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/RemoteClient.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_*
19 using simgrid::mc::remote;
21 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
28 // List of library which memory segments are not considered:
29 static const std::vector<std::string> filtered_libraries = {
32 #elif defined __FreeBSD__
35 "libkvm", /* kernel data access library */
36 "libprocstat", /* process and file information retrieval */
37 "libthr", /* thread library */
40 "libargp", /* workarounds for glibc-less systems */
41 "libasan", /* gcc sanitizers */
44 "libboost_context-mt",
45 "libboost_stacktrace_addr2line",
46 "libboost_stacktrace_backtrace",
83 "libtsan", /* gcc sanitizers */
84 "libubsan", /* gcc sanitizers */
90 "libkrb5support", /*odd behaviour on fedora rawhide ... remove these when fixed*/
114 static bool is_simgrid_lib(const std::string& libname)
116 return libname == "libsimgrid";
119 static bool is_filtered_lib(const std::string& libname)
121 return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
124 static std::string get_lib_name(const std::string& pathname)
126 std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
129 size_t pos = map_basename.rfind(".so");
130 if (pos != std::string::npos) {
131 // strip the extension (matching regex "\.so.*$")
132 libname.assign(map_basename, 0, pos);
134 // strip the version suffix (matching regex "-[.0-9-]*$")
136 pos = libname.rfind('-');
137 if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
146 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
148 char* buffer = (char*)buf;
149 ssize_t real_count = count;
151 ssize_t res = pread(fd, buffer, count, offset);
158 else if (errno != EINTR) {
159 perror("pread_whole");
166 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
168 const char* buffer = (const char*)buf;
169 ssize_t real_count = count;
171 ssize_t res = pwrite(fd, buffer, count, offset);
178 else if (errno != EINTR)
184 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
185 static const void* zero_buffer;
186 static const size_t zero_buffer_size = 10 * 4096;
188 static void zero_buffer_init()
190 int fd = open("/dev/zero", O_RDONLY);
192 xbt_die("Could not open /dev/zero");
193 zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
194 if (zero_buffer == MAP_FAILED)
195 xbt_die("Could not map the zero buffer");
199 int open_vm(pid_t pid, int flags)
201 const size_t buffer_size = 30;
202 char buffer[buffer_size];
203 int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long)pid);
204 if (res < 0 || (size_t)res >= buffer_size) {
205 errno = ENAMETOOLONG;
208 return open(buffer, flags);
213 RemoteClient::RemoteClient(pid_t pid, int sockfd) : AddressSpace(this), pid_(pid), channel_(sockfd), running_(true)
217 void RemoteClient::init()
219 this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
220 this->init_memory_map_info();
222 int fd = open_vm(this->pid_, O_RDWR);
224 xbt_die("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 if (not std_heap_var)
230 xbt_die("No heap information in the target process");
231 if (not std_heap_var->address)
232 xbt_die("No constant address for this variable");
233 this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address));
235 this->smx_actors_infos.clear();
236 this->smx_dead_actors_infos.clear();
237 this->unw_addr_space = simgrid::mc::UnwindContext::createUnwindAddressSpace();
238 this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
239 this->unw_underlying_context = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
242 RemoteClient::~RemoteClient()
244 if (this->memory_file >= 0)
245 close(this->memory_file);
247 if (this->unw_underlying_addr_space != unw_local_addr_space) {
248 if (this->unw_underlying_addr_space)
249 unw_destroy_addr_space(this->unw_underlying_addr_space);
250 if (this->unw_underlying_context)
251 _UPT_destroy(this->unw_underlying_context);
254 unw_destroy_addr_space(this->unw_addr_space);
257 /** Refresh the information about the process
259 * Do not use directly, this is used by the getters when appropriate
260 * in order to have fresh data.
262 void RemoteClient::refresh_heap()
264 // Read/dereference/refresh the std_heap pointer:
266 this->heap.reset(new s_xbt_mheap_t());
267 this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address));
268 this->cache_flags_ |= RemoteClient::cache_heap;
271 /** Refresh the information about the process
273 * Do not use directly, this is used by the getters when appropriate
274 * in order to have fresh data.
276 void RemoteClient::refresh_malloc_info()
278 // Refresh process->heapinfo:
279 if (this->cache_flags_ & RemoteClient::cache_malloc)
281 size_t count = this->heap->heaplimit + 1;
282 if (this->heap_info.size() < count)
283 this->heap_info.resize(count);
284 this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo));
285 this->cache_flags_ |= RemoteClient::cache_malloc;
288 /** @brief Finds the range of the different memory segments and binary paths */
289 void RemoteClient::init_memory_map_info()
291 XBT_DEBUG("Get debug information ...");
292 this->maestro_stack_start_ = nullptr;
293 this->maestro_stack_end_ = nullptr;
294 this->object_infos.resize(0);
295 this->binary_info = nullptr;
296 this->libsimgrid_info = nullptr;
298 std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
300 const char* current_name = nullptr;
302 this->object_infos.clear();
304 for (size_t i = 0; i < maps.size(); i++) {
305 simgrid::xbt::VmMap const& reg = maps[i];
306 const char* pathname = maps[i].pathname.c_str();
309 if (maps[i].pathname.empty()) {
310 current_name = nullptr;
314 // [stack], [vvar], [vsyscall], [vdso] ...
315 if (pathname[0] == '[') {
316 if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
317 this->maestro_stack_start_ = remote(reg.start_addr);
318 this->maestro_stack_end_ = remote(reg.end_addr);
320 current_name = nullptr;
324 if (current_name && strcmp(current_name, pathname) == 0)
327 current_name = pathname;
328 if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
331 const bool is_executable = not i;
333 if (not is_executable) {
334 libname = get_lib_name(pathname);
335 if (is_filtered_lib(libname)) {
340 std::shared_ptr<simgrid::mc::ObjectInformation> info =
341 simgrid::mc::createObjectInformation(this->memory_map_, pathname);
342 this->object_infos.push_back(info);
344 this->binary_info = info;
345 else if (is_simgrid_lib(libname))
346 this->libsimgrid_info = info;
349 // Resolve time (including across different objects):
350 for (auto const& object_info : this->object_infos)
351 postProcessObjectInformation(this, object_info.get());
353 xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
354 xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
356 XBT_DEBUG("Get debug information done !");
359 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteClient::find_object_info(RemotePtr<void> addr) const
361 for (auto const& object_info : this->object_infos)
362 if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
367 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_exec(RemotePtr<void> addr) const
369 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
370 if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
375 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_rw(RemotePtr<void> addr) const
377 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
378 if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
383 simgrid::mc::Frame* RemoteClient::find_function(RemotePtr<void> ip) const
385 std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
386 return info ? info->find_function((void*)ip.address()) : nullptr;
389 /** Find (one occurrence of) the named variable definition
391 const simgrid::mc::Variable* RemoteClient::find_variable(const char* name) const
393 // First lookup the variable in the executable shared object.
394 // A global variable used directly by the executable code from a library
395 // is reinstantiated in the executable memory .data/.bss.
396 // We need to look up the variable in the executable first.
397 if (this->binary_info) {
398 std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
399 const simgrid::mc::Variable* var = info->find_variable(name);
404 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
405 const simgrid::mc::Variable* var = info->find_variable(name);
413 void RemoteClient::read_variable(const char* name, void* target, size_t size) const
415 const simgrid::mc::Variable* var = this->find_variable(name);
416 xbt_assert(var, "Variable %s not found", name);
417 xbt_assert(var->address, "No simple location for this variable");
418 xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
419 xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
420 size, (size_t)var->type->full_type->byte_size);
421 this->read_bytes(target, size, remote(var->address));
424 std::string RemoteClient::read_string(RemotePtr<char> address) const
429 std::vector<char> res(128);
433 ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
434 if (c == -1 && errno == EINTR)
436 xbt_assert(c > 0, "Could not read string from remote process");
438 const void* p = memchr(res.data() + off, '\0', c);
440 return std::string(res.data());
443 if (off == (off_t)res.size())
444 res.resize(res.size() * 2);
448 void* RemoteClient::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address, ReadOptions /*options*/) const
450 if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
451 xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
455 /** Write data to a process memory
457 * @param buffer local memory address (source)
458 * @param len data size
459 * @param address target process memory address (target)
461 void RemoteClient::write_bytes(const void* buffer, size_t len, RemotePtr<void> address)
463 if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
464 xbt_die("Write to process %lli failed", (long long)this->pid_);
467 void RemoteClient::clear_bytes(RemotePtr<void> address, size_t len)
469 pthread_once(&zero_buffer_flag, zero_buffer_init);
471 size_t s = len > zero_buffer_size ? zero_buffer_size : len;
472 this->write_bytes(zero_buffer, s, address);
473 address = remote((char*)address.address() + s);
478 void RemoteClient::ignore_region(std::uint64_t addr, std::size_t size)
480 IgnoredRegion region;
484 if (ignored_regions_.empty()) {
485 ignored_regions_.push_back(region);
489 unsigned int cursor = 0;
490 const IgnoredRegion* current_region = nullptr;
493 int end = ignored_regions_.size() - 1;
494 while (start <= end) {
495 cursor = (start + end) / 2;
496 current_region = &ignored_regions_[cursor];
497 if (current_region->addr == addr) {
498 if (current_region->size == size)
500 else if (current_region->size < size)
504 } else if (current_region->addr < addr)
510 std::size_t position;
511 if (current_region->addr == addr) {
512 if (current_region->size < size)
513 position = cursor + 1;
516 } else if (current_region->addr < addr)
517 position = cursor + 1;
520 ignored_regions_.insert(ignored_regions_.begin() + position, region);
523 void RemoteClient::ignore_heap(IgnoredHeapRegion const& region)
525 if (ignored_heap_.empty()) {
526 ignored_heap_.push_back(std::move(region));
530 typedef std::vector<IgnoredHeapRegion>::size_type size_type;
533 size_type end = ignored_heap_.size() - 1;
535 // Binary search the position of insertion:
537 while (start <= end) {
538 cursor = start + (end - start) / 2;
539 auto const& current_region = ignored_heap_[cursor];
540 if (current_region.address == region.address)
542 else if (current_region.address < region.address)
544 else if (cursor != 0)
551 // Insert it mc_heap_ignore_region_t:
552 if (ignored_heap_[cursor].address < region.address)
554 ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
557 void RemoteClient::unignore_heap(void* address, size_t size)
559 typedef std::vector<IgnoredHeapRegion>::size_type size_type;
562 size_type end = ignored_heap_.size() - 1;
566 while (start <= end) {
567 cursor = (start + end) / 2;
568 auto const& region = ignored_heap_[cursor];
569 if (region.address < address)
571 else if ((char*)region.address <= ((char*)address + size)) {
572 ignored_heap_.erase(ignored_heap_.begin() + cursor);
574 } else if (cursor != 0)
582 void RemoteClient::ignore_local_variable(const char* var_name, const char* frame_name)
584 if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
585 frame_name = nullptr;
586 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
587 info->remove_local_variable(var_name, frame_name);
590 std::vector<simgrid::mc::ActorInformation>& RemoteClient::actors()
592 this->refresh_simix();
593 return smx_actors_infos;
596 std::vector<simgrid::mc::ActorInformation>& RemoteClient::dead_actors()
598 this->refresh_simix();
599 return smx_dead_actors_infos;
602 void RemoteClient::dump_stack()
604 unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
606 XBT_ERROR("Could not initialize ptrace address space");
610 void* context = _UPT_create(this->pid_);
611 if (context == nullptr) {
612 unw_destroy_addr_space(as);
613 XBT_ERROR("Could not initialize ptrace context");
618 if (unw_init_remote(&cursor, as, context) != 0) {
619 _UPT_destroy(context);
620 unw_destroy_addr_space(as);
621 XBT_ERROR("Could not initialiez ptrace cursor");
625 simgrid::mc::dumpStack(stderr, &cursor);
627 _UPT_destroy(context);
628 unw_destroy_addr_space(as);
631 bool RemoteClient::actor_is_enabled(aid_t pid)
633 s_mc_message_actor_enabled_t msg{MC_MESSAGE_ACTOR_ENABLED, pid};
634 process()->get_channel().send(msg);
635 char buff[MC_MESSAGE_LENGTH];
636 ssize_t received = process()->get_channel().receive(buff, MC_MESSAGE_LENGTH, true);
637 xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
638 return ((s_mc_message_int_t*)buff)->value;