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 <algorithm>
   9 #include <cassert>
  10 #include <cerrno>
  11 #include <cstddef>
  12 #include <cstdint>
  13 #include <string>
  14 #include <vector>
  15
  16 #include <sys/ptrace.h>
  17
  18 #include <cstdio>
  19
  20 #include <fcntl.h>
  21 #include <sys/mman.h> // PROT_*
  22 #include <sys/types.h>
  23 #include <unistd.h>
  24
  25 #include <pthread.h>
  26
  27 #include <libgen.h>
  28
  29 #include <libunwind-ptrace.h>
  30 #include <libunwind.h>
  31
  32 #include "xbt/base.h"
  33 #include "xbt/file.hpp"
  34 #include "xbt/log.h"
  35 #include <xbt/mmalloc.h>
  36
  37 #include "src/mc/mc_smx.hpp"
  38 #include "src/mc/mc_unw.hpp"
  39 #include "src/mc/sosp/mc_snapshot.hpp"
  40
  41 #include "src/mc/AddressSpace.hpp"
  42 #include "src/mc/ObjectInformation.hpp"
  43 #include "src/mc/Variable.hpp"
  44 #include "src/mc/remote/RemoteClient.hpp"
  45
  46 using simgrid::mc::remote;
  47
  48 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
  49
  50 namespace simgrid {
  51 namespace mc {
  52
  53 // ***** Helper stuff
  54
  55 // List of library which memory segments are not considered:
  56 static const std::vector<std::string> filtered_libraries = {
  57 #ifdef __linux__
  58     "ld",
  59 #elif defined __FreeBSD__
  60     "ld-elf",
  61     "ld-elf32",
  62     "libkvm",      /* kernel data access library */
  63     "libprocstat", /* process and file information retrieval */
  64     "libthr",      /* thread library */
  65     "libutil",
  66 #endif
  67     "libargp", /* workarounds for glibc-less systems */
  68     "libasan", /* gcc sanitizers */
  69     "libboost_chrono",
  70     "libboost_context",
  71     "libboost_context-mt",
  72     "libboost_stacktrace_backtrace",
  73     "libboost_system",
  74     "libboost_thread",
  75     "libboost_timer",
  76     "libboost_unit_test_framework",
  77     "libbz2",
  78     "libc",
  79     "libc++",
  80     "libcdt",
  81     "libcgraph",
  82     "libcrypto",
  83     "libcxxrt",
  84     "libdl",
  85     "libdw",
  86     "libelf",
  87     "libevent",
  88     "libexecinfo",
  89     "libflang",
  90     "libflangrti",
  91     "libgcc_s",
  92     "libgfortran",
  93     "libimf",
  94     "libintlc",
  95     "libirng",
  96     "liblua5.1",
  97     "liblua5.3",
  98     "liblzma",
  99     "libm",
 100     "libomp",
 101     "libpapi",
 102     "libpfm",
 103     "libpgmath",
 104     "libpthread",
 105     "libquadmath",
 106     "librt",
 107     "libstdc++",
 108     "libsvml",
 109     "libtsan",  /* gcc sanitizers */
 110     "libubsan", /* gcc sanitizers */
 111     "libunwind",
 112     "libunwind-ptrace",
 113     "libunwind-x86",
 114     "libunwind-x86_64",
 115     "libz"};
 116
 117 static bool is_simgrid_lib(const std::string& libname)
 118 {
 119   return libname == "libsimgrid";
 120 }
 121
 122 static bool is_filtered_lib(const std::string& libname)
 123 {
 124   return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
 125 }
 126
 127 static std::string get_lib_name(const std::string& pathname)
 128 {
 129   std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
 130   std::string libname;
 131
 132   size_t pos = map_basename.rfind(".so");
 133   if (pos != std::string::npos) {
 134     // strip the extension (matching regex "\.so.*$")
 135     libname.assign(map_basename, 0, pos);
 136
 137     // strip the version suffix (matching regex "-[.0-9-]*$")
 138     while (true) {
 139       pos = libname.rfind('-');
 140       if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
 141         break;
 142       libname.erase(pos);
 143     }
 144   }
 145
 146   return libname;
 147 }
 148
 149 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
 150 {
 151   char* buffer       = (char*)buf;
 152   ssize_t real_count = count;
 153   while (count) {
 154     ssize_t res = pread(fd, buffer, count, offset);
 155     if (res > 0) {
 156       count -= res;
 157       buffer += res;
 158       offset += res;
 159     } else if (res == 0)
 160       return -1;
 161     else if (errno != EINTR) {
 162       perror("pread_whole");
 163       return -1;
 164     }
 165   }
 166   return real_count;
 167 }
 168
 169 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
 170 {
 171   const char* buffer = (const char*)buf;
 172   ssize_t real_count = count;
 173   while (count) {
 174     ssize_t res = pwrite(fd, buffer, count, offset);
 175     if (res > 0) {
 176       count -= res;
 177       buffer += res;
 178       offset += res;
 179     } else if (res == 0)
 180       return -1;
 181     else if (errno != EINTR)
 182       return -1;
 183   }
 184   return real_count;
 185 }
 186
 187 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
 188 static const void* zero_buffer;
 189 static const size_t zero_buffer_size = 10 * 4096;
 190
 191 static void zero_buffer_init()
 192 {
 193   int fd = open("/dev/zero", O_RDONLY);
 194   if (fd < 0)
 195     xbt_die("Could not open /dev/zero");
 196   zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
 197   if (zero_buffer == MAP_FAILED)
 198     xbt_die("Could not map the zero buffer");
 199   close(fd);
 200 }
 201
 202 int open_vm(pid_t pid, int flags)
 203 {
 204   const size_t buffer_size = 30;
 205   char buffer[buffer_size];
 206   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long)pid);
 207   if (res < 0 || (size_t)res >= buffer_size) {
 208     errno = ENAMETOOLONG;
 209     return -1;
 210   }
 211   return open(buffer, flags);
 212 }
 213
 214 // ***** Process
 215
 216 RemoteClient::RemoteClient(pid_t pid, int sockfd) : AddressSpace(this), pid_(pid), channel_(sockfd), running_(true)
 217 {
 218 }
 219
 220 void RemoteClient::init()
 221 {
 222   this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
 223   this->init_memory_map_info();
 224
 225   int fd = open_vm(this->pid_, O_RDWR);
 226   if (fd < 0)
 227     xbt_die("Could not open file for process virtual address space");
 228   this->memory_file = fd;
 229
 230   // Read std_heap (is a struct mdesc*):
 231   simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
 232   if (not std_heap_var)
 233     xbt_die("No heap information in the target process");
 234   if (not std_heap_var->address)
 235     xbt_die("No constant address for this variable");
 236   this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address),
 237                    simgrid::mc::ProcessIndexDisabled);
 238
 239   this->smx_actors_infos.clear();
 240   this->smx_dead_actors_infos.clear();
 241   this->unw_addr_space            = simgrid::mc::UnwindContext::createUnwindAddressSpace();
 242   this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
 243   this->unw_underlying_context    = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
 244 }
 245
 246 RemoteClient::~RemoteClient()
 247 {
 248   if (this->memory_file >= 0)
 249     close(this->memory_file);
 250
 251   if (this->unw_underlying_addr_space != unw_local_addr_space) {
 252     if (this->unw_underlying_addr_space)
 253       unw_destroy_addr_space(this->unw_underlying_addr_space);
 254     if (this->unw_underlying_context)
 255       _UPT_destroy(this->unw_underlying_context);
 256   }
 257
 258   unw_destroy_addr_space(this->unw_addr_space);
 259 }
 260
 261 /** Refresh the information about the process
 262  *
 263  *  Do not use directly, this is used by the getters when appropriate
 264  *  in order to have fresh data.
 265  */
 266 void RemoteClient::refresh_heap()
 267 {
 268   // Read/dereference/refresh the std_heap pointer:
 269   if (not this->heap)
 270     this->heap = std::unique_ptr<s_xbt_mheap_t>(new s_xbt_mheap_t());
 271   this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address), simgrid::mc::ProcessIndexDisabled);
 272   this->cache_flags_ |= RemoteClient::cache_heap;
 273 }
 274
 275 /** Refresh the information about the process
 276  *
 277  *  Do not use direclty, this is used by the getters when appropriate
 278  *  in order to have fresh data.
 279  * */
 280 void RemoteClient::refresh_malloc_info()
 281 {
 282   // Refresh process->heapinfo:
 283   if (this->cache_flags_ & RemoteClient::cache_malloc)
 284     return;
 285   size_t count = this->heap->heaplimit + 1;
 286   if (this->heap_info.size() < count)
 287     this->heap_info.resize(count);
 288   this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo),
 289                    simgrid::mc::ProcessIndexDisabled);
 290   this->cache_flags_ |= RemoteClient::cache_malloc;
 291 }
 292
 293 /** @brief Finds the range of the different memory segments and binary paths */
 294 void RemoteClient::init_memory_map_info()
 295 {
 296   XBT_DEBUG("Get debug information ...");
 297   this->maestro_stack_start_ = nullptr;
 298   this->maestro_stack_end_   = nullptr;
 299   this->object_infos.resize(0);
 300   this->binary_info     = nullptr;
 301   this->libsimgrid_info = nullptr;
 302
 303   std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
 304
 305   const char* current_name = nullptr;
 306
 307   this->object_infos.clear();
 308
 309   for (size_t i = 0; i < maps.size(); i++) {
 310     simgrid::xbt::VmMap const& reg = maps[i];
 311     const char* pathname           = maps[i].pathname.c_str();
 312
 313     // Nothing to do
 314     if (maps[i].pathname.empty()) {
 315       current_name = nullptr;
 316       continue;
 317     }
 318
 319     // [stack], [vvar], [vsyscall], [vdso] ...
 320     if (pathname[0] == '[') {
 321       if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
 322         this->maestro_stack_start_ = remote(reg.start_addr);
 323         this->maestro_stack_end_   = remote(reg.end_addr);
 324       }
 325       current_name = nullptr;
 326       continue;
 327     }
 328
 329     if (current_name && strcmp(current_name, pathname) == 0)
 330       continue;
 331
 332     current_name = pathname;
 333     if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
 334       continue;
 335
 336     const bool is_executable = not i;
 337     std::string libname;
 338     if (not is_executable) {
 339       libname = get_lib_name(pathname);
 340       if (is_filtered_lib(libname)) {
 341         continue;
 342       }
 343     }
 344
 345     std::shared_ptr<simgrid::mc::ObjectInformation> info =
 346         simgrid::mc::createObjectInformation(this->memory_map_, pathname);
 347     this->object_infos.push_back(info);
 348     if (is_executable)
 349       this->binary_info = info;
 350     else if (is_simgrid_lib(libname))
 351       this->libsimgrid_info = info;
 352   }
 353
 354   // Resolve time (including across different objects):
 355   for (auto const& object_info : this->object_infos)
 356     postProcessObjectInformation(this, object_info.get());
 357
 358   xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
 359   xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
 360
 361   XBT_DEBUG("Get debug information done !");
 362 }
 363
 364 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteClient::find_object_info(RemotePtr<void> addr) const
 365 {
 366   for (auto const& object_info : this->object_infos)
 367     if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
 368       return object_info;
 369   return nullptr;
 370 }
 371
 372 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_exec(RemotePtr<void> addr) const
 373 {
 374   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
 375     if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
 376       return info;
 377   return nullptr;
 378 }
 379
 380 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_rw(RemotePtr<void> addr) const
 381 {
 382   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
 383     if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
 384       return info;
 385   return nullptr;
 386 }
 387
 388 simgrid::mc::Frame* RemoteClient::find_function(RemotePtr<void> ip) const
 389 {
 390   std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
 391   return info ? info->find_function((void*)ip.address()) : nullptr;
 392 }
 393
 394 /** Find (one occurrence of) the named variable definition
 395  */
 396 simgrid::mc::Variable* RemoteClient::find_variable(const char* name) const
 397 {
 398   // First lookup the variable in the executable shared object.
 399   // A global variable used directly by the executable code from a library
 400   // is reinstanciated in the executable memory .data/.bss.
 401   // We need to look up the variable in the executable first.
 402   if (this->binary_info) {
 403     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
 404     simgrid::mc::Variable* var                                  = info->find_variable(name);
 405     if (var)
 406       return var;
 407   }
 408
 409   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
 410     simgrid::mc::Variable* var = info->find_variable(name);
 411     if (var)
 412       return var;
 413   }
 414
 415   return nullptr;
 416 }
 417
 418 void RemoteClient::read_variable(const char* name, void* target, size_t size) const
 419 {
 420   simgrid::mc::Variable* var = this->find_variable(name);
 421   xbt_assert(var->address, "No simple location for this variable");
 422   xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
 423   xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
 424              size, (size_t)var->type->full_type->byte_size);
 425   this->read_bytes(target, size, remote(var->address));
 426 }
 427
 428 std::string RemoteClient::read_string(RemotePtr<char> address) const
 429 {
 430   if (not address)
 431     return {};
 432
 433   std::vector<char> res(128);
 434   off_t off = 0;
 435
 436   while (1) {
 437     ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
 438     if (c == -1) {
 439       if (errno == EINTR)
 440         continue;
 441       else
 442         xbt_die("Could not read from from remote process");
 443     }
 444     if (c == 0)
 445       xbt_die("Could not read string from remote process");
 446
 447     void* p = memchr(res.data() + off, '\0', c);
 448     if (p)
 449       return std::string(res.data());
 450
 451     off += c;
 452     if (off == (off_t)res.size())
 453       res.resize(res.size() * 2);
 454   }
 455 }
 456
 457 const void* RemoteClient::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address, int process_index,
 458                                      ReadOptions options) const
 459 {
 460 #if HAVE_SMPI
 461   if (process_index != simgrid::mc::ProcessIndexDisabled) {
 462     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->find_object_info_rw(address);
 463     // Segment overlap is not handled.
 464     if (info.get() && this->privatized(*info)) {
 465       if (process_index < 0)
 466         xbt_die("Missing process index");
 467       if (process_index >= (int)MC_smpi_process_count())
 468         xbt_die("Invalid process index");
 469
 470       // Read smpi_privatization_regions from MCed:
 471       smpi_privatization_region_t remote_smpi_privatization_regions =
 472           mc_model_checker->process().read_variable<smpi_privatization_region_t>("smpi_privatization_regions");
 473
 474       s_smpi_privatization_region_t privatization_region =
 475           mc_model_checker->process().read<s_smpi_privatization_region_t>(
 476               remote(remote_smpi_privatization_regions + process_index));
 477
 478       // Address translation in the privatization segment:
 479       size_t offset = address.address() - (std::uint64_t)info->start_rw;
 480       address       = remote((char*)privatization_region.address + offset);
 481     }
 482   }
 483 #endif
 484   if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
 485     xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
 486   return buffer;
 487 }
 488
 489 /** Write data to a process memory
 490  *
 491  *  @param buffer   local memory address (source)
 492  *  @param len      data size
 493  *  @param address  target process memory address (target)
 494  */
 495 void RemoteClient::write_bytes(const void* buffer, size_t len, RemotePtr<void> address)
 496 {
 497   if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
 498     xbt_die("Write to process %lli failed", (long long)this->pid_);
 499 }
 500
 501 void RemoteClient::clear_bytes(RemotePtr<void> address, size_t len)
 502 {
 503   pthread_once(&zero_buffer_flag, zero_buffer_init);
 504   while (len) {
 505     size_t s = len > zero_buffer_size ? zero_buffer_size : len;
 506     this->write_bytes(zero_buffer, s, address);
 507     address = remote((char*)address.address() + s);
 508     len -= s;
 509   }
 510 }
 511
 512 void RemoteClient::ignore_region(std::uint64_t addr, std::size_t size)
 513 {
 514   IgnoredRegion region;
 515   region.addr = addr;
 516   region.size = size;
 517
 518   if (ignored_regions_.empty()) {
 519     ignored_regions_.push_back(region);
 520     return;
 521   }
 522
 523   unsigned int cursor           = 0;
 524   IgnoredRegion* current_region = nullptr;
 525
 526   int start = 0;
 527   int end   = ignored_regions_.size() - 1;
 528   while (start <= end) {
 529     cursor         = (start + end) / 2;
 530     current_region = &ignored_regions_[cursor];
 531     if (current_region->addr == addr) {
 532       if (current_region->size == size)
 533         return;
 534       else if (current_region->size < size)
 535         start = cursor + 1;
 536       else
 537         end = cursor - 1;
 538     } else if (current_region->addr < addr)
 539       start = cursor + 1;
 540     else
 541       end = cursor - 1;
 542   }
 543
 544   std::size_t position;
 545   if (current_region->addr == addr) {
 546     if (current_region->size < size)
 547       position = cursor + 1;
 548     else
 549       position = cursor;
 550   } else if (current_region->addr < addr)
 551     position = cursor + 1;
 552   else
 553     position = cursor;
 554   ignored_regions_.insert(ignored_regions_.begin() + position, region);
 555 }
 556
 557 void RemoteClient::ignore_heap(IgnoredHeapRegion const& region)
 558 {
 559   if (ignored_heap_.empty()) {
 560     ignored_heap_.push_back(std::move(region));
 561     return;
 562   }
 563
 564   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
 565
 566   size_type start = 0;
 567   size_type end   = ignored_heap_.size() - 1;
 568
 569   // Binary search the position of insertion:
 570   size_type cursor;
 571   while (start <= end) {
 572     cursor               = start + (end - start) / 2;
 573     auto& current_region = ignored_heap_[cursor];
 574     if (current_region.address == region.address)
 575       return;
 576     else if (current_region.address < region.address)
 577       start = cursor + 1;
 578     else if (cursor != 0)
 579       end = cursor - 1;
 580     // Avoid underflow:
 581     else
 582       break;
 583   }
 584
 585   // Insert it mc_heap_ignore_region_t:
 586   if (ignored_heap_[cursor].address < region.address)
 587     ++cursor;
 588   ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
 589 }
 590
 591 void RemoteClient::unignore_heap(void* address, size_t size)
 592 {
 593   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
 594
 595   size_type start = 0;
 596   size_type end   = ignored_heap_.size() - 1;
 597
 598   // Binary search:
 599   size_type cursor;
 600   while (start <= end) {
 601     cursor       = (start + end) / 2;
 602     auto& region = ignored_heap_[cursor];
 603     if (region.address < address)
 604       start = cursor + 1;
 605     else if ((char*)region.address <= ((char*)address + size)) {
 606       ignored_heap_.erase(ignored_heap_.begin() + cursor);
 607       return;
 608     } else if (cursor != 0)
 609       end = cursor - 1;
 610     // Avoid underflow:
 611     else
 612       break;
 613   }
 614 }
 615
 616 void RemoteClient::ignore_local_variable(const char* var_name, const char* frame_name)
 617 {
 618   if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
 619     frame_name = nullptr;
 620   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
 621     info->remove_local_variable(var_name, frame_name);
 622 }
 623
 624 std::vector<simgrid::mc::ActorInformation>& RemoteClient::actors()
 625 {
 626   this->refresh_simix();
 627   return smx_actors_infos;
 628 }
 629
 630 std::vector<simgrid::mc::ActorInformation>& RemoteClient::dead_actors()
 631 {
 632   this->refresh_simix();
 633   return smx_dead_actors_infos;
 634 }
 635
 636 void RemoteClient::dumpStack()
 637 {
 638   unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
 639   if (as == nullptr) {
 640     XBT_ERROR("Could not initialize ptrace address space");
 641     return;
 642   }
 643
 644   void* context = _UPT_create(this->pid_);
 645   if (context == nullptr) {
 646     unw_destroy_addr_space(as);
 647     XBT_ERROR("Could not initialize ptrace context");
 648     return;
 649   }
 650
 651   unw_cursor_t cursor;
 652   if (unw_init_remote(&cursor, as, context) != 0) {
 653     _UPT_destroy(context);
 654     unw_destroy_addr_space(as);
 655     XBT_ERROR("Could not initialiez ptrace cursor");
 656     return;
 657   }
 658
 659   simgrid::mc::dumpStack(stderr, cursor);
 660
 661   _UPT_destroy(context);
 662   unw_destroy_addr_space(as);
 663 }
 664
 665 bool RemoteClient::actor_is_enabled(aid_t pid)
 666 {
 667   s_mc_message_actor_enabled_t msg{MC_MESSAGE_ACTOR_ENABLED, pid};
 668   process()->getChannel().send(msg);
 669   char buff[MC_MESSAGE_LENGTH];
 670   ssize_t received = process()->getChannel().receive(buff, MC_MESSAGE_LENGTH, true);
 671   xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
 672   return ((s_mc_message_int_t*)buff)->value;
 673 }
 674 }
 675 }