1 /* Copyright (c) 2014-2021. 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_*
23 using simgrid::mc::remote;
25 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
32 // List of library which memory segments are not considered:
33 static const std::vector<std::string> filtered_libraries = {
36 #elif defined __FreeBSD__
39 "libkvm", /* kernel data access library */
40 "libprocstat", /* process and file information retrieval */
41 "libthr", /* thread library */
44 "libargp", /* workarounds for glibc-less systems */
45 "libasan", /* gcc sanitizers */
49 "libboost_context-mt",
50 "libboost_stacktrace_addr2line",
51 "libboost_stacktrace_backtrace",
97 "libkrb5support", /*odd behaviour on fedora rawhide ... remove these when fixed*/
130 "libtsan", /* gcc sanitizers */
131 "libubsan", /* gcc sanitizers */
141 static bool is_filtered_lib(const std::string& libname)
143 return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
146 static std::string get_lib_name(const std::string& pathname)
148 std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
151 size_t pos = map_basename.rfind(".so");
152 if (pos != std::string::npos) {
153 // strip the extension (matching regex "\.so.*$")
154 libname.assign(map_basename, 0, pos);
156 // strip the version suffix (matching regex "-[.0-9-]*$")
158 pos = libname.rfind('-');
159 if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
168 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
170 auto* buffer = static_cast<char*>(buf);
171 ssize_t real_count = count;
173 ssize_t res = pread(fd, buffer, count, offset);
180 else if (errno != EINTR) {
181 perror("pread_whole");
188 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
190 const auto* buffer = static_cast<const char*>(buf);
191 ssize_t real_count = count;
193 ssize_t res = pwrite(fd, buffer, count, offset);
200 else if (errno != EINTR)
206 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
207 static const void* zero_buffer;
208 static const size_t zero_buffer_size = 10 * 4096;
210 static void zero_buffer_init()
212 int fd = open("/dev/zero", O_RDONLY);
214 xbt_die("Could not open /dev/zero");
215 zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
216 if (zero_buffer == MAP_FAILED)
217 xbt_die("Could not map the zero buffer");
221 int open_vm(pid_t pid, int flags)
223 std::string buffer = "/proc/" + std::to_string(pid) + "/mem";
224 return open(buffer.c_str(), flags);
227 // ***** RemoteSimulation
229 RemoteSimulation::RemoteSimulation(pid_t pid) : AddressSpace(this), pid_(pid), running_(true) {}
231 void RemoteSimulation::init()
233 this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
234 this->init_memory_map_info();
236 int fd = open_vm(this->pid_, O_RDWR);
237 xbt_assert(fd >= 0, "Could not open file for process virtual address space");
238 this->memory_file = fd;
240 // Read std_heap (is a struct mdesc*):
241 const simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
242 xbt_assert(std_heap_var, "No heap information in the target process");
243 xbt_assert(std_heap_var->address, "No constant address for this variable");
244 this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address));
246 this->smx_actors_infos.clear();
247 this->smx_dead_actors_infos.clear();
248 this->unw_addr_space = simgrid::mc::UnwindContext::createUnwindAddressSpace();
249 this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
250 this->unw_underlying_context = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
253 RemoteSimulation::~RemoteSimulation()
255 if (this->memory_file >= 0)
256 close(this->memory_file);
258 if (this->unw_underlying_addr_space != unw_local_addr_space) {
259 if (this->unw_underlying_addr_space)
260 unw_destroy_addr_space(this->unw_underlying_addr_space);
261 if (this->unw_underlying_context)
262 _UPT_destroy(this->unw_underlying_context);
265 unw_destroy_addr_space(this->unw_addr_space);
268 /** Refresh the information about the process
270 * Do not use directly, this is used by the getters when appropriate
271 * in order to have fresh data.
273 void RemoteSimulation::refresh_heap()
275 // Read/dereference/refresh the std_heap pointer:
277 this->heap = std::make_unique<s_xbt_mheap_t>();
278 this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address));
279 this->cache_flags_ |= RemoteSimulation::cache_heap;
282 /** Refresh the information about the process
284 * Do not use directly, this is used by the getters when appropriate
285 * in order to have fresh data.
287 void RemoteSimulation::refresh_malloc_info()
289 // Refresh process->heapinfo:
290 if (this->cache_flags_ & RemoteSimulation::cache_malloc)
292 size_t count = this->heap->heaplimit + 1;
293 if (this->heap_info.size() < count)
294 this->heap_info.resize(count);
295 this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo));
296 this->cache_flags_ |= RemoteSimulation::cache_malloc;
299 /** @brief Finds the range of the different memory segments and binary paths */
300 void RemoteSimulation::init_memory_map_info()
302 XBT_DEBUG("Get debug information ...");
303 this->maestro_stack_start_ = nullptr;
304 this->maestro_stack_end_ = nullptr;
305 this->object_infos.resize(0);
306 this->binary_info = nullptr;
308 std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
310 const char* current_name = nullptr;
312 this->object_infos.clear();
314 for (size_t i = 0; i < maps.size(); i++) {
315 simgrid::xbt::VmMap const& reg = maps[i];
316 const char* pathname = maps[i].pathname.c_str();
319 if (maps[i].pathname.empty()) {
320 current_name = nullptr;
324 // [stack], [vvar], [vsyscall], [vdso] ...
325 if (pathname[0] == '[') {
326 if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
327 this->maestro_stack_start_ = remote(reg.start_addr);
328 this->maestro_stack_end_ = remote(reg.end_addr);
330 current_name = nullptr;
334 if (current_name && strcmp(current_name, pathname) == 0)
337 current_name = pathname;
338 if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
341 const bool is_executable = not i;
343 if (not is_executable) {
344 libname = get_lib_name(pathname);
345 if (is_filtered_lib(libname)) {
350 std::shared_ptr<simgrid::mc::ObjectInformation> info =
351 simgrid::mc::createObjectInformation(this->memory_map_, pathname);
352 this->object_infos.push_back(info);
354 this->binary_info = info;
357 // Resolve time (including across different objects):
358 for (auto const& object_info : this->object_infos)
359 postProcessObjectInformation(this, object_info.get());
361 xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
362 xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
364 XBT_DEBUG("Get debug information done !");
367 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteSimulation::find_object_info(RemotePtr<void> addr) const
369 for (auto const& object_info : this->object_infos)
370 if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
375 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_exec(RemotePtr<void> addr) const
377 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
378 if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
383 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_rw(RemotePtr<void> addr) const
385 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
386 if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
391 simgrid::mc::Frame* RemoteSimulation::find_function(RemotePtr<void> ip) const
393 std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
394 return info ? info->find_function((void*)ip.address()) : nullptr;
397 /** Find (one occurrence of) the named variable definition
399 const simgrid::mc::Variable* RemoteSimulation::find_variable(const char* name) const
401 // First lookup the variable in the executable shared object.
402 // A global variable used directly by the executable code from a library
403 // is reinstantiated in the executable memory .data/.bss.
404 // We need to look up the variable in the executable first.
405 if (this->binary_info) {
406 std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
407 const simgrid::mc::Variable* var = info->find_variable(name);
412 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
413 const simgrid::mc::Variable* var = info->find_variable(name);
421 void RemoteSimulation::read_variable(const char* name, void* target, size_t size) const
423 const simgrid::mc::Variable* var = this->find_variable(name);
424 xbt_assert(var, "Variable %s not found", name);
425 xbt_assert(var->address, "No simple location for this variable");
426 xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
427 xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
428 size, (size_t)var->type->full_type->byte_size);
429 this->read_bytes(target, size, remote(var->address));
432 std::string RemoteSimulation::read_string(RemotePtr<char> address) const
437 std::vector<char> res(128);
441 ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
442 if (c == -1 && errno == EINTR)
444 xbt_assert(c > 0, "Could not read string from remote process");
446 const void* p = memchr(res.data() + off, '\0', c);
448 return std::string(res.data());
451 if (off == (off_t)res.size())
452 res.resize(res.size() * 2);
456 void* RemoteSimulation::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address,
457 ReadOptions /*options*/) const
459 if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
460 xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
464 /** Write data to a process memory
466 * @param buffer local memory address (source)
467 * @param len data size
468 * @param address target process memory address (target)
470 void RemoteSimulation::write_bytes(const void* buffer, size_t len, RemotePtr<void> address) const
472 if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
473 xbt_die("Write to process %lli failed", (long long)this->pid_);
476 void RemoteSimulation::clear_bytes(RemotePtr<void> address, size_t len) const
478 pthread_once(&zero_buffer_flag, zero_buffer_init);
480 size_t s = len > zero_buffer_size ? zero_buffer_size : len;
481 this->write_bytes(zero_buffer, s, address);
482 address = remote((char*)address.address() + s);
487 void RemoteSimulation::ignore_region(std::uint64_t addr, std::size_t size)
489 IgnoredRegion region;
493 auto pos = std::lower_bound(ignored_regions_.begin(), ignored_regions_.end(), region,
494 [](auto const& reg1, auto const& reg2) {
495 return reg1.addr < reg2.addr || (reg1.addr == reg2.addr && reg1.size < reg2.size);
497 if (pos == ignored_regions_.end() || pos->addr != addr || pos->size != size)
498 ignored_regions_.insert(pos, region);
501 void RemoteSimulation::ignore_heap(IgnoredHeapRegion const& region)
503 // Binary search the position of insertion:
504 auto pos = std::lower_bound(ignored_heap_.begin(), ignored_heap_.end(), region.address,
505 [](auto const& reg, auto const* addr) { return reg.address < addr; });
506 if (pos == ignored_heap_.end() || pos->address != region.address) {
508 ignored_heap_.insert(pos, region);
512 void RemoteSimulation::unignore_heap(void* address, size_t size)
515 auto pos = std::lower_bound(ignored_heap_.begin(), ignored_heap_.end(), address,
516 [](auto const& reg, auto const* addr) { return reg.address < addr; });
517 if (pos != ignored_heap_.end() && static_cast<char*>(pos->address) <= static_cast<char*>(address) + size)
518 ignored_heap_.erase(pos);
521 void RemoteSimulation::ignore_local_variable(const char* var_name, const char* frame_name) const
523 if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
524 frame_name = nullptr;
525 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
526 info->remove_local_variable(var_name, frame_name);
529 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::actors()
531 this->refresh_simix();
532 return smx_actors_infos;
535 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::dead_actors()
537 this->refresh_simix();
538 return smx_dead_actors_infos;
541 void RemoteSimulation::dump_stack() const
543 unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
545 XBT_ERROR("Could not initialize ptrace address space");
549 void* context = _UPT_create(this->pid_);
550 if (context == nullptr) {
551 unw_destroy_addr_space(as);
552 XBT_ERROR("Could not initialize ptrace context");
557 if (unw_init_remote(&cursor, as, context) != 0) {
558 _UPT_destroy(context);
559 unw_destroy_addr_space(as);
560 XBT_ERROR("Could not initialiez ptrace cursor");
564 simgrid::mc::dumpStack(stderr, &cursor);
566 _UPT_destroy(context);
567 unw_destroy_addr_space(as);
570 } // namespace simgrid