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[mc] Add ctor/dtor for s_mc_object_info
[simgrid.git] / src / mc / mc_process.cpp
1 /* Copyright (c) 2014-2015. The SimGrid Team.
2  * All rights reserved.                                                     */
3
4 /* This program is free software; you can redistribute it and/or modify it
5  * under the terms of the license (GNU LGPL) which comes with this package. */
6
7 #include <assert.h>
8 #include <stddef.h>
9 #include <stdbool.h>
10 #include <stdint.h>
11 #include <errno.h>
12
13 #include <sys/types.h>
14 #include <fcntl.h>
15 #include <unistd.h>
16 #include <regex.h>
17 #include <sys/mman.h> // PROT_*
18
19 #include <pthread.h>
20
21 #include <libgen.h>
22
23 #include <libunwind.h>
24 #include <libunwind-ptrace.h>
25
26 #include <xbt/mmalloc.h>
27
28 #include "mc_process.h"
29 #include "mc_object_info.h"
30 #include "AddressSpace.hpp"
31 #include "mc_unw.h"
32 #include "mc_snapshot.h"
33 #include "mc_ignore.h"
34 #include "mc_smx.h"
35 #include "mc_server.h"
36
37 using simgrid::mc::remote;
38
39 extern "C" {
40
41 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc,
42                                 "MC process information");
43
44 // ***** Helper stuff
45
46 #define SO_RE "\\.so[\\.0-9]*$"
47 #define VERSION_RE "-[\\.0-9]*$"
48
49 static const char *const FILTERED_LIBS[] = {
50   "libstdc++",
51   "libboost_context",
52   "libc++",
53   "libm",
54   "libgcc_s",
55   "libpthread",
56   "libunwind",
57   "libunwind-x86_64",
58   "libunwind-x86",
59   "libunwind-ptrace",
60   "libdw",
61   "libdl",
62   "librt",
63   "liblzma",
64   "libelf",
65   "libbz2",
66   "libz",
67   "libelf",
68   "libc",
69   "ld"
70 };
71
72 static bool MC_is_simgrid_lib(const char* libname)
73 {
74   return !strcmp(libname, "libsimgrid");
75 }
76
77 static bool MC_is_filtered_lib(const char* libname)
78 {
79   for (const char* filtered_lib : FILTERED_LIBS)
80     if (strcmp(libname, filtered_lib)==0)
81       return true;
82   return false;
83 }
84
85 struct s_mc_memory_map_re {
86   regex_t so_re;
87   regex_t version_re;
88 };
89
90 static char* MC_get_lib_name(const char* pathname, struct s_mc_memory_map_re* res)
91 {
92   const char* map_basename = basename((char*) pathname);
93
94   regmatch_t match;
95   if(regexec(&res->so_re, map_basename, 1, &match, 0))
96     return NULL;
97
98   char* libname = strndup(map_basename, match.rm_so);
99
100   // Strip the version suffix:
101   if(libname && !regexec(&res->version_re, libname, 1, &match, 0)) {
102     char* temp = libname;
103     libname = strndup(temp, match.rm_so);
104     free(temp);
105   }
106
107   return libname;
108 }
109
110 static ssize_t pread_whole(int fd, void *buf, size_t count, off_t offset)
111 {
112   char* buffer = (char*) buf;
113   ssize_t real_count = count;
114   while (count) {
115     ssize_t res = pread(fd, buffer, count, offset);
116     if (res > 0) {
117       count  -= res;
118       buffer += res;
119       offset += res;
120     } else if (res==0) {
121       return -1;
122     } else if (errno != EINTR) {
123       return -1;
124     }
125   }
126   return real_count;
127 }
128
129 static ssize_t pwrite_whole(int fd, const void *buf, size_t count, off_t offset)
130 {
131   const char* buffer = (const char*) buf;
132   ssize_t real_count = count;
133   while (count) {
134     ssize_t res = pwrite(fd, buffer, count, offset);
135     if (res > 0) {
136       count  -= res;
137       buffer += res;
138       offset += res;
139     } else if (res==0) {
140       return -1;
141     } else if (errno != EINTR) {
142       return -1;
143     }
144   }
145   return real_count;
146 }
147
148 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
149 static const void* zero_buffer;
150 static const size_t zero_buffer_size = 10 * 4096;
151
152 static void MC_zero_buffer_init(void)
153 {
154   int fd = open("/dev/zero", O_RDONLY);
155   if (fd<0)
156     xbt_die("Could not open /dev/zero");
157   zero_buffer = mmap(NULL, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
158   if (zero_buffer == MAP_FAILED)
159     xbt_die("Could not map the zero buffer");
160   close(fd);
161 }
162
163 }
164
165 namespace simgrid {
166 namespace mc {
167
168 int open_vm(pid_t pid, int flags)
169 {
170   const size_t buffer_size = 30;
171   char buffer[buffer_size];
172   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long) pid);
173   if (res < 0 || (size_t) res >= buffer_size) {
174     errno = ENAMETOOLONG;
175     return -1;
176   }
177   return open(buffer, flags);
178 }
179
180   
181 }
182 }
183
184 // ***** Process
185
186 namespace simgrid {
187 namespace mc {
188
189 Process::Process(pid_t pid, int sockfd)
190 {
191   Process* process = this;
192
193   process->process_flags = MC_PROCESS_NO_FLAG;
194   process->socket_ = sockfd;
195   process->pid_ = pid;
196   if (pid==getpid())
197     process->process_flags |= MC_PROCESS_SELF_FLAG;
198   process->running_ = true;
199   process->status_ = 0;
200   process->memory_map_ = get_memory_map(pid);
201   process->cache_flags = MC_PROCESS_CACHE_FLAG_NONE;
202   process->heap = NULL;
203   process->heap_info = NULL;
204   process->init_memory_map_info();
205
206   // Open the memory file
207   if (process->is_self())
208     process->memory_file = -1;
209   else {
210     int fd = open_vm(process->pid_, O_RDWR);
211     if (fd<0)
212       xbt_die("Could not open file for process virtual address space");
213     process->memory_file = fd;
214   }
215
216   // Read std_heap (is a struct mdesc*):
217   dw_variable_t std_heap_var = process->find_variable("__mmalloc_default_mdp");
218   if (!std_heap_var)
219     xbt_die("No heap information in the target process");
220   if(!std_heap_var->address)
221     xbt_die("No constant address for this variable");
222   process->read_bytes(&process->heap_address, sizeof(struct mdesc*),
223     remote(std_heap_var->address),
224     simgrid::mc::ProcessIndexDisabled);
225
226   process->smx_process_infos = MC_smx_process_info_list_new();
227   process->smx_old_process_infos = MC_smx_process_info_list_new();
228
229   process->unw_addr_space = unw_create_addr_space(&mc_unw_accessors  , __BYTE_ORDER);
230   if (process->process_flags & MC_PROCESS_SELF_FLAG) {
231     process->unw_underlying_addr_space = unw_local_addr_space;
232     process->unw_underlying_context = NULL;
233   } else {
234     process->unw_underlying_addr_space = unw_create_addr_space(&mc_unw_vmread_accessors, __BYTE_ORDER);
235     process->unw_underlying_context = _UPT_create(pid);
236   }
237 }
238
239 Process::~Process()
240 {
241   Process* process = this;
242
243   if (this->socket_ >= 0 && close(this->socket_) < 0)
244     xbt_die("Could not close communication socket");
245
246   process->process_flags = MC_PROCESS_NO_FLAG;
247   process->pid_ = 0;
248
249   process->maestro_stack_start_ = nullptr;
250   process->maestro_stack_end_ = nullptr;
251
252   xbt_dynar_free(&process->smx_process_infos);
253   xbt_dynar_free(&process->smx_old_process_infos);
254
255   size_t i;
256   for (i=0; i!=process->object_infos_size; ++i) {
257     delete process->object_infos[i];
258     process->object_infos[i] = nullptr;
259   }
260   free(process->object_infos);
261   process->object_infos = NULL;
262   process->object_infos_size = 0;
263   if (process->memory_file >= 0) {
264     close(process->memory_file);
265   }
266
267   if (process->unw_underlying_addr_space != unw_local_addr_space) {
268     unw_destroy_addr_space(process->unw_underlying_addr_space);
269     _UPT_destroy(process->unw_underlying_context);
270   }
271   process->unw_underlying_context = NULL;
272   process->unw_underlying_addr_space = NULL;
273
274   unw_destroy_addr_space(process->unw_addr_space);
275   process->unw_addr_space = NULL;
276
277   process->cache_flags = MC_PROCESS_CACHE_FLAG_NONE;
278
279   free(process->heap);
280   process->heap = NULL;
281
282   free(process->heap_info);
283   process->heap_info = NULL;
284 }
285
286 /** Refresh the information about the process
287  *
288  *  Do not use direclty, this is used by the getters when appropriate
289  *  in order to have fresh data.
290  */
291 void Process::refresh_heap()
292 {
293   xbt_assert(mc_mode == MC_MODE_SERVER);
294   xbt_assert(!this->is_self());
295   // Read/dereference/refresh the std_heap pointer:
296   if (!this->heap) {
297     this->heap = (struct mdesc*) malloc(sizeof(struct mdesc));
298   }
299   this->read_bytes(this->heap, sizeof(struct mdesc), remote(this->heap_address),
300     simgrid::mc::ProcessIndexDisabled);
301   this->cache_flags |= MC_PROCESS_CACHE_FLAG_HEAP;
302 }
303
304 /** Refresh the information about the process
305  *
306  *  Do not use direclty, this is used by the getters when appropriate
307  *  in order to have fresh data.
308  * */
309 void Process::refresh_malloc_info()
310 {
311   xbt_assert(mc_mode == MC_MODE_SERVER);
312   xbt_assert(!this->is_self());
313   if (!(this->cache_flags & MC_PROCESS_CACHE_FLAG_HEAP))
314     this->refresh_heap();
315   // Refresh process->heapinfo:
316   size_t malloc_info_bytesize =
317     (this->heap->heaplimit + 1) * sizeof(malloc_info);
318   this->heap_info = (malloc_info*) realloc(this->heap_info, malloc_info_bytesize);
319   this->read_bytes(this->heap_info, malloc_info_bytesize,
320     remote(this->heap->heapinfo), simgrid::mc::ProcessIndexDisabled);
321   this->cache_flags |= MC_PROCESS_CACHE_FLAG_MALLOC_INFO;
322 }
323
324 /** @brief Finds the range of the different memory segments and binary paths */
325 void Process::init_memory_map_info()
326 {
327   XBT_DEBUG("Get debug information ...");
328   this->maestro_stack_start_ = nullptr;
329   this->maestro_stack_end_ = nullptr;
330   this->object_infos = NULL;
331   this->object_infos_size = 0;
332   this->binary_info = NULL;
333   this->libsimgrid_info = NULL;
334
335   struct s_mc_memory_map_re res;
336
337   if(regcomp(&res.so_re, SO_RE, 0) || regcomp(&res.version_re, VERSION_RE, 0))
338     xbt_die(".so regexp did not compile");
339
340   std::vector<simgrid::mc::VmMap> const& maps = this->memory_map_;
341
342   const char* current_name = NULL;
343
344   for (size_t i=0; i < maps.size(); i++) {
345     simgrid::mc::VmMap const& reg = maps[i];
346     const char* pathname = maps[i].pathname.c_str();
347
348     // Nothing to do
349     if (maps[i].pathname.empty()) {
350       current_name = NULL;
351       continue;
352     }
353
354     // [stack], [vvar], [vsyscall], [vdso] ...
355     if (pathname[0] == '[') {
356       if ((reg.prot & PROT_WRITE) && !memcmp(pathname, "[stack]", 7)) {
357         this->maestro_stack_start_ = remote(reg.start_addr);
358         this->maestro_stack_end_ = remote(reg.end_addr);
359       }
360       current_name = NULL;
361       continue;
362     }
363
364     if (current_name && strcmp(current_name, pathname)==0)
365       continue;
366
367     current_name = pathname;
368     if (!(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
369       continue;
370
371     const bool is_executable = !i;
372     char* libname = NULL;
373     if (!is_executable) {
374       libname = MC_get_lib_name(pathname, &res);
375       if(!libname)
376         continue;
377       if (MC_is_filtered_lib(libname)) {
378         free(libname);
379         continue;
380       }
381     }
382
383     mc_object_info_t info =
384       MC_find_object_info(this->memory_map_, pathname, is_executable);
385     this->object_infos = (mc_object_info_t*) realloc(this->object_infos,
386       (this->object_infos_size+1) * sizeof(mc_object_info_t));
387     this->object_infos[this->object_infos_size] = info;
388     this->object_infos_size++;
389     if (is_executable)
390       this->binary_info = info;
391     else if (libname && MC_is_simgrid_lib(libname))
392       this->libsimgrid_info = info;
393     free(libname);
394   }
395
396   regfree(&res.so_re);
397   regfree(&res.version_re);
398
399   // Resolve time (including accross differents objects):
400   for (size_t i=0; i!=this->object_infos_size; ++i)
401     MC_post_process_object_info(this, this->object_infos[i]);
402
403   xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
404   xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
405
406   XBT_DEBUG("Get debug information done !");
407 }
408
409 mc_object_info_t Process::find_object_info(remote_ptr<void> addr) const
410 {
411   size_t i;
412   for (i = 0; i != this->object_infos_size; ++i) {
413     if (addr.address() >= (std::uint64_t)this->object_infos[i]->start
414         && addr.address() <= (std::uint64_t)this->object_infos[i]->end) {
415       return this->object_infos[i];
416     }
417   }
418   return NULL;
419 }
420
421 mc_object_info_t Process::find_object_info_exec(remote_ptr<void> addr) const
422 {
423   size_t i;
424   for (i = 0; i != this->object_infos_size; ++i) {
425     if (addr.address() >= (std::uint64_t)this->object_infos[i]->start_exec
426         && addr.address() <= (std::uint64_t)this->object_infos[i]->end_exec) {
427       return this->object_infos[i];
428     }
429   }
430   return NULL;
431 }
432
433 mc_object_info_t Process::find_object_info_rw(remote_ptr<void> addr) const
434 {
435   size_t i;
436   for (i = 0; i != this->object_infos_size; ++i) {
437     if (addr.address() >= (std::uint64_t)this->object_infos[i]->start_rw
438         && addr.address() <= (std::uint64_t)this->object_infos[i]->end_rw) {
439       return this->object_infos[i];
440     }
441   }
442   return NULL;
443 }
444
445 dw_frame_t Process::find_function(remote_ptr<void> ip) const
446 {
447   mc_object_info_t info = this->find_object_info_exec(ip);
448   if (info == NULL)
449     return NULL;
450   else
451     return MC_file_object_info_find_function(info, (void*) ip.address());
452 }
453
454 /** Find (one occurence of) the named variable definition
455  */
456 dw_variable_t Process::find_variable(const char* name) const
457 {
458   const size_t n = this->object_infos_size;
459   size_t i;
460
461   // First lookup the variable in the executable shared object.
462   // A global variable used directly by the executable code from a library
463   // is reinstanciated in the executable memory .data/.bss.
464   // We need to look up the variable in the execvutable first.
465   if (this->binary_info) {
466     mc_object_info_t info = this->binary_info;
467     dw_variable_t var = MC_file_object_info_find_variable_by_name(info, name);
468     if (var)
469       return var;
470   }
471
472   for (i=0; i!=n; ++i) {
473     mc_object_info_t info = this->object_infos[i];
474     dw_variable_t var = MC_file_object_info_find_variable_by_name(info, name);
475     if (var)
476       return var;
477   }
478
479   return NULL;
480 }
481
482 void Process::read_variable(const char* name, void* target, size_t size) const
483 {
484   dw_variable_t var = this->find_variable(name);
485   if (!var->address)
486     xbt_die("No simple location for this variable");
487   if (!var->type->full_type)
488     xbt_die("Partial type for %s, cannot check size", name);
489   if ((size_t) var->type->full_type->byte_size != size)
490     xbt_die("Unexpected size for %s (expected %zi, was %zi)",
491       name, size, (size_t) var->type->full_type->byte_size);
492   this->read_bytes(target, size, remote(var->address));
493 }
494
495 char* Process::read_string(remote_ptr<void> address) const
496 {
497   if (!address)
498     return NULL;
499   if (this->is_self())
500     return strdup((char*) address.address());
501
502   off_t len = 128;
503   char* res = (char*) malloc(len);
504   off_t off = 0;
505
506   while (1) {
507     ssize_t c = pread(this->memory_file, res + off, len - off, (off_t) address.address() + off);
508     if (c == -1) {
509       if (errno == EINTR)
510         continue;
511       else
512         xbt_die("Could not read from from remote process");
513     }
514     if (c==0)
515       xbt_die("Could not read string from remote process");
516
517     void* p = memchr(res + off, '\0', c);
518     if (p)
519       return res;
520
521     off += c;
522     if (off == len) {
523       len *= 2;
524       res = (char*) realloc(res, len);
525     }
526   }
527 }
528
529 const void *Process::read_bytes(void* buffer, std::size_t size,
530   remote_ptr<void> address, int process_index,
531   AddressSpace::ReadMode mode) const
532 {
533   if (process_index != simgrid::mc::ProcessIndexDisabled) {
534     mc_object_info_t info = this->find_object_info_rw((void*)address.address());
535     // Segment overlap is not handled.
536     if (MC_object_info_is_privatized(info)) {
537       if (process_index < 0)
538         xbt_die("Missing process index");
539       if (process_index >= (int) MC_smpi_process_count())
540         xbt_die("Invalid process index");
541
542       // Read smpi_privatisation_regions from MCed:
543       smpi_privatisation_region_t remote_smpi_privatisation_regions =
544         mc_model_checker->process().read_variable<smpi_privatisation_region_t>(
545           "smpi_privatisation_regions");
546
547       s_smpi_privatisation_region_t privatisation_region =
548         mc_model_checker->process().read<s_smpi_privatisation_region_t>(
549           remote(remote_smpi_privatisation_regions + process_index));
550
551       // Address translation in the privaization segment:
552       size_t offset = address.address() - (std::uint64_t)info->start_rw;
553       address = remote((char*)privatisation_region.address + offset);
554     }
555   }
556
557   if (this->is_self()) {
558     if (mode == simgrid::mc::AddressSpace::Lazy)
559       return (void*)address.address();
560     else {
561       memcpy(buffer, (void*)address.address(), size);
562       return buffer;
563     }
564   } else {
565     if (pread_whole(this->memory_file, buffer, size, (off_t) address.address()) < 0)
566       xbt_die("Read from process %lli failed", (long long) this->pid_);
567     return buffer;
568   }
569 }
570
571 /** Write data to a process memory
572  *
573  *  @param process the process
574  *  @param local   local memory address (source)
575  *  @param remote  target process memory address (target)
576  *  @param len     data size
577  */
578 void Process::write_bytes(const void* buffer, size_t len, remote_ptr<void> address)
579 {
580   if (this->is_self()) {
581     memcpy((void*)address.address(), buffer, len);
582   } else {
583     if (pwrite_whole(this->memory_file, buffer, len, address.address()) < 0)
584       xbt_die("Write to process %lli failed", (long long) this->pid_);
585   }
586 }
587
588 void Process::clear_bytes(remote_ptr<void> address, size_t len)
589 {
590   if (this->is_self()) {
591     memset((void*)address.address(), 0, len);
592   } else {
593     pthread_once(&zero_buffer_flag, MC_zero_buffer_init);
594     while (len) {
595       size_t s = len > zero_buffer_size ? zero_buffer_size : len;
596       this->write_bytes(zero_buffer, s, address);
597       address = remote((char*) address.address() + s);
598       len -= s;
599     }
600   }
601 }
602
603 void Process::ignore_region(std::uint64_t addr, std::size_t size)
604 {
605   IgnoredRegion region;
606   region.addr = addr;
607   region.size = size;
608
609   if (ignored_regions_.empty()) {
610     ignored_regions_.push_back(region);
611     return;
612   }
613
614   unsigned int cursor = 0;
615   IgnoredRegion* current_region = nullptr;
616
617   int start = 0;
618   int end = ignored_regions_.size() - 1;
619   while (start <= end) {
620     cursor = (start + end) / 2;
621     current_region = &ignored_regions_[cursor];
622     if (current_region->addr == addr) {
623       if (current_region->size == size)
624         return;
625       else if (current_region->size < size)
626         start = cursor + 1;
627       else
628         end = cursor - 1;
629     } else if (current_region->addr < addr)
630       start = cursor + 1;
631     else
632       end = cursor - 1;
633   }
634
635   std::size_t position;
636   if (current_region->addr == addr) {
637     if (current_region->size < size) {
638       position = cursor + 1;
639     } else {
640       position = cursor;
641     }
642   } else if (current_region->addr < addr) {
643     position = cursor + 1;
644   } else {
645     position = cursor;
646   }
647   ignored_regions_.insert(
648     ignored_regions_.begin() + position, region);
649 }
650
651 }
652 }