comment.
3671     // Note: ProcessPOSIX passes the m_terminal_fd file descriptor to
3672     // Process::SetSTDIOFileDescriptor, which in turn transfers ownership of
3673     // the descriptor to a ConnectionFileDescriptor object.  Consequently
3674     // even though still has the file descriptor, we shouldn't close it here.
3675 }
3676 
3677 void
3678 NativeProcessLinux::StopOpThread()
3679 {
3680     if (!m_operation_thread.IsJoinable())
3681         return;
3682 
3683     m_operation_thread.Cancel();
3684     m_operation_thread.Join(nullptr);
3685 }
3686 
3687 bool
3688 NativeProcessLinux::HasThreadNoLock (lldb::tid_t thread_id)
3689 {
3690     for (auto thread_sp : m_threads)
3691     {
3692         assert (thread_sp && "thread list should not contain NULL threads");
3693         if (thread_sp->GetID () == thread_id)
3694         {
3695             // We have this thread.
3696             return true;
3697         }
3698     }
3699 
3700     // We don't have this thread.
3701     return false;
3702 }
3703 
3704 NativeThreadProtocolSP
3705 NativeProcessLinux::MaybeGetThreadNoLock (lldb::tid_t thread_id)
3706 {
3707     // CONSIDER organize threads by map - we can do better than linear.
3708     for (auto thread_sp : m_threads)
3709     {
3710         if (thread_sp->GetID () == thread_id)
3711             return thread_sp;
3712     }
3713 
3714     // We don't have this thread.
3715     return NativeThreadProtocolSP ();
3716 }
3717 
3718 bool
3719 NativeProcessLinux::StopTrackingThread (lldb::tid_t thread_id)
3720 {
3721     Mutex::Locker locker (m_threads_mutex);
3722     for (auto it = m_threads.begin (); it != m_threads.end (); ++it)
3723     {
3724         if (*it && ((*it)->GetID () == thread_id))
3725         {
3726             m_threads.erase (it);
3727             return true;
3728         }
3729     }
3730 
3731     // Didn't find it.
3732     return false;
3733 }
3734 
3735 NativeThreadProtocolSP
3736 NativeProcessLinux::AddThread (lldb::tid_t thread_id)
3737 {
3738     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3739 
3740     Mutex::Locker locker (m_threads_mutex);
3741 
3742     if (log)
3743     {
3744         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " adding thread with tid %" PRIu64,
3745                 __FUNCTION__,
3746                 GetID (),
3747                 thread_id);
3748     }
3749 
3750     assert (!HasThreadNoLock (thread_id) && "attempted to add a thread by id that already exists");
3751 
3752     // If this is the first thread, save it as the current thread
3753     if (m_threads.empty ())
3754         SetCurrentThreadID (thread_id);
3755 
3756     NativeThreadProtocolSP thread_sp (new NativeThreadLinux (this, thread_id));
3757     m_threads.push_back (thread_sp);
3758 
3759     return thread_sp;
3760 }
3761 
3762 NativeThreadProtocolSP
3763 NativeProcessLinux::GetOrCreateThread (lldb::tid_t thread_id, bool &created)
3764 {
3765     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3766 
3767     Mutex::Locker locker (m_threads_mutex);
3768     if (log)
3769     {
3770         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " get/create thread with tid %" PRIu64,
3771                      __FUNCTION__,
3772                      GetID (),
3773                      thread_id);
3774     }
3775 
3776     // Retrieve the thread if it is already getting tracked.
3777     NativeThreadProtocolSP thread_sp = MaybeGetThreadNoLock (thread_id);
3778     if (thread_sp)
3779     {
3780         if (log)
3781             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread already tracked, returning",
3782                          __FUNCTION__,
3783                          GetID (),
3784                          thread_id);
3785         created = false;
3786         return thread_sp;
3787 
3788     }
3789 
3790     // Create the thread metadata since it isn't being tracked.
3791     if (log)
3792         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread didn't exist, tracking now",
3793                      __FUNCTION__,
3794                      GetID (),
3795                      thread_id);
3796 
3797     thread_sp.reset (new NativeThreadLinux (this, thread_id));
3798     m_threads.push_back (thread_sp);
3799     created = true;
3800 
3801     return thread_sp;
3802 }
3803 
3804 Error
3805 NativeProcessLinux::FixupBreakpointPCAsNeeded (NativeThreadProtocolSP &thread_sp)
3806 {
3807     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3808 
3809     Error error;
3810 
3811     // Get a linux thread pointer.
3812     if (!thread_sp)
3813     {
3814         error.SetErrorString ("null thread_sp");
3815         if (log)
3816             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3817         return error;
3818     }
3819     NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get());
3820 
3821     // Find out the size of a breakpoint (might depend on where we are in the code).
3822     NativeRegisterContextSP context_sp = linux_thread_p->GetRegisterContext ();
3823     if (!context_sp)
3824     {
3825         error.SetErrorString ("cannot get a NativeRegisterContext for the thread");
3826         if (log)
3827             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3828         return error;
3829     }
3830 
3831     uint32_t breakpoint_size = 0;
3832     error = GetSoftwareBreakpointSize (context_sp, breakpoint_size);
3833     if (error.Fail ())
3834     {
3835         if (log)
3836             log->Printf ("NativeProcessLinux::%s GetBreakpointSize() failed: %s", __FUNCTION__, error.AsCString ());
3837         return error;
3838     }
3839     else
3840     {
3841         if (log)
3842             log->Printf ("NativeProcessLinux::%s breakpoint size: %" PRIu32, __FUNCTION__, breakpoint_size);
3843     }
3844 
3845     // First try probing for a breakpoint at a software breakpoint location: PC - breakpoint size.
3846     const lldb::addr_t initial_pc_addr = context_sp->GetPC ();
3847     lldb::addr_t breakpoint_addr = initial_pc_addr;
3848     if (breakpoint_size > static_cast<lldb::addr_t> (0))
3849     {
3850         // Do not allow breakpoint probe to wrap around.
3851         if (breakpoint_addr >= static_cast<lldb::addr_t> (breakpoint_size))
3852             breakpoint_addr -= static_cast<lldb::addr_t> (breakpoint_size);
3853     }
3854 
3855     // Check if we stopped because of a breakpoint.
3856     NativeBreakpointSP breakpoint_sp;
3857     error = m_breakpoint_list.GetBreakpoint (breakpoint_addr, breakpoint_sp);
3858     if (!error.Success () || !breakpoint_sp)
3859     {
3860         // We didn't find one at a software probe location.  Nothing to do.
3861         if (log)
3862             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " no lldb breakpoint found at current pc with adjustment: 0x%" PRIx64, __FUNCTION__, GetID (), breakpoint_addr);
3863         return Error ();
3864     }
3865 
3866     // If the breakpoint is not a software breakpoint, nothing to do.
3867     if (!breakpoint_sp->IsSoftwareBreakpoint ())
3868     {
3869         if (log)
3870             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " breakpoint found at 0x%" PRIx64 ", not software, nothing to adjust", __FUNCTION__, GetID (), breakpoint_addr);
3871         return Error ();
3872     }
3873 
3874     //
3875     // We have a software breakpoint and need to adjust the PC.
3876     //
3877 
3878     // Sanity check.
3879     if (breakpoint_size == 0)
3880     {
3881         // Nothing to do!  How did we get here?
3882         if (log)
3883             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);
3884         return Error ();
3885     }
3886 
3887     // Change the program counter.
3888     if (log)
3889         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);
3890 
3891     error = context_sp->SetPC (breakpoint_addr);
3892     if (error.Fail ())
3893     {
3894         if (log)
3895             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": failed to set PC: %s", __FUNCTION__, GetID (), linux_thread_p->GetID (), error.AsCString ());
3896         return error;
3897     }
3898 
3899     return error;
3900 }
3901