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[simgrid.git] / src / mc / remote / RemoteClient.cpp
1 /* Copyright (c) 2014-2018. 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     "libasan", /* gcc sanitizers */
68     "libargp", /* workarounds for glibc-less systems */
69     "libtsan",
70     "libubsan",
71     "libbz2",
72     "libboost_chrono",
73     "libboost_context",
74     "libboost_context-mt",
75     "libboost_system",
76     "libboost_thread",
77     "libboost_timer",
78     "libboost_unit_test_framework",
79     "libc",
80     "libc++",
81     "libcdt",
82     "libcgraph",
83     "libcrypto",
84     "libcxxrt",
85     "libdl",
86     "libdw",
87     "libelf",
88     "libevent",
89     "libgcc_s",
90     "libimf",
91     "libintlc",
92     "libirng",
93     "liblua5.1",
94     "liblua5.3",
95     "liblzma",
96     "libm",
97     "libpapi",
98     "libpfm",
99     "libpthread",
100     "librt",
101     "libstdc++",
102     "libsvml",
103     "libunwind",
104     "libunwind-x86_64",
105     "libunwind-x86",
106     "libunwind-ptrace",
107     "libz"};
108
109 static bool is_simgrid_lib(const std::string& libname)
110 {
111   return libname == "libsimgrid";
112 }
113
114 static bool is_filtered_lib(const std::string& libname)
115 {
116   return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
117 }
118
119 static std::string get_lib_name(const std::string& pathname)
120 {
121   std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
122   std::string libname;
123
124   size_t pos = map_basename.rfind(".so");
125   if (pos != std::string::npos) {
126     // strip the extension (matching regex "\.so.*$")
127     libname.assign(map_basename, 0, pos);
128
129     // strip the version suffix (matching regex "-[.0-9-]*$")
130     while (true) {
131       pos = libname.rfind('-');
132       if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
133         break;
134       libname.erase(pos);
135     }
136   }
137
138   return libname;
139 }
140
141 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
142 {
143   char* buffer       = (char*)buf;
144   ssize_t real_count = count;
145   while (count) {
146     ssize_t res = pread(fd, buffer, count, offset);
147     if (res > 0) {
148       count -= res;
149       buffer += res;
150       offset += res;
151     } else if (res == 0)
152       return -1;
153     else if (errno != EINTR) {
154       perror("pread_whole");
155       return -1;
156     }
157   }
158   return real_count;
159 }
160
161 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
162 {
163   const char* buffer = (const char*)buf;
164   ssize_t real_count = count;
165   while (count) {
166     ssize_t res = pwrite(fd, buffer, count, offset);
167     if (res > 0) {
168       count -= res;
169       buffer += res;
170       offset += res;
171     } else if (res == 0)
172       return -1;
173     else if (errno != EINTR)
174       return -1;
175   }
176   return real_count;
177 }
178
179 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
180 static const void* zero_buffer;
181 static const size_t zero_buffer_size = 10 * 4096;
182
183 static void zero_buffer_init()
184 {
185   int fd = open("/dev/zero", O_RDONLY);
186   if (fd < 0)
187     xbt_die("Could not open /dev/zero");
188   zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
189   if (zero_buffer == MAP_FAILED)
190     xbt_die("Could not map the zero buffer");
191   close(fd);
192 }
193
194 int open_vm(pid_t pid, int flags)
195 {
196   const size_t buffer_size = 30;
197   char buffer[buffer_size];
198   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long)pid);
199   if (res < 0 || (size_t)res >= buffer_size) {
200     errno = ENAMETOOLONG;
201     return -1;
202   }
203   return open(buffer, flags);
204 }
205
206 // ***** Process
207
208 RemoteClient::RemoteClient(pid_t pid, int sockfd) : AddressSpace(this), pid_(pid), channel_(sockfd), running_(true)
209 {
210 }
211
212 void RemoteClient::init()
213 {
214   this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
215   this->init_memory_map_info();
216
217   int fd = open_vm(this->pid_, O_RDWR);
218   if (fd < 0)
219     xbt_die("Could not open file for process virtual address space");
220   this->memory_file = fd;
221
222   // Read std_heap (is a struct mdesc*):
223   simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
224   if (not std_heap_var)
225     xbt_die("No heap information in the target process");
226   if (not std_heap_var->address)
227     xbt_die("No constant address for this variable");
228   this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address),
229                    simgrid::mc::ProcessIndexDisabled);
230
231   this->smx_actors_infos.clear();
232   this->smx_dead_actors_infos.clear();
233   this->unw_addr_space            = simgrid::mc::UnwindContext::createUnwindAddressSpace();
234   this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
235   this->unw_underlying_context    = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
236 }
237
238 RemoteClient::~RemoteClient()
239 {
240   if (this->memory_file >= 0)
241     close(this->memory_file);
242
243   if (this->unw_underlying_addr_space != unw_local_addr_space) {
244     if (this->unw_underlying_addr_space)
245       unw_destroy_addr_space(this->unw_underlying_addr_space);
246     if (this->unw_underlying_context)
247       _UPT_destroy(this->unw_underlying_context);
248   }
249
250   unw_destroy_addr_space(this->unw_addr_space);
251 }
252
253 /** Refresh the information about the process
254  *
255  *  Do not use directly, this is used by the getters when appropriate
256  *  in order to have fresh data.
257  */
258 void RemoteClient::refresh_heap()
259 {
260   // Read/dereference/refresh the std_heap pointer:
261   if (not this->heap)
262     this->heap = std::unique_ptr<s_xbt_mheap_t>(new s_xbt_mheap_t());
263   this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address), simgrid::mc::ProcessIndexDisabled);
264   this->cache_flags_ |= RemoteClient::cache_heap;
265 }
266
267 /** Refresh the information about the process
268  *
269  *  Do not use direclty, this is used by the getters when appropriate
270  *  in order to have fresh data.
271  * */
272 void RemoteClient::refresh_malloc_info()
273 {
274   // Refresh process->heapinfo:
275   if (this->cache_flags_ & RemoteClient::cache_malloc)
276     return;
277   size_t count = this->heap->heaplimit + 1;
278   if (this->heap_info.size() < count)
279     this->heap_info.resize(count);
280   this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo),
281                    simgrid::mc::ProcessIndexDisabled);
282   this->cache_flags_ |= RemoteClient::cache_malloc;
283 }
284
285 /** @brief Finds the range of the different memory segments and binary paths */
286 void RemoteClient::init_memory_map_info()
287 {
288   XBT_DEBUG("Get debug information ...");
289   this->maestro_stack_start_ = nullptr;
290   this->maestro_stack_end_   = nullptr;
291   this->object_infos.resize(0);
292   this->binary_info     = nullptr;
293   this->libsimgrid_info = nullptr;
294
295   std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
296
297   const char* current_name = nullptr;
298
299   this->object_infos.clear();
300
301   for (size_t i = 0; i < maps.size(); i++) {
302     simgrid::xbt::VmMap const& reg = maps[i];
303     const char* pathname           = maps[i].pathname.c_str();
304
305     // Nothing to do
306     if (maps[i].pathname.empty()) {
307       current_name = nullptr;
308       continue;
309     }
310
311     // [stack], [vvar], [vsyscall], [vdso] ...
312     if (pathname[0] == '[') {
313       if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
314         this->maestro_stack_start_ = remote(reg.start_addr);
315         this->maestro_stack_end_   = remote(reg.end_addr);
316       }
317       current_name = nullptr;
318       continue;
319     }
320
321     if (current_name && strcmp(current_name, pathname) == 0)
322       continue;
323
324     current_name = pathname;
325     if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
326       continue;
327
328     const bool is_executable = not i;
329     std::string libname;
330     if (not is_executable) {
331       libname = get_lib_name(pathname);
332       if (is_filtered_lib(libname)) {
333         continue;
334       }
335     }
336
337     std::shared_ptr<simgrid::mc::ObjectInformation> info =
338         simgrid::mc::createObjectInformation(this->memory_map_, pathname);
339     this->object_infos.push_back(info);
340     if (is_executable)
341       this->binary_info = info;
342     else if (is_simgrid_lib(libname))
343       this->libsimgrid_info = info;
344   }
345
346   // Resolve time (including across different objects):
347   for (auto const& object_info : this->object_infos)
348     postProcessObjectInformation(this, object_info.get());
349
350   xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
351   xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
352
353   XBT_DEBUG("Get debug information done !");
354 }
355
356 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteClient::find_object_info(RemotePtr<void> addr) const
357 {
358   for (auto const& object_info : this->object_infos)
359     if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
360       return object_info;
361   return nullptr;
362 }
363
364 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_exec(RemotePtr<void> addr) const
365 {
366   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
367     if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
368       return info;
369   return nullptr;
370 }
371
372 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_rw(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_rw && addr.address() <= (std::uint64_t)info->end_rw)
376       return info;
377   return nullptr;
378 }
379
380 simgrid::mc::Frame* RemoteClient::find_function(RemotePtr<void> ip) const
381 {
382   std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
383   return info ? info->find_function((void*)ip.address()) : nullptr;
384 }
385
386 /** Find (one occurrence of) the named variable definition
387  */
388 simgrid::mc::Variable* RemoteClient::find_variable(const char* name) const
389 {
390   // First lookup the variable in the executable shared object.
391   // A global variable used directly by the executable code from a library
392   // is reinstanciated in the executable memory .data/.bss.
393   // We need to look up the variable in the executable first.
394   if (this->binary_info) {
395     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
396     simgrid::mc::Variable* var                                  = info->find_variable(name);
397     if (var)
398       return var;
399   }
400
401   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
402     simgrid::mc::Variable* var = info->find_variable(name);
403     if (var)
404       return var;
405   }
406
407   return nullptr;
408 }
409
410 void RemoteClient::read_variable(const char* name, void* target, size_t size) const
411 {
412   simgrid::mc::Variable* var = this->find_variable(name);
413   xbt_assert(var->address, "No simple location for this variable");
414   xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
415   xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
416              size, (size_t)var->type->full_type->byte_size);
417   this->read_bytes(target, size, remote(var->address));
418 }
419
420 std::string RemoteClient::read_string(RemotePtr<char> address) const
421 {
422   if (not address)
423     return {};
424
425   std::vector<char> res(128);
426   off_t off = 0;
427
428   while (1) {
429     ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
430     if (c == -1) {
431       if (errno == EINTR)
432         continue;
433       else
434         xbt_die("Could not read from from remote process");
435     }
436     if (c == 0)
437       xbt_die("Could not read string from remote process");
438
439     void* p = memchr(res.data() + off, '\0', c);
440     if (p)
441       return std::string(res.data());
442
443     off += c;
444     if (off == (off_t)res.size())
445       res.resize(res.size() * 2);
446   }
447 }
448
449 const void* RemoteClient::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address, int process_index,
450                                      ReadOptions options) const
451 {
452   if (process_index != simgrid::mc::ProcessIndexDisabled) {
453     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->find_object_info_rw(address);
454 // Segment overlap is not handled.
455 #if HAVE_SMPI
456     if (info.get() && this->privatized(*info)) {
457       if (process_index < 0)
458         xbt_die("Missing process index");
459       if (process_index >= (int)MC_smpi_process_count())
460         xbt_die("Invalid process index");
461
462       // Read smpi_privatization_regions from MCed:
463       smpi_privatization_region_t remote_smpi_privatization_regions =
464           mc_model_checker->process().read_variable<smpi_privatization_region_t>("smpi_privatization_regions");
465
466       s_smpi_privatization_region_t privatization_region =
467           mc_model_checker->process().read<s_smpi_privatization_region_t>(
468               remote(remote_smpi_privatization_regions + process_index));
469
470       // Address translation in the privatization segment:
471       size_t offset = address.address() - (std::uint64_t)info->start_rw;
472       address       = remote((char*)privatization_region.address + offset);
473     }
474 #endif
475   }
476   if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
477     xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
478   return buffer;
479 }
480
481 /** Write data to a process memory
482  *
483  *  @param buffer   local memory address (source)
484  *  @param len      data size
485  *  @param address  target process memory address (target)
486  */
487 void RemoteClient::write_bytes(const void* buffer, size_t len, RemotePtr<void> address)
488 {
489   if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
490     xbt_die("Write to process %lli failed", (long long)this->pid_);
491 }
492
493 void RemoteClient::clear_bytes(RemotePtr<void> address, size_t len)
494 {
495   pthread_once(&zero_buffer_flag, zero_buffer_init);
496   while (len) {
497     size_t s = len > zero_buffer_size ? zero_buffer_size : len;
498     this->write_bytes(zero_buffer, s, address);
499     address = remote((char*)address.address() + s);
500     len -= s;
501   }
502 }
503
504 void RemoteClient::ignore_region(std::uint64_t addr, std::size_t size)
505 {
506   IgnoredRegion region;
507   region.addr = addr;
508   region.size = size;
509
510   if (ignored_regions_.empty()) {
511     ignored_regions_.push_back(region);
512     return;
513   }
514
515   unsigned int cursor           = 0;
516   IgnoredRegion* current_region = nullptr;
517
518   int start = 0;
519   int end   = ignored_regions_.size() - 1;
520   while (start <= end) {
521     cursor         = (start + end) / 2;
522     current_region = &ignored_regions_[cursor];
523     if (current_region->addr == addr) {
524       if (current_region->size == size)
525         return;
526       else if (current_region->size < size)
527         start = cursor + 1;
528       else
529         end = cursor - 1;
530     } else if (current_region->addr < addr)
531       start = cursor + 1;
532     else
533       end = cursor - 1;
534   }
535
536   std::size_t position;
537   if (current_region->addr == addr) {
538     if (current_region->size < size)
539       position = cursor + 1;
540     else
541       position = cursor;
542   } else if (current_region->addr < addr)
543     position = cursor + 1;
544   else
545     position = cursor;
546   ignored_regions_.insert(ignored_regions_.begin() + position, region);
547 }
548
549 void RemoteClient::ignore_heap(IgnoredHeapRegion const& region)
550 {
551   if (ignored_heap_.empty()) {
552     ignored_heap_.push_back(std::move(region));
553     return;
554   }
555
556   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
557
558   size_type start = 0;
559   size_type end   = ignored_heap_.size() - 1;
560
561   // Binary search the position of insertion:
562   size_type cursor;
563   while (start <= end) {
564     cursor               = start + (end - start) / 2;
565     auto& current_region = ignored_heap_[cursor];
566     if (current_region.address == region.address)
567       return;
568     else if (current_region.address < region.address)
569       start = cursor + 1;
570     else if (cursor != 0)
571       end = cursor - 1;
572     // Avoid underflow:
573     else
574       break;
575   }
576
577   // Insert it mc_heap_ignore_region_t:
578   if (ignored_heap_[cursor].address < region.address)
579     ++cursor;
580   ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
581 }
582
583 void RemoteClient::unignore_heap(void* address, size_t size)
584 {
585   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
586
587   size_type start = 0;
588   size_type end   = ignored_heap_.size() - 1;
589
590   // Binary search:
591   size_type cursor;
592   while (start <= end) {
593     cursor       = (start + end) / 2;
594     auto& region = ignored_heap_[cursor];
595     if (region.address < address)
596       start = cursor + 1;
597     else if ((char*)region.address <= ((char*)address + size)) {
598       ignored_heap_.erase(ignored_heap_.begin() + cursor);
599       return;
600     } else if (cursor != 0)
601       end = cursor - 1;
602     // Avoid underflow:
603     else
604       break;
605   }
606 }
607
608 void RemoteClient::ignore_local_variable(const char* var_name, const char* frame_name)
609 {
610   if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
611     frame_name = nullptr;
612   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
613     info->remove_local_variable(var_name, frame_name);
614 }
615
616 std::vector<simgrid::mc::ActorInformation>& RemoteClient::actors()
617 {
618   this->refresh_simix();
619   return smx_actors_infos;
620 }
621
622 std::vector<simgrid::mc::ActorInformation>& RemoteClient::dead_actors()
623 {
624   this->refresh_simix();
625   return smx_dead_actors_infos;
626 }
627
628 void RemoteClient::dumpStack()
629 {
630   unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
631   if (as == nullptr) {
632     XBT_ERROR("Could not initialize ptrace address space");
633     return;
634   }
635
636   void* context = _UPT_create(this->pid_);
637   if (context == nullptr) {
638     unw_destroy_addr_space(as);
639     XBT_ERROR("Could not initialize ptrace context");
640     return;
641   }
642
643   unw_cursor_t cursor;
644   if (unw_init_remote(&cursor, as, context) != 0) {
645     _UPT_destroy(context);
646     unw_destroy_addr_space(as);
647     XBT_ERROR("Could not initialiez ptrace cursor");
648     return;
649   }
650
651   simgrid::mc::dumpStack(stderr, cursor);
652
653   _UPT_destroy(context);
654   unw_destroy_addr_space(as);
655 }
656
657 bool RemoteClient::actor_is_enabled(aid_t pid)
658 {
659   s_mc_message_actor_enabled_t msg{MC_MESSAGE_ACTOR_ENABLED, pid};
660   process()->getChannel().send(msg);
661   char buff[MC_MESSAGE_LENGTH];
662   ssize_t received = process()->getChannel().receive(buff, MC_MESSAGE_LENGTH, true);
663   xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
664   return ((s_mc_message_int_t*)buff)->value;
665 }
666 }
667 }