Logo AND Algorithmique Numérique Distribuée

Public GIT Repository
Use addr2line as a fallback for stacktraces when backtrace is not available
[simgrid.git] / src / mc / remote / RemoteClient.cpp
1 /* Copyright (c) 2014-2019. The SimGrid Team. All rights reserved.          */
2
3 /* This program is free software; you can redistribute it and/or modify it
4  * under the terms of the license (GNU LGPL) which comes with this package. */
5
6 #define _FILE_OFFSET_BITS 64 /* needed for pread_whole to work as expected on 32bits */
7
8 #include "src/mc/remote/RemoteClient.hpp"
9
10 #include "xbt/file.hpp"
11 #include "xbt/log.h"
12 #include "src/mc/mc_smx.hpp"
13 #include "src/mc/sosp/mc_snapshot.hpp"
14
15 #include <fcntl.h>
16 #include <libunwind-ptrace.h>
17 #include <sys/mman.h> // PROT_*
18
19 using simgrid::mc::remote;
20
21 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
22
23 namespace simgrid {
24 namespace mc {
25
26 // ***** Helper stuff
27
28 // List of library which memory segments are not considered:
29 static const std::vector<std::string> filtered_libraries = {
30 #ifdef __linux__
31     "ld",
32 #elif defined __FreeBSD__
33     "ld-elf",
34     "ld-elf32",
35     "libkvm",      /* kernel data access library */
36     "libprocstat", /* process and file information retrieval */
37     "libthr",      /* thread library */
38     "libutil",
39 #endif
40     "libargp", /* workarounds for glibc-less systems */
41     "libasan", /* gcc sanitizers */
42     "libboost_chrono",
43     "libboost_context",
44     "libboost_context-mt",
45     "libboost_stacktrace_addr2line",
46     "libboost_stacktrace_backtrace",
47     "libboost_system",
48     "libboost_thread",
49     "libboost_timer",
50     "libbz2",
51     "libc",
52     "libc++",
53     "libcdt",
54     "libcgraph",
55     "libcrypto",
56     "libcxxrt",
57     "libdl",
58     "libdw",
59     "libelf",
60     "libevent",
61     "libexecinfo",
62     "libflang",
63     "libflangrti",
64     "libgcc_s",
65     "libgfortran",
66     "libimf",
67     "libintlc",
68     "libirng",
69     "liblua5.1",
70     "liblua5.3",
71     "liblzma",
72     "libm",
73     "libomp",
74     "libpapi",
75     "libpfm",
76     "libpgmath",
77     "libpthread",
78     "libquadmath",
79     "librt",
80     "libstdc++",
81     "libsvml",
82     "libtsan",  /* gcc sanitizers */
83     "libubsan", /* gcc sanitizers */
84     "libunwind",
85     "libunwind-ptrace",
86     "libunwind-x86",
87     "libunwind-x86_64",
88     "libz"};
89
90 static bool is_simgrid_lib(const std::string& libname)
91 {
92   return libname == "libsimgrid";
93 }
94
95 static bool is_filtered_lib(const std::string& libname)
96 {
97   return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
98 }
99
100 static std::string get_lib_name(const std::string& pathname)
101 {
102   std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
103   std::string libname;
104
105   size_t pos = map_basename.rfind(".so");
106   if (pos != std::string::npos) {
107     // strip the extension (matching regex "\.so.*$")
108     libname.assign(map_basename, 0, pos);
109
110     // strip the version suffix (matching regex "-[.0-9-]*$")
111     while (true) {
112       pos = libname.rfind('-');
113       if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
114         break;
115       libname.erase(pos);
116     }
117   }
118
119   return libname;
120 }
121
122 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
123 {
124   char* buffer       = (char*)buf;
125   ssize_t real_count = count;
126   while (count) {
127     ssize_t res = pread(fd, buffer, count, offset);
128     if (res > 0) {
129       count -= res;
130       buffer += res;
131       offset += res;
132     } else if (res == 0)
133       return -1;
134     else if (errno != EINTR) {
135       perror("pread_whole");
136       return -1;
137     }
138   }
139   return real_count;
140 }
141
142 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
143 {
144   const char* buffer = (const char*)buf;
145   ssize_t real_count = count;
146   while (count) {
147     ssize_t res = pwrite(fd, buffer, count, offset);
148     if (res > 0) {
149       count -= res;
150       buffer += res;
151       offset += res;
152     } else if (res == 0)
153       return -1;
154     else if (errno != EINTR)
155       return -1;
156   }
157   return real_count;
158 }
159
160 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
161 static const void* zero_buffer;
162 static const size_t zero_buffer_size = 10 * 4096;
163
164 static void zero_buffer_init()
165 {
166   int fd = open("/dev/zero", O_RDONLY);
167   if (fd < 0)
168     xbt_die("Could not open /dev/zero");
169   zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
170   if (zero_buffer == MAP_FAILED)
171     xbt_die("Could not map the zero buffer");
172   close(fd);
173 }
174
175 int open_vm(pid_t pid, int flags)
176 {
177   const size_t buffer_size = 30;
178   char buffer[buffer_size];
179   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long)pid);
180   if (res < 0 || (size_t)res >= buffer_size) {
181     errno = ENAMETOOLONG;
182     return -1;
183   }
184   return open(buffer, flags);
185 }
186
187 // ***** Process
188
189 RemoteClient::RemoteClient(pid_t pid, int sockfd) : AddressSpace(this), pid_(pid), channel_(sockfd), running_(true)
190 {
191 }
192
193 void RemoteClient::init()
194 {
195   this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
196   this->init_memory_map_info();
197
198   int fd = open_vm(this->pid_, O_RDWR);
199   if (fd < 0)
200     xbt_die("Could not open file for process virtual address space");
201   this->memory_file = fd;
202
203   // Read std_heap (is a struct mdesc*):
204   const simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
205   if (not std_heap_var)
206     xbt_die("No heap information in the target process");
207   if (not std_heap_var->address)
208     xbt_die("No constant address for this variable");
209   this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address),
210                    simgrid::mc::ProcessIndexDisabled);
211
212   this->smx_actors_infos.clear();
213   this->smx_dead_actors_infos.clear();
214   this->unw_addr_space            = simgrid::mc::UnwindContext::createUnwindAddressSpace();
215   this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
216   this->unw_underlying_context    = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
217 }
218
219 RemoteClient::~RemoteClient()
220 {
221   if (this->memory_file >= 0)
222     close(this->memory_file);
223
224   if (this->unw_underlying_addr_space != unw_local_addr_space) {
225     if (this->unw_underlying_addr_space)
226       unw_destroy_addr_space(this->unw_underlying_addr_space);
227     if (this->unw_underlying_context)
228       _UPT_destroy(this->unw_underlying_context);
229   }
230
231   unw_destroy_addr_space(this->unw_addr_space);
232 }
233
234 /** Refresh the information about the process
235  *
236  *  Do not use directly, this is used by the getters when appropriate
237  *  in order to have fresh data.
238  */
239 void RemoteClient::refresh_heap()
240 {
241   // Read/dereference/refresh the std_heap pointer:
242   if (not this->heap)
243     this->heap.reset(new s_xbt_mheap_t());
244   this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address), simgrid::mc::ProcessIndexDisabled);
245   this->cache_flags_ |= RemoteClient::cache_heap;
246 }
247
248 /** Refresh the information about the process
249  *
250  *  Do not use direclty, this is used by the getters when appropriate
251  *  in order to have fresh data.
252  * */
253 void RemoteClient::refresh_malloc_info()
254 {
255   // Refresh process->heapinfo:
256   if (this->cache_flags_ & RemoteClient::cache_malloc)
257     return;
258   size_t count = this->heap->heaplimit + 1;
259   if (this->heap_info.size() < count)
260     this->heap_info.resize(count);
261   this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo),
262                    simgrid::mc::ProcessIndexDisabled);
263   this->cache_flags_ |= RemoteClient::cache_malloc;
264 }
265
266 /** @brief Finds the range of the different memory segments and binary paths */
267 void RemoteClient::init_memory_map_info()
268 {
269   XBT_DEBUG("Get debug information ...");
270   this->maestro_stack_start_ = nullptr;
271   this->maestro_stack_end_   = nullptr;
272   this->object_infos.resize(0);
273   this->binary_info     = nullptr;
274   this->libsimgrid_info = nullptr;
275
276   std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
277
278   const char* current_name = nullptr;
279
280   this->object_infos.clear();
281
282   for (size_t i = 0; i < maps.size(); i++) {
283     simgrid::xbt::VmMap const& reg = maps[i];
284     const char* pathname           = maps[i].pathname.c_str();
285
286     // Nothing to do
287     if (maps[i].pathname.empty()) {
288       current_name = nullptr;
289       continue;
290     }
291
292     // [stack], [vvar], [vsyscall], [vdso] ...
293     if (pathname[0] == '[') {
294       if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
295         this->maestro_stack_start_ = remote(reg.start_addr);
296         this->maestro_stack_end_   = remote(reg.end_addr);
297       }
298       current_name = nullptr;
299       continue;
300     }
301
302     if (current_name && strcmp(current_name, pathname) == 0)
303       continue;
304
305     current_name = pathname;
306     if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
307       continue;
308
309     const bool is_executable = not i;
310     std::string libname;
311     if (not is_executable) {
312       libname = get_lib_name(pathname);
313       if (is_filtered_lib(libname)) {
314         continue;
315       }
316     }
317
318     std::shared_ptr<simgrid::mc::ObjectInformation> info =
319         simgrid::mc::createObjectInformation(this->memory_map_, pathname);
320     this->object_infos.push_back(info);
321     if (is_executable)
322       this->binary_info = info;
323     else if (is_simgrid_lib(libname))
324       this->libsimgrid_info = info;
325   }
326
327   // Resolve time (including across different objects):
328   for (auto const& object_info : this->object_infos)
329     postProcessObjectInformation(this, object_info.get());
330
331   xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
332   xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
333
334   XBT_DEBUG("Get debug information done !");
335 }
336
337 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteClient::find_object_info(RemotePtr<void> addr) const
338 {
339   for (auto const& object_info : this->object_infos)
340     if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
341       return object_info;
342   return nullptr;
343 }
344
345 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_exec(RemotePtr<void> addr) const
346 {
347   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
348     if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
349       return info;
350   return nullptr;
351 }
352
353 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_rw(RemotePtr<void> addr) const
354 {
355   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
356     if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
357       return info;
358   return nullptr;
359 }
360
361 simgrid::mc::Frame* RemoteClient::find_function(RemotePtr<void> ip) const
362 {
363   std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
364   return info ? info->find_function((void*)ip.address()) : nullptr;
365 }
366
367 /** Find (one occurrence of) the named variable definition
368  */
369 const simgrid::mc::Variable* RemoteClient::find_variable(const char* name) const
370 {
371   // First lookup the variable in the executable shared object.
372   // A global variable used directly by the executable code from a library
373   // is reinstanciated in the executable memory .data/.bss.
374   // We need to look up the variable in the executable first.
375   if (this->binary_info) {
376     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
377     const simgrid::mc::Variable* var                            = info->find_variable(name);
378     if (var)
379       return var;
380   }
381
382   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
383     const simgrid::mc::Variable* var = info->find_variable(name);
384     if (var)
385       return var;
386   }
387
388   return nullptr;
389 }
390
391 void RemoteClient::read_variable(const char* name, void* target, size_t size) const
392 {
393   const simgrid::mc::Variable* var = this->find_variable(name);
394   xbt_assert(var->address, "No simple location for this variable");
395   xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
396   xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
397              size, (size_t)var->type->full_type->byte_size);
398   this->read_bytes(target, size, remote(var->address));
399 }
400
401 std::string RemoteClient::read_string(RemotePtr<char> address) const
402 {
403   if (not address)
404     return {};
405
406   std::vector<char> res(128);
407   off_t off = 0;
408
409   while (1) {
410     ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
411     if (c == -1) {
412       if (errno == EINTR)
413         continue;
414       else
415         xbt_die("Could not read from from remote process");
416     }
417     if (c == 0)
418       xbt_die("Could not read string from remote process");
419
420     void* p = memchr(res.data() + off, '\0', c);
421     if (p)
422       return std::string(res.data());
423
424     off += c;
425     if (off == (off_t)res.size())
426       res.resize(res.size() * 2);
427   }
428 }
429
430 const void* RemoteClient::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address, int process_index,
431                                      ReadOptions /*options*/) const
432 {
433 #if HAVE_SMPI
434   if (process_index != simgrid::mc::ProcessIndexDisabled) {
435     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->find_object_info_rw(address);
436     // Segment overlap is not handled.
437     if (info.get() && this->privatized(*info)) {
438       if (process_index < 0)
439         xbt_die("Missing process index");
440       if (process_index >= (int)MC_smpi_process_count())
441         xbt_die("Invalid process index");
442
443       // Read smpi_privatization_regions from MCed:
444       smpi_privatization_region_t remote_smpi_privatization_regions =
445           mc_model_checker->process().read_variable<smpi_privatization_region_t>("smpi_privatization_regions");
446
447       s_smpi_privatization_region_t privatization_region =
448           mc_model_checker->process().read<s_smpi_privatization_region_t>(
449               remote(remote_smpi_privatization_regions + process_index));
450
451       // Address translation in the privatization segment:
452       size_t offset = address.address() - (std::uint64_t)info->start_rw;
453       address       = remote((char*)privatization_region.address + offset);
454     }
455   }
456 #endif
457   if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
458     xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
459   return buffer;
460 }
461
462 /** Write data to a process memory
463  *
464  *  @param buffer   local memory address (source)
465  *  @param len      data size
466  *  @param address  target process memory address (target)
467  */
468 void RemoteClient::write_bytes(const void* buffer, size_t len, RemotePtr<void> address)
469 {
470   if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
471     xbt_die("Write to process %lli failed", (long long)this->pid_);
472 }
473
474 void RemoteClient::clear_bytes(RemotePtr<void> address, size_t len)
475 {
476   pthread_once(&zero_buffer_flag, zero_buffer_init);
477   while (len) {
478     size_t s = len > zero_buffer_size ? zero_buffer_size : len;
479     this->write_bytes(zero_buffer, s, address);
480     address = remote((char*)address.address() + s);
481     len -= s;
482   }
483 }
484
485 void RemoteClient::ignore_region(std::uint64_t addr, std::size_t size)
486 {
487   IgnoredRegion region;
488   region.addr = addr;
489   region.size = size;
490
491   if (ignored_regions_.empty()) {
492     ignored_regions_.push_back(region);
493     return;
494   }
495
496   unsigned int cursor           = 0;
497   IgnoredRegion* current_region = nullptr;
498
499   int start = 0;
500   int end   = ignored_regions_.size() - 1;
501   while (start <= end) {
502     cursor         = (start + end) / 2;
503     current_region = &ignored_regions_[cursor];
504     if (current_region->addr == addr) {
505       if (current_region->size == size)
506         return;
507       else if (current_region->size < size)
508         start = cursor + 1;
509       else
510         end = cursor - 1;
511     } else if (current_region->addr < addr)
512       start = cursor + 1;
513     else
514       end = cursor - 1;
515   }
516
517   std::size_t position;
518   if (current_region->addr == addr) {
519     if (current_region->size < size)
520       position = cursor + 1;
521     else
522       position = cursor;
523   } else if (current_region->addr < addr)
524     position = cursor + 1;
525   else
526     position = cursor;
527   ignored_regions_.insert(ignored_regions_.begin() + position, region);
528 }
529
530 void RemoteClient::ignore_heap(IgnoredHeapRegion const& region)
531 {
532   if (ignored_heap_.empty()) {
533     ignored_heap_.push_back(std::move(region));
534     return;
535   }
536
537   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
538
539   size_type start = 0;
540   size_type end   = ignored_heap_.size() - 1;
541
542   // Binary search the position of insertion:
543   size_type cursor;
544   while (start <= end) {
545     cursor               = start + (end - start) / 2;
546     auto& current_region = ignored_heap_[cursor];
547     if (current_region.address == region.address)
548       return;
549     else if (current_region.address < region.address)
550       start = cursor + 1;
551     else if (cursor != 0)
552       end = cursor - 1;
553     // Avoid underflow:
554     else
555       break;
556   }
557
558   // Insert it mc_heap_ignore_region_t:
559   if (ignored_heap_[cursor].address < region.address)
560     ++cursor;
561   ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
562 }
563
564 void RemoteClient::unignore_heap(void* address, size_t size)
565 {
566   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
567
568   size_type start = 0;
569   size_type end   = ignored_heap_.size() - 1;
570
571   // Binary search:
572   size_type cursor;
573   while (start <= end) {
574     cursor       = (start + end) / 2;
575     auto& region = ignored_heap_[cursor];
576     if (region.address < address)
577       start = cursor + 1;
578     else if ((char*)region.address <= ((char*)address + size)) {
579       ignored_heap_.erase(ignored_heap_.begin() + cursor);
580       return;
581     } else if (cursor != 0)
582       end = cursor - 1;
583     // Avoid underflow:
584     else
585       break;
586   }
587 }
588
589 void RemoteClient::ignore_local_variable(const char* var_name, const char* frame_name)
590 {
591   if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
592     frame_name = nullptr;
593   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
594     info->remove_local_variable(var_name, frame_name);
595 }
596
597 std::vector<simgrid::mc::ActorInformation>& RemoteClient::actors()
598 {
599   this->refresh_simix();
600   return smx_actors_infos;
601 }
602
603 std::vector<simgrid::mc::ActorInformation>& RemoteClient::dead_actors()
604 {
605   this->refresh_simix();
606   return smx_dead_actors_infos;
607 }
608
609 void RemoteClient::dumpStack()
610 {
611   unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
612   if (as == nullptr) {
613     XBT_ERROR("Could not initialize ptrace address space");
614     return;
615   }
616
617   void* context = _UPT_create(this->pid_);
618   if (context == nullptr) {
619     unw_destroy_addr_space(as);
620     XBT_ERROR("Could not initialize ptrace context");
621     return;
622   }
623
624   unw_cursor_t cursor;
625   if (unw_init_remote(&cursor, as, context) != 0) {
626     _UPT_destroy(context);
627     unw_destroy_addr_space(as);
628     XBT_ERROR("Could not initialiez ptrace cursor");
629     return;
630   }
631
632   simgrid::mc::dumpStack(stderr, std::move(cursor));
633
634   _UPT_destroy(context);
635   unw_destroy_addr_space(as);
636 }
637
638 bool RemoteClient::actor_is_enabled(aid_t pid)
639 {
640   s_mc_message_actor_enabled_t msg{MC_MESSAGE_ACTOR_ENABLED, pid};
641   process()->getChannel().send(msg);
642   char buff[MC_MESSAGE_LENGTH];
643   ssize_t received = process()->getChannel().receive(buff, MC_MESSAGE_LENGTH, true);
644   xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
645   return ((s_mc_message_int_t*)buff)->value;
646 }
647 }
648 }