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