1 /* Copyright (c) 2014-2020. The SimGrid Team. All rights reserved. */
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. */
6 #define _FILE_OFFSET_BITS 64 /* needed for pread_whole to work as expected on 32bits */
8 #include "src/mc/remote/RemoteSimulation.hpp"
10 #include "src/mc/mc_smx.hpp"
11 #include "src/mc/sosp/Snapshot.hpp"
12 #include "xbt/file.hpp"
16 #include <libunwind-ptrace.h>
17 #include <sys/mman.h> // PROT_*
21 using simgrid::mc::remote;
23 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
30 // List of library which memory segments are not considered:
31 static const std::vector<std::string> filtered_libraries = {
34 #elif defined __FreeBSD__
37 "libkvm", /* kernel data access library */
38 "libprocstat", /* process and file information retrieval */
39 "libthr", /* thread library */
42 "libargp", /* workarounds for glibc-less systems */
43 "libasan", /* gcc sanitizers */
46 "libboost_context-mt",
47 "libboost_stacktrace_addr2line",
48 "libboost_stacktrace_backtrace",
82 "libkrb5support", /*odd behaviour on fedora rawhide ... remove these when fixed*/
107 "libtsan", /* gcc sanitizers */
108 "libubsan", /* gcc sanitizers */
117 static bool is_simgrid_lib(const std::string& libname)
119 return libname == "libsimgrid";
122 static bool is_filtered_lib(const std::string& libname)
124 return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
127 static std::string get_lib_name(const std::string& pathname)
129 std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
132 size_t pos = map_basename.rfind(".so");
133 if (pos != std::string::npos) {
134 // strip the extension (matching regex "\.so.*$")
135 libname.assign(map_basename, 0, pos);
137 // strip the version suffix (matching regex "-[.0-9-]*$")
139 pos = libname.rfind('-');
140 if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
149 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
151 auto* buffer = static_cast<char*>(buf);
152 ssize_t real_count = count;
154 ssize_t res = pread(fd, buffer, count, offset);
161 else if (errno != EINTR) {
162 perror("pread_whole");
169 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
171 const auto* buffer = static_cast<const char*>(buf);
172 ssize_t real_count = count;
174 ssize_t res = pwrite(fd, buffer, count, offset);
181 else if (errno != EINTR)
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;
191 static void zero_buffer_init()
193 int fd = open("/dev/zero", O_RDONLY);
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");
202 int open_vm(pid_t pid, int flags)
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;
211 return open(buffer, flags);
214 // ***** RemoteSimulation
216 RemoteSimulation::RemoteSimulation(pid_t pid) : AddressSpace(this), pid_(pid), running_(true) {}
218 void RemoteSimulation::init()
220 this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
221 this->init_memory_map_info();
223 int fd = open_vm(this->pid_, O_RDWR);
224 xbt_assert(fd >= 0, "Could not open file for process virtual address space");
225 this->memory_file = fd;
227 // Read std_heap (is a struct mdesc*):
228 const simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
229 xbt_assert(std_heap_var, "No heap information in the target process");
230 xbt_assert(std_heap_var->address, "No constant address for this variable");
231 this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address));
233 this->smx_actors_infos.clear();
234 this->smx_dead_actors_infos.clear();
235 this->unw_addr_space = simgrid::mc::UnwindContext::createUnwindAddressSpace();
236 this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
237 this->unw_underlying_context = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
240 RemoteSimulation::~RemoteSimulation()
242 if (this->memory_file >= 0)
243 close(this->memory_file);
245 if (this->unw_underlying_addr_space != unw_local_addr_space) {
246 if (this->unw_underlying_addr_space)
247 unw_destroy_addr_space(this->unw_underlying_addr_space);
248 if (this->unw_underlying_context)
249 _UPT_destroy(this->unw_underlying_context);
252 unw_destroy_addr_space(this->unw_addr_space);
255 /** Refresh the information about the process
257 * Do not use directly, this is used by the getters when appropriate
258 * in order to have fresh data.
260 void RemoteSimulation::refresh_heap()
262 // Read/dereference/refresh the std_heap pointer:
264 this->heap = std::make_unique<s_xbt_mheap_t>();
265 this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address));
266 this->cache_flags_ |= RemoteSimulation::cache_heap;
269 /** Refresh the information about the process
271 * Do not use directly, this is used by the getters when appropriate
272 * in order to have fresh data.
274 void RemoteSimulation::refresh_malloc_info()
276 // Refresh process->heapinfo:
277 if (this->cache_flags_ & RemoteSimulation::cache_malloc)
279 size_t count = this->heap->heaplimit + 1;
280 if (this->heap_info.size() < count)
281 this->heap_info.resize(count);
282 this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo));
283 this->cache_flags_ |= RemoteSimulation::cache_malloc;
286 /** @brief Finds the range of the different memory segments and binary paths */
287 void RemoteSimulation::init_memory_map_info()
289 XBT_DEBUG("Get debug information ...");
290 this->maestro_stack_start_ = nullptr;
291 this->maestro_stack_end_ = nullptr;
292 this->object_infos.resize(0);
293 this->binary_info = nullptr;
294 this->libsimgrid_info = nullptr;
296 std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
298 const char* current_name = nullptr;
300 this->object_infos.clear();
302 for (size_t i = 0; i < maps.size(); i++) {
303 simgrid::xbt::VmMap const& reg = maps[i];
304 const char* pathname = maps[i].pathname.c_str();
307 if (maps[i].pathname.empty()) {
308 current_name = nullptr;
312 // [stack], [vvar], [vsyscall], [vdso] ...
313 if (pathname[0] == '[') {
314 if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
315 this->maestro_stack_start_ = remote(reg.start_addr);
316 this->maestro_stack_end_ = remote(reg.end_addr);
318 current_name = nullptr;
322 if (current_name && strcmp(current_name, pathname) == 0)
325 current_name = pathname;
326 if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
329 const bool is_executable = not i;
331 if (not is_executable) {
332 libname = get_lib_name(pathname);
333 if (is_filtered_lib(libname)) {
338 std::shared_ptr<simgrid::mc::ObjectInformation> info =
339 simgrid::mc::createObjectInformation(this->memory_map_, pathname);
340 this->object_infos.push_back(info);
342 this->binary_info = info;
343 else if (is_simgrid_lib(libname))
344 this->libsimgrid_info = info;
347 // Resolve time (including across different objects):
348 for (auto const& object_info : this->object_infos)
349 postProcessObjectInformation(this, object_info.get());
351 xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
352 xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
354 XBT_DEBUG("Get debug information done !");
357 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteSimulation::find_object_info(RemotePtr<void> addr) const
359 for (auto const& object_info : this->object_infos)
360 if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
365 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_exec(RemotePtr<void> addr) const
367 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
368 if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
373 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_rw(RemotePtr<void> addr) const
375 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
376 if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
381 simgrid::mc::Frame* RemoteSimulation::find_function(RemotePtr<void> ip) const
383 std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
384 return info ? info->find_function((void*)ip.address()) : nullptr;
387 /** Find (one occurrence of) the named variable definition
389 const simgrid::mc::Variable* RemoteSimulation::find_variable(const char* name) const
391 // First lookup the variable in the executable shared object.
392 // A global variable used directly by the executable code from a library
393 // is reinstantiated in the executable memory .data/.bss.
394 // We need to look up the variable in the executable first.
395 if (this->binary_info) {
396 std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
397 const simgrid::mc::Variable* var = info->find_variable(name);
402 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
403 const simgrid::mc::Variable* var = info->find_variable(name);
411 void RemoteSimulation::read_variable(const char* name, void* target, size_t size) const
413 const simgrid::mc::Variable* var = this->find_variable(name);
414 xbt_assert(var, "Variable %s not found", name);
415 xbt_assert(var->address, "No simple location for this variable");
416 xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
417 xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
418 size, (size_t)var->type->full_type->byte_size);
419 this->read_bytes(target, size, remote(var->address));
422 std::string RemoteSimulation::read_string(RemotePtr<char> address) const
427 std::vector<char> res(128);
431 ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
432 if (c == -1 && errno == EINTR)
434 xbt_assert(c > 0, "Could not read string from remote process");
436 const void* p = memchr(res.data() + off, '\0', c);
438 return std::string(res.data());
441 if (off == (off_t)res.size())
442 res.resize(res.size() * 2);
446 void* RemoteSimulation::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address,
447 ReadOptions /*options*/) const
449 if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
450 xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
454 /** Write data to a process memory
456 * @param buffer local memory address (source)
457 * @param len data size
458 * @param address target process memory address (target)
460 void RemoteSimulation::write_bytes(const void* buffer, size_t len, RemotePtr<void> address) const
462 if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
463 xbt_die("Write to process %lli failed", (long long)this->pid_);
466 void RemoteSimulation::clear_bytes(RemotePtr<void> address, size_t len) const
468 pthread_once(&zero_buffer_flag, zero_buffer_init);
470 size_t s = len > zero_buffer_size ? zero_buffer_size : len;
471 this->write_bytes(zero_buffer, s, address);
472 address = remote((char*)address.address() + s);
477 void RemoteSimulation::ignore_region(std::uint64_t addr, std::size_t size)
479 IgnoredRegion region;
483 if (ignored_regions_.empty()) {
484 ignored_regions_.push_back(region);
488 unsigned int cursor = 0;
489 const IgnoredRegion* current_region = nullptr;
492 int end = ignored_regions_.size() - 1;
493 while (start <= end) {
494 cursor = (start + end) / 2;
495 current_region = &ignored_regions_[cursor];
496 if (current_region->addr == addr) {
497 if (current_region->size == size)
499 else if (current_region->size < size)
503 } else if (current_region->addr < addr)
509 std::size_t position;
510 if (current_region->addr == addr) {
511 if (current_region->size < size)
512 position = cursor + 1;
515 } else if (current_region->addr < addr)
516 position = cursor + 1;
519 ignored_regions_.insert(ignored_regions_.begin() + position, region);
522 void RemoteSimulation::ignore_heap(IgnoredHeapRegion const& region)
524 if (ignored_heap_.empty()) {
525 ignored_heap_.push_back(std::move(region));
529 typedef std::vector<IgnoredHeapRegion>::size_type size_type;
532 size_type end = ignored_heap_.size() - 1;
534 // Binary search the position of insertion:
536 while (start <= end) {
537 cursor = start + (end - start) / 2;
538 auto const& current_region = ignored_heap_[cursor];
539 if (current_region.address == region.address)
541 else if (current_region.address < region.address)
543 else if (cursor != 0)
550 // Insert it mc_heap_ignore_region_t:
551 if (ignored_heap_[cursor].address < region.address)
553 ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
556 void RemoteSimulation::unignore_heap(void* address, size_t size)
558 typedef std::vector<IgnoredHeapRegion>::size_type size_type;
561 size_type end = ignored_heap_.size() - 1;
565 while (start <= end) {
566 cursor = (start + end) / 2;
567 auto const& region = ignored_heap_[cursor];
568 if (region.address < address)
570 else if ((char*)region.address <= ((char*)address + size)) {
571 ignored_heap_.erase(ignored_heap_.begin() + cursor);
573 } else if (cursor != 0)
581 void RemoteSimulation::ignore_local_variable(const char* var_name, const char* frame_name) const
583 if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
584 frame_name = nullptr;
585 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
586 info->remove_local_variable(var_name, frame_name);
589 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::actors()
591 this->refresh_simix();
592 return smx_actors_infos;
595 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::dead_actors()
597 this->refresh_simix();
598 return smx_dead_actors_infos;
601 void RemoteSimulation::dump_stack() const
603 unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
605 XBT_ERROR("Could not initialize ptrace address space");
609 void* context = _UPT_create(this->pid_);
610 if (context == nullptr) {
611 unw_destroy_addr_space(as);
612 XBT_ERROR("Could not initialize ptrace context");
617 if (unw_init_remote(&cursor, as, context) != 0) {
618 _UPT_destroy(context);
619 unw_destroy_addr_space(as);
620 XBT_ERROR("Could not initialiez ptrace cursor");
624 simgrid::mc::dumpStack(stderr, &cursor);
626 _UPT_destroy(context);
627 unw_destroy_addr_space(as);
630 } // namespace simgrid