X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/8847b375a11af83a841c0964292a2fe9ee9a0fff..39d3a0153b242aa016bdc528c9268a958bcd98d2:/src/mc/mc_checkpoint.c

diff --git a/src/mc/mc_checkpoint.c b/src/mc/mc_checkpoint.c
index a89b14a20e..b21f190862 100644
--- a/src/mc/mc_checkpoint.c
+++ b/src/mc/mc_checkpoint.c
@@ -1,757 +1,761 @@
-/* Copyright (c) 2008-2013 Da SimGrid Team. All rights reserved.            */
+/* Copyright (c) 2008-2014. The SimGrid Team.
+ * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
-#include <libgen.h>
+#define _GNU_SOURCE
+#define UNW_LOCAL_ONLY
+
+#include <unistd.h>
+
+#include <string.h>
+#include <link.h>
+#include <dirent.h>
+
+#include "internal_config.h"
 #include "mc_private.h"
 #include "xbt/module.h"
+#include <xbt/mmalloc.h>
+#include "../smpi/private.h"
+#include <alloca.h>
+
+#include "xbt/mmalloc/mmprivate.h"
 
 #include "../simix/smx_private.h"
 
+#define UNW_LOCAL_ONLY
 #include <libunwind.h>
+#include <libelf.h>
+
+#include "mc_private.h"
+#include <mc/mc.h>
+
+#include "mc_mmu.h"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_checkpoint, mc,
                                 "Logging specific to mc_checkpoint");
 
-void *start_text_libsimgrid;
-void *start_plt_libsimgrid, *end_plt_libsimgrid;
-void *start_got_plt_libsimgrid, *end_got_plt_libsimgrid;
-void *start_plt_binary, *end_plt_binary;
-void *start_got_plt_binary, *end_got_plt_binary;
 char *libsimgrid_path;
-void *start_data_libsimgrid, *start_bss_libsimgrid;
-void *start_data_binary, *start_bss_binary;
-void *start_text_binary;
 
-static mc_mem_region_t MC_region_new(int type, void *start_addr, size_t size);
-static void MC_region_restore(mc_mem_region_t reg);
-static void MC_region_destroy(mc_mem_region_t reg);
+/************************************  Free functions **************************************/
+/*****************************************************************************************/
 
-static void MC_snapshot_add_region(mc_snapshot_t snapshot, int type, void *start_addr, size_t size);
+static void MC_snapshot_stack_free(mc_snapshot_stack_t s)
+{
+  if (s) {
+    xbt_dynar_free(&(s->local_variables));
+    xbt_dynar_free(&(s->stack_frames));
+    xbt_free(s);
+  }
+}
 
-static void add_value(xbt_dynar_t *list, const char *type, unsigned long int val);
-static xbt_dynar_t take_snapshot_stacks(mc_snapshot_t *s, void *heap);
-static xbt_strbuff_t get_local_variables_values(void *stack_context, void *heap);
-static void print_local_variables_values(xbt_dynar_t all_variables);
-static void *get_stack_pointer(void *stack_context, void *heap);
+static void MC_snapshot_stack_free_voidp(void *s)
+{
+  MC_snapshot_stack_free((mc_snapshot_stack_t) * (void **) s);
+}
 
-static void snapshot_stack_free(mc_snapshot_stack_t s);
-static xbt_dynar_t take_snapshot_ignore(void);
+static void local_variable_free(local_variable_t v)
+{
+  xbt_free(v->name);
+  xbt_free(v);
+}
 
-static void get_hash_global(char *snapshot_hash, void *data1, void *data2);
-static void get_hash_local(char *snapshot_hash, xbt_dynar_t stacks);
+static void local_variable_free_voidp(void *v)
+{
+  local_variable_free((local_variable_t) * (void **) v);
+}
+
+void MC_region_destroy(mc_mem_region_t reg)
+{
+  if (!reg)
+    return;
+
+  //munmap(reg->data, reg->size);
+  xbt_free(reg->data);
+  if (reg->page_numbers) {
+    mc_free_page_snapshot_region(reg->page_numbers, mc_page_count(reg->size));
+  }
+  xbt_free(reg);
+}
 
-static mc_mem_region_t MC_region_new(int type, void *start_addr, size_t size)
+void MC_free_snapshot(mc_snapshot_t snapshot)
 {
-  mc_mem_region_t new_reg = xbt_new0(s_mc_mem_region_t, 1);
+  unsigned int i;
+  for (i = 0; i < NB_REGIONS; i++) {
+    MC_region_destroy(snapshot->regions[i]);
+  }
+
+  xbt_free(snapshot->stack_sizes);
+  xbt_dynar_free(&(snapshot->stacks));
+  xbt_dynar_free(&(snapshot->to_ignore));
+  xbt_dynar_free(&snapshot->ignored_data);
+
+  if (snapshot->privatization_regions) {
+    size_t n = xbt_dynar_length(snapshot->enabled_processes);
+    for (i = 0; i != n; ++i) {
+      MC_region_destroy(snapshot->privatization_regions[i]);
+    }
+    xbt_free(snapshot->privatization_regions);
+  }
+
+  xbt_free(snapshot);
+}
+
+/*******************************  Snapshot regions ********************************/
+/*********************************************************************************/
+
+static mc_mem_region_t mc_region_new_dense(int type, void *start_addr, void* permanent_addr, size_t size, mc_mem_region_t ref_reg)
+{
+  mc_mem_region_t new_reg = xbt_new(s_mc_mem_region_t, 1);
   new_reg->start_addr = start_addr;
+  new_reg->permanent_addr = permanent_addr;
+  new_reg->data = NULL;
   new_reg->size = size;
-  new_reg->data = xbt_malloc0(size);
-  memcpy(new_reg->data, start_addr, size);
-
-  XBT_DEBUG("New region : type : %d, data : %p (real addr %p), size : %zu", type, new_reg->data, start_addr, size);
-  
+  new_reg->page_numbers = NULL;
+  new_reg->data = xbt_malloc(size);
+  memcpy(new_reg->data, permanent_addr, size);
+  XBT_DEBUG("New region : type : %d, data : %p (real addr %p), size : %zu",
+            type, new_reg->data, permanent_addr, size);
   return new_reg;
+
+}
+
+/** @brief Take a snapshot of a given region
+ *
+ * @param type
+ * @param start_addr   Address of the region in the simulated process
+ * @param permanent_addr Permanent address of this data (for privatized variables, this is the virtual address of the privatized mapping)
+ * @param size         Size of the data*
+ * @param ref_reg      Reference corresponding region
+ */
+static mc_mem_region_t MC_region_new(int type, void *start_addr, void* permanent_addr, size_t size, mc_mem_region_t ref_reg)
+{
+  if (_sg_mc_sparse_checkpoint) {
+    return mc_region_new_sparse(type, start_addr, permanent_addr, size, ref_reg);
+  } else  {
+    return mc_region_new_dense(type, start_addr, permanent_addr, size, ref_reg);
+  }
 }
 
-static void MC_region_restore(mc_mem_region_t reg)
+/** @brief Restore a region from a snapshot
+ *
+ *  If we are using per page snapshots, it is possible to use the reference
+ *  region in order to do an incremental restoration of the region: the
+ *  softclean pages which are shared between the two snapshots do not need
+ *  to be restored.
+ *
+ *  @param reg     Target region
+ *  @param reg_reg Current region (if not NULL), used for lazy per page restoration
+ */
+static void MC_region_restore(mc_mem_region_t reg, mc_mem_region_t ref_reg)
 {
   /*FIXME: check if start_addr is still mapped, if it is not, then map it
     before copying the data */
- 
-  memcpy(reg->start_addr, reg->data, reg->size);
- 
+  if (!reg->page_numbers) {
+    memcpy(reg->permanent_addr, reg->data, reg->size);
+  } else {
+    mc_region_restore_sparse(reg, ref_reg);
+  }
   return;
 }
 
-static void MC_region_destroy(mc_mem_region_t reg)
-{
-  xbt_free(reg->data);
-  xbt_free(reg);
-}
+static void MC_snapshot_add_region(mc_snapshot_t snapshot, int type,
+                                   void *start_addr, void* permanent_addr, size_t size)
 
-static void MC_snapshot_add_region(mc_snapshot_t snapshot, int type, void *start_addr, size_t size)
 {
-  mc_mem_region_t new_reg = MC_region_new(type, start_addr, size);
+  mc_mem_region_t ref_reg =
+    mc_model_checker->parent_snapshot ? mc_model_checker->parent_snapshot->regions[type] : NULL;
+  mc_mem_region_t new_reg = MC_region_new(type, start_addr, permanent_addr, size, ref_reg);
   snapshot->regions[type] = new_reg;
   return;
-} 
+}
+
+static void MC_get_memory_regions(mc_snapshot_t snapshot)
+{
 
-void MC_init_memory_map_info(){
+  void *start_heap = std_heap->base;
+  void *end_heap = std_heap->breakval;
+  MC_snapshot_add_region(snapshot, 0, start_heap, start_heap,
+                         (char *) end_heap - (char *) start_heap);
+  snapshot->heap_bytes_used = mmalloc_get_bytes_used(std_heap);
+  snapshot->privatization_regions = NULL;
+
+  MC_snapshot_add_region(snapshot, 1,
+      mc_libsimgrid_info->start_rw, mc_libsimgrid_info->start_rw,
+      mc_libsimgrid_info->end_rw - mc_libsimgrid_info->start_rw);
+
+#ifdef HAVE_SMPI
+  size_t i;
+  if (smpi_privatize_global_variables && smpi_process_count()) {
+    // Snapshot the global variable of the application separately for each
+    // simulated process:
+    snapshot->privatization_regions =
+      xbt_new(mc_mem_region_t, smpi_process_count());
+    for (i = 0; i < smpi_process_count(); i++) {
+      mc_mem_region_t ref_reg =
+        mc_model_checker->parent_snapshot ? mc_model_checker->parent_snapshot->privatization_regions[i] : NULL;
+      snapshot->privatization_regions[i] =
+        MC_region_new(-1, mc_binary_info->start_rw, smpi_privatisation_regions[i].address, size_data_exe, ref_reg);
+    }
+    snapshot->privatization_index = smpi_loaded_page;
+    snapshot->regions[2] = NULL;
+  } else
+#endif
+  {
+    MC_snapshot_add_region(snapshot, 2,
+                           mc_binary_info->start_rw, mc_binary_info->start_rw,
+                           mc_binary_info->end_rw - mc_binary_info->start_rw);
+    snapshot->privatization_regions = NULL;
+    snapshot->privatization_index = -1;
+  }
+}
 
-  int raw_mem_set = (mmalloc_get_current_heap() == raw_heap);
+/** @brief Finds the range of the different memory segments and binary paths */
+void MC_init_memory_map_info()
+{
 
-  MC_SET_RAW_MEM;
-  
   unsigned int i = 0;
   s_map_region_t reg;
-  memory_map_t maps = get_memory_map();
+  memory_map_t maps = MC_get_memory_map();
+
+  maestro_stack_start = NULL;
+  maestro_stack_end = NULL;
+  libsimgrid_path = NULL;
 
   while (i < maps->mapsize) {
     reg = maps->regions[i];
-    if ((reg.prot & PROT_WRITE)){
-      if (maps->regions[i].pathname != NULL){
-        if (!memcmp(basename(maps->regions[i].pathname), "libsimgrid", 10)){
-          start_data_libsimgrid = reg.start_addr;
-          i++;
-          reg = maps->regions[i];
-          if(reg.pathname == NULL && (reg.prot & PROT_WRITE) && i < maps->mapsize)
-            start_bss_libsimgrid = reg.start_addr;
-        }else if (!memcmp(basename(maps->regions[i].pathname), basename(xbt_binary_name), strlen(basename(xbt_binary_name)))){
-          start_data_binary = reg.start_addr;
-          i++;
-          reg = maps->regions[i];
-          if(reg.pathname == NULL && (reg.prot & PROT_WRITE) && reg.start_addr != std_heap && reg.start_addr != raw_heap && i < maps->mapsize){
-            start_bss_binary = reg.start_addr;
-            i++;
-          }
-        }else if(!memcmp(maps->regions[i].pathname, "[stack]", 7)){
-          maestro_stack_start = reg.start_addr;
-          maestro_stack_end = reg.end_addr;
-          i++;
-        }
-      }
-    }else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)){
-      if (maps->regions[i].pathname != NULL){
-        if (!memcmp(basename(maps->regions[i].pathname), "libsimgrid", 10)){
-          start_text_libsimgrid = reg.start_addr;
-          libsimgrid_path = strdup(maps->regions[i].pathname);
-        }else if (!memcmp(basename(maps->regions[i].pathname), basename(xbt_binary_name), strlen(basename(xbt_binary_name)))){
-          start_text_binary = reg.start_addr;
-        }
-      }
+    if (maps->regions[i].pathname == NULL) {
+      // Nothing to do
+    } else if ((reg.prot & PROT_WRITE)
+               && !memcmp(maps->regions[i].pathname, "[stack]", 7)) {
+      maestro_stack_start = reg.start_addr;
+      maestro_stack_end = reg.end_addr;
+    } else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)
+               && !memcmp(basename(maps->regions[i].pathname), "libsimgrid",
+                          10)) {
+      if (libsimgrid_path == NULL)
+        libsimgrid_path = strdup(maps->regions[i].pathname);
     }
     i++;
   }
-  
-  free_memory_map(maps);
 
-  MC_UNSET_RAW_MEM;
+  xbt_assert(maestro_stack_start, "maestro_stack_start");
+  xbt_assert(maestro_stack_end, "maestro_stack_end");
+  xbt_assert(libsimgrid_path, "libsimgrid_path&");
 
-  if(raw_mem_set)
-    MC_SET_RAW_MEM;
+  MC_free_memory_map(maps);
 
 }
 
-mc_snapshot_t MC_take_snapshot()
+/** \brief Fills the position of the segments (executable, read-only, read/write).
+ *
+ * TODO, use dl_iterate_phdr to be more robust
+ * */
+void MC_find_object_address(memory_map_t maps, mc_object_info_t result)
 {
-  int raw_mem = (mmalloc_get_current_heap() == raw_heap);
-  
-  MC_SET_RAW_MEM;
-
-  mc_snapshot_t snapshot = xbt_new0(s_mc_snapshot_t, 1);
-  snapshot->nb_processes = xbt_swag_size(simix_global->process_list);
 
   unsigned int i = 0;
   s_map_region_t reg;
-  memory_map_t maps = get_memory_map();
-  void *heap = NULL;
-  size_t size = 0;
-  void *start = NULL;
-
-  /* Save the std heap and the writable mapped pages of libsimgrid */
+  const char *name = basename(result->file_name);
   while (i < maps->mapsize) {
     reg = maps->regions[i];
-    if ((reg.prot & PROT_WRITE)){
-      if (maps->regions[i].pathname == NULL){
-        if (reg.start_addr == std_heap){ // only save the std heap (and not the raw one)
-          MC_snapshot_add_region(snapshot, 0, reg.start_addr, (char*)reg.end_addr - (char*)reg.start_addr);
-          snapshot->heap_bytes_used = mmalloc_get_bytes_used(std_heap);
-          heap = snapshot->regions[0]->data;
-        }
-        i++;
-      } else{ 
-        if (!memcmp(basename(maps->regions[i].pathname), "libsimgrid", 10)){
-          size = (char*)reg.end_addr - (char*)reg.start_addr;
-          start = reg.start_addr;
-          i++;
-          reg = maps->regions[i];
-          if(reg.pathname == NULL && (reg.prot & PROT_WRITE) && i < maps->mapsize){
-            size += (char*)reg.end_addr - (char*)reg.start_addr;
-            reg = maps->regions[i];
-            i++;
-          }
-          MC_snapshot_add_region(snapshot, 1, start, size);
-        }else if(!memcmp(maps->regions[i].pathname, "[stack]", 7)){
-          maestro_stack_start = reg.start_addr;
-          maestro_stack_end = reg.end_addr;
-          i++;
-        } else if (!memcmp(basename(maps->regions[i].pathname), basename(xbt_binary_name), strlen(basename(xbt_binary_name)))){
-          size = (char*)reg.end_addr - (char*)reg.start_addr;
-          start = reg.start_addr;
-          i++;
-          reg = maps->regions[i];
-          if(reg.pathname == NULL && (reg.prot & PROT_WRITE) && reg.start_addr != std_heap && reg.start_addr != raw_heap && i < maps->mapsize){
-            size += (char*)reg.end_addr - (char*)reg.start_addr;
-            reg = maps->regions[i];
-            i++;
-          }
-          MC_snapshot_add_region(snapshot, 2, start, size);
-        }else{
-          i++;
-        }
+    if (maps->regions[i].pathname == NULL
+        || strcmp(basename(maps->regions[i].pathname), name)) {
+      // Nothing to do
+    } else if ((reg.prot & PROT_WRITE)) {
+      xbt_assert(!result->start_rw,
+                 "Multiple read-write segments for %s, not supported",
+                 maps->regions[i].pathname);
+      result->start_rw = reg.start_addr;
+      result->end_rw = reg.end_addr;
+      // .bss is usually after the .data:
+      s_map_region_t *next = &(maps->regions[i + 1]);
+      if (next->pathname == NULL && (next->prot & PROT_WRITE)
+          && next->start_addr == reg.end_addr) {
+        result->end_rw = maps->regions[i + 1].end_addr;
       }
-    }else{
-      i++;
+    } else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)) {
+      xbt_assert(!result->start_exec,
+                 "Multiple executable segments for %s, not supported",
+                 maps->regions[i].pathname);
+      result->start_exec = reg.start_addr;
+      result->end_exec = reg.end_addr;
+    } else if ((reg.prot & PROT_READ) && !(reg.prot & PROT_EXEC)) {
+      xbt_assert(!result->start_ro,
+                 "Multiple read only segments for %s, not supported",
+                 maps->regions[i].pathname);
+      result->start_ro = reg.start_addr;
+      result->end_ro = reg.end_addr;
     }
+    i++;
   }
 
-  snapshot->to_ignore = take_snapshot_ignore();
+  xbt_assert(result->file_name);
+  xbt_assert(result->start_rw);
+  xbt_assert(result->start_exec);
+}
 
-  if(_sg_mc_visited > 0 || strcmp(_sg_mc_property_file,"")){
-    snapshot->stacks = take_snapshot_stacks(&snapshot, heap);
-    get_hash_global(snapshot->hash_global, snapshot->regions[1]->data, snapshot->regions[2]->data);
-    get_hash_local(snapshot->hash_local, snapshot->stacks);
-  }
+/************************************* Take Snapshot ************************************/
+/****************************************************************************************/
+
+/** \brief Checks whether the variable is in scope for a given IP.
+ *
+ *  A variable may be defined only from a given value of IP.
+ *
+ *  \param var   Variable description
+ *  \param frame Scope description
+ *  \param ip    Instruction pointer
+ *  \return      true if the variable is valid
+ * */
+static bool mc_valid_variable(dw_variable_t var, dw_frame_t scope,
+                              const void *ip)
+{
+  // The variable is not yet valid:
+  if ((const void *) ((const char *) scope->low_pc + var->start_scope) > ip)
+    return false;
+  else
+    return true;
+}
 
-  free_memory_map(maps);
+static void mc_fill_local_variables_values(mc_stack_frame_t stack_frame,
+                                           dw_frame_t scope, int process_index, xbt_dynar_t result)
+{
+  void *ip = (void *) stack_frame->ip;
+  if (ip < scope->low_pc || ip >= scope->high_pc)
+    return;
 
-  MC_UNSET_RAW_MEM;
+  unsigned cursor = 0;
+  dw_variable_t current_variable;
+  xbt_dynar_foreach(scope->variables, cursor, current_variable) {
 
-  if(raw_mem)
-    MC_SET_RAW_MEM;
+    if (!mc_valid_variable(current_variable, scope, (void *) stack_frame->ip))
+      continue;
 
-  return snapshot;
+    int region_type;
+    if ((long) stack_frame->ip > (long) mc_libsimgrid_info->start_exec)
+      region_type = 1;
+    else
+      region_type = 2;
+
+    local_variable_t new_var = xbt_new0(s_local_variable_t, 1);
+    new_var->subprogram = stack_frame->frame;
+    new_var->ip = stack_frame->ip;
+    new_var->name = xbt_strdup(current_variable->name);
+    new_var->type = current_variable->type;
+    new_var->region = region_type;
+
+    if (current_variable->address != NULL) {
+      new_var->address = current_variable->address;
+    } else if (current_variable->locations.size != 0) {
+      s_mc_location_t location;
+      mc_dwarf_resolve_locations(&location, &current_variable->locations,
+                                              current_variable->object_info,
+                                              &(stack_frame->unw_cursor),
+                                              (void *) stack_frame->frame_base,
+                                              NULL, process_index);
+
+      switch(mc_get_location_type(&location)) {
+      case MC_LOCATION_TYPE_ADDRESS:
+        new_var->address = location.memory_location;
+        break;
+      case MC_LOCATION_TYPE_REGISTER:
+      default:
+        xbt_die("Cannot handle non-address variable");
+      }
 
-}
+    } else {
+      xbt_die("No address");
+    }
 
-void MC_restore_snapshot(mc_snapshot_t snapshot)
-{
-  unsigned int i;
-  for(i=0; i < NB_REGIONS; i++){
-    MC_region_restore(snapshot->regions[i]);
+    xbt_dynar_push(result, &new_var);
   }
 
+  // Recursive processing of nested scopes:
+  dw_frame_t nested_scope = NULL;
+  xbt_dynar_foreach(scope->scopes, cursor, nested_scope) {
+    mc_fill_local_variables_values(stack_frame, nested_scope, process_index, result);
+  }
 }
 
-void MC_free_snapshot(mc_snapshot_t snapshot)
+static xbt_dynar_t MC_get_local_variables_values(xbt_dynar_t stack_frames, int process_index)
 {
-  unsigned int i;
-  for(i=0; i < NB_REGIONS; i++)
-    MC_region_destroy(snapshot->regions[i]);
 
-  xbt_dynar_free(&(snapshot->stacks));
-  xbt_dynar_free(&(snapshot->to_ignore));
-  xbt_free(snapshot);
+  unsigned cursor1 = 0;
+  mc_stack_frame_t stack_frame;
+  xbt_dynar_t variables =
+      xbt_dynar_new(sizeof(local_variable_t), local_variable_free_voidp);
+
+  xbt_dynar_foreach(stack_frames, cursor1, stack_frame) {
+    mc_fill_local_variables_values(stack_frame, stack_frame->frame, process_index, variables);
+  }
+
+  return variables;
 }
 
+static void MC_stack_frame_free_voipd(void *s)
+{
+  mc_stack_frame_t stack_frame = *(mc_stack_frame_t *) s;
+  if (stack_frame) {
+    xbt_free(stack_frame->frame_name);
+    xbt_free(stack_frame);
+  }
+}
 
-void get_libsimgrid_plt_section(){
+static xbt_dynar_t MC_unwind_stack_frames(void *stack_context)
+{
+  xbt_dynar_t result =
+      xbt_dynar_new(sizeof(mc_stack_frame_t), MC_stack_frame_free_voipd);
 
-  FILE *fp;
-  char *line = NULL;            /* Temporal storage for each line that is readed */
-  ssize_t read;                 /* Number of bytes readed */
-  size_t n = 0;                 /* Amount of bytes to read by xbt_getline */
+  unw_cursor_t c;
 
-  char *lfields[7];
-  int i, plt_found = 0;
-  unsigned long int size, offset;
+  // TODO, check condition check (unw_init_local==0 means end of frame)
+  if (unw_init_local(&c, (unw_context_t *) stack_context) != 0) {
 
-  char *command = bprintf("objdump --section-headers %s", libsimgrid_path);
+    xbt_die("Could not initialize stack unwinding");
 
-  fp = popen(command, "r");
+  } else
+    while (1) {
 
-  if(fp == NULL){
-    perror("popen failed");
-    xbt_abort();
-  }
+      mc_stack_frame_t stack_frame = xbt_new(s_mc_stack_frame_t, 1);
+      xbt_dynar_push(result, &stack_frame);
 
-  while ((read = xbt_getline(&line, &n, fp)) != -1 && plt_found != 2) {
+      stack_frame->unw_cursor = c;
 
-    if(n == 0)
-      continue;
+      unw_word_t ip, sp;
 
-    /* Wipeout the new line character */
-    line[read - 1] = '\0';
+      unw_get_reg(&c, UNW_REG_IP, &ip);
+      unw_get_reg(&c, UNW_REG_SP, &sp);
 
-    lfields[0] = strtok(line, " ");
+      stack_frame->ip = ip;
+      stack_frame->sp = sp;
 
-    if(lfields[0] == NULL)
-      continue;
+      // TODO, use real addresses in frame_t instead of fixing it here
 
-    if(strcmp(lfields[0], "Sections:") == 0 || strcmp(lfields[0], "Idx") == 0 || strncmp(lfields[0], libsimgrid_path, strlen(libsimgrid_path)) == 0)
-      continue;
+      dw_frame_t frame = MC_find_function_by_ip((void *) ip);
+      stack_frame->frame = frame;
 
-    for (i = 1; i < 7 && lfields[i - 1] != NULL; i++) {
-      lfields[i] = strtok(NULL, " ");
-    }
+      if (frame) {
+        stack_frame->frame_name = xbt_strdup(frame->name);
+        stack_frame->frame_base =
+            (unw_word_t) mc_find_frame_base(frame, frame->object_info, &c);
+      } else {
+        stack_frame->frame_base = 0;
+        stack_frame->frame_name = NULL;
+      }
 
-    if(i>=6){
-      if(strcmp(lfields[1], ".plt") == 0){
-        size = strtoul(lfields[2], NULL, 16);
-        offset = strtoul(lfields[5], NULL, 16);
-        start_plt_libsimgrid = (char *)start_text_libsimgrid + offset;
-        end_plt_libsimgrid = (char *)start_plt_libsimgrid + size;
-        plt_found++;
-      }else if(strcmp(lfields[1], ".got.plt") == 0){
-        size = strtoul(lfields[2], NULL, 16);
-        offset = strtoul(lfields[5], NULL, 16);
-        start_got_plt_libsimgrid = (char *)start_text_libsimgrid + offset;
-        end_got_plt_libsimgrid = (char *)start_got_plt_libsimgrid + size;
-        plt_found++;
-       }
+      /* Stop before context switch with maestro */
+      if (frame != NULL && frame->name != NULL
+          && !strcmp(frame->name, "smx_ctx_sysv_wrapper"))
+        break;
 
+      int ret = ret = unw_step(&c);
+      if (ret == 0) {
+        xbt_die("Unexpected end of stack.");
+      } else if (ret < 0) {
+        xbt_die("Error while unwinding stack.");
+      }
     }
-    
-  }
 
-  xbt_free(command);
-  xbt_free(line);
-  pclose(fp);
+  if (xbt_dynar_length(result) == 0) {
+    XBT_INFO("unw_init_local failed");
+    xbt_abort();
+  }
 
-}
+  return result;
+};
 
-void get_binary_plt_section(){
+static xbt_dynar_t MC_take_snapshot_stacks(mc_snapshot_t * snapshot)
+{
 
-  FILE *fp;
-  char *line = NULL;            /* Temporal storage for each line that is readed */
-  ssize_t read;                 /* Number of bytes readed */
-  size_t n = 0;                 /* Amount of bytes to read by xbt_getline */
+  xbt_dynar_t res =
+      xbt_dynar_new(sizeof(s_mc_snapshot_stack_t),
+                    MC_snapshot_stack_free_voidp);
 
-  char *lfields[7];
-  int i, plt_found = 0;
-  unsigned long int size;
+  unsigned int cursor = 0;
+  stack_region_t current_stack;
 
-  char *command = bprintf( "objdump --section-headers %s", xbt_binary_name);
+  xbt_dynar_foreach(stacks_areas, cursor, current_stack) {
+    mc_snapshot_stack_t st = xbt_new(s_mc_snapshot_stack_t, 1);
+    st->stack_frames = MC_unwind_stack_frames(current_stack->context);
+    st->local_variables = MC_get_local_variables_values(st->stack_frames, current_stack->process_index);
+    st->process_index = current_stack->process_index;
 
-  fp = popen(command, "r");
+    unw_word_t sp = xbt_dynar_get_as(st->stack_frames, 0, mc_stack_frame_t)->sp;
 
-  if(fp == NULL){
-    perror("popen failed");
-    xbt_abort();
+    xbt_dynar_push(res, &st);
+    (*snapshot)->stack_sizes =
+        xbt_realloc((*snapshot)->stack_sizes, (cursor + 1) * sizeof(size_t));
+    (*snapshot)->stack_sizes[cursor] =
+      (char*) current_stack->address + current_stack->size - (char*) sp;
   }
 
-  while ((read = xbt_getline(&line, &n, fp)) != -1 && plt_found != 2) {
+  return res;
 
-    if(n == 0)
-      continue;
+}
 
-    /* Wipeout the new line character */
-    line[read - 1] = '\0';
+static xbt_dynar_t MC_take_snapshot_ignore()
+{
 
-    lfields[0] = strtok(line, " ");
+  if (mc_heap_comparison_ignore == NULL)
+    return NULL;
 
-    if(lfields[0] == NULL)
-      continue;
+  xbt_dynar_t cpy =
+      xbt_dynar_new(sizeof(mc_heap_ignore_region_t),
+                    heap_ignore_region_free_voidp);
 
-    if(strcmp(lfields[0], "Sections:") == 0 || strcmp(lfields[0], "Idx") == 0 || strncmp(lfields[0], basename(xbt_binary_name), strlen(xbt_binary_name)) == 0)
-      continue;
-
-    for (i = 1; i < 7 && lfields[i - 1] != NULL; i++) {
-      lfields[i] = strtok(NULL, " ");
-    }
+  unsigned int cursor = 0;
+  mc_heap_ignore_region_t current_region;
 
-    if(i>=6){
-      if(strcmp(lfields[1], ".plt") == 0){
-        size = strtoul(lfields[2], NULL, 16);
-        start_plt_binary = (void *)strtoul(lfields[3], NULL, 16);
-        end_plt_binary = (char *)start_plt_binary + size;
-        plt_found++;
-      }else if(strcmp(lfields[1], ".got.plt") == 0){
-        size = strtoul(lfields[2], NULL, 16);
-        start_got_plt_binary = (char *)strtoul(lfields[3], NULL, 16);
-        end_got_plt_binary = (char *)start_got_plt_binary + size;
-        plt_found++;
-       }
-    }
-    
-    
+  xbt_dynar_foreach(mc_heap_comparison_ignore, cursor, current_region) {
+    mc_heap_ignore_region_t new_region = NULL;
+    new_region = xbt_new0(s_mc_heap_ignore_region_t, 1);
+    new_region->address = current_region->address;
+    new_region->size = current_region->size;
+    new_region->block = current_region->block;
+    new_region->fragment = current_region->fragment;
+    xbt_dynar_push(cpy, &new_region);
   }
 
-  xbt_free(command);
-  xbt_free(line);
-  pclose(fp);
+  return cpy;
 
 }
 
-static void add_value(xbt_dynar_t *list, const char *type, unsigned long int val){
-  variable_value_t value = xbt_new0(s_variable_value_t, 1);
-  value->type = strdup(type);
-  if(strcmp(type, "value") == 0){
-    value->value.res = val;
-  }else{
-    value->value.address = (void *)val;
-  }
-  xbt_dynar_push(*list, &value);
+static void mc_free_snapshot_ignored_data_pvoid(void* data) {
+  mc_snapshot_ignored_data_t ignored_data = (mc_snapshot_ignored_data_t) data;
+  free(ignored_data->data);
 }
 
-static xbt_dynar_t take_snapshot_stacks(mc_snapshot_t *snapshot, void *heap){
-
-  xbt_dynar_t res = xbt_dynar_new(sizeof(s_mc_snapshot_stack_t), snapshot_stack_free_voidp);
+static void MC_snapshot_handle_ignore(mc_snapshot_t snapshot)
+{
+  snapshot->ignored_data = xbt_dynar_new(sizeof(s_mc_snapshot_ignored_data_t), mc_free_snapshot_ignored_data_pvoid);
 
+  // Copy the memory:
   unsigned int cursor = 0;
-  stack_region_t current_stack;
-  
-  xbt_dynar_foreach(stacks_areas, cursor, current_stack){
-    mc_snapshot_stack_t st = xbt_new(s_mc_snapshot_stack_t, 1);
-    st->local_variables = get_local_variables_values(current_stack->context, heap);
-    st->stack_pointer = get_stack_pointer(current_stack->context, heap);
-    xbt_dynar_push(res, &st);
-    (*snapshot)->stack_sizes = xbt_realloc((*snapshot)->stack_sizes, (cursor + 1) * sizeof(size_t));
-    (*snapshot)->stack_sizes[cursor] = current_stack->size - ((char *)st->stack_pointer - (char *)((char *)heap + ((char *)current_stack->address - (char *)std_heap)));
+  mc_checkpoint_ignore_region_t region;
+  xbt_dynar_foreach (mc_checkpoint_ignore, cursor, region) {
+    s_mc_snapshot_ignored_data_t ignored_data;
+    ignored_data.start = region->addr;
+    ignored_data.size = region->size;
+    ignored_data.data = malloc(region->size);
+    memcpy(ignored_data.data, region->addr, region->size);
+    xbt_dynar_push(snapshot->ignored_data, &ignored_data);
   }
 
-  return res;
+  // Zero the memory:
+  xbt_dynar_foreach (mc_checkpoint_ignore, cursor, region) {
+    memset(region->addr, 0, region->size);
+  }
 
 }
 
-static void *get_stack_pointer(void *stack_context, void *heap){
-
-  unw_cursor_t c;
-  int ret;
-  unw_word_t sp;
-
-  ret = unw_init_local(&c, (unw_context_t *)stack_context);
-  if(ret < 0){
-    XBT_INFO("unw_init_local failed");
-    xbt_abort();
+static void MC_snapshot_ignore_restore(mc_snapshot_t snapshot)
+{
+  unsigned int cursor = 0;
+  s_mc_snapshot_ignored_data_t ignored_data;
+  xbt_dynar_foreach (snapshot->ignored_data, cursor, ignored_data) {
+    memcpy(ignored_data.start, ignored_data.data, ignored_data.size);
   }
+}
 
-  unw_get_reg(&c, UNW_REG_SP, &sp);
-
-  return ((char *)heap + (size_t)(((char *)((long)sp) - (char*)std_heap)));
-
+/** @brief Can we remove this snapshot?
+ *
+ * Some snapshots cannot be removed (yet) because we need them
+ * at this point.
+ *
+ * @param snapshot
+ */
+int mc_important_snapshot(mc_snapshot_t snapshot)
+{
+  // We need this snapshot in order to know which
+  // pages needs to be stored in the next snapshot.
+  // This field is only non-NULL when using soft-dirty
+  // page tracking.
+  if (snapshot == mc_model_checker->parent_snapshot)
+    return true;
+
+  return false;
 }
 
-static xbt_strbuff_t get_local_variables_values(void *stack_context, void *heap){
-  
-  unw_cursor_t c;
-  int ret;
+static void MC_get_current_fd(mc_snapshot_t snapshot){
 
-  char frame_name[256];
-  
-  ret = unw_init_local(&c, (unw_context_t *)stack_context);
-  if(ret < 0){
-    XBT_INFO("unw_init_local failed");
-    xbt_abort();
-  }
+  snapshot->total_fd = 0;
 
-  unw_word_t ip, sp, off;
-  dw_frame_t frame;
- 
-  xbt_dynar_t compose = xbt_dynar_new(sizeof(variable_value_t), variable_value_free_voidp);
-
-  xbt_strbuff_t variables = xbt_strbuff_new();
-  xbt_dict_cursor_t dict_cursor;
-  char *variable_name;
-  dw_local_variable_t current_variable;
-  unsigned int cursor = 0, cursor2 = 0;
-  dw_location_entry_t entry = NULL;
-  dw_location_t location_entry = NULL;
-  unw_word_t res;
-  int frame_found = 0;
-  void *frame_pointer_address = NULL;
-  long true_ip;
-  char *to_append;
-
-  while(ret >= 0){
-
-    unw_get_reg(&c, UNW_REG_IP, &ip);
-    unw_get_reg(&c, UNW_REG_SP, &sp);
-
-    unw_get_proc_name(&c, frame_name, sizeof (frame_name), &off);
-
-    frame = xbt_dict_get_or_null(mc_local_variables, frame_name);
-
-    if(frame == NULL){
-      xbt_dynar_free(&compose);
-      xbt_dict_cursor_free(&dict_cursor);
-      return variables;
-    }
+  const size_t fd_dir_path_size = 20;
+  char fd_dir_path[fd_dir_path_size];
+  if (snprintf(fd_dir_path, fd_dir_path_size,
+    "/proc/%lli/fd", (long long int) getpid()) > fd_dir_path_size)
+    xbt_die("Unexpected buffer is too small for fd_dir_path");
 
-    to_append = bprintf("frame_name=%s\n", frame_name);
-    xbt_strbuff_append(variables, to_append);
-    xbt_free(to_append);
-    to_append = bprintf("ip=%lx\n", (unsigned long)ip);
-    xbt_strbuff_append(variables, to_append);
-    xbt_free(to_append);
-    
-    true_ip = (long)frame->low_pc + (long)off;
-
-    /* Get frame pointer */
-    switch(frame->frame_base->type){
-    case e_dw_loclist:
-      while((cursor < xbt_dynar_length(frame->frame_base->location.loclist)) && frame_found == 0){
-        entry = xbt_dynar_get_as(frame->frame_base->location.loclist, cursor, dw_location_entry_t);
-        if((true_ip >= entry->lowpc) && (true_ip < entry->highpc)){
-          frame_found = 1;
-          switch(entry->location->type){
-          case e_dw_compose:
-            xbt_dynar_reset(compose);
-            cursor2 = 0;
-            while(cursor2 < xbt_dynar_length(entry->location->location.compose)){
-              location_entry = xbt_dynar_get_as(entry->location->location.compose, cursor2, dw_location_t);
-              switch(location_entry->type){
-              case e_dw_register:
-                unw_get_reg(&c, location_entry->location.reg, &res);
-                add_value(&compose, "address", (long)res);
-                break;
-              case e_dw_bregister_op:
-                unw_get_reg(&c, location_entry->location.breg_op.reg, &res);
-                add_value(&compose, "address", (long)res + location_entry->location.breg_op.offset);
-                break;
-              default:
-                xbt_dynar_reset(compose);
-                break;
-              }
-              cursor2++;
-            }
-
-            if(!xbt_dynar_is_empty(compose)){
-              frame_pointer_address = xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1, variable_value_t)->value.address ; 
-            }
-            break;
-          default :
-            frame_pointer_address = NULL;
-            break;
-          }
-        }
-        cursor++;
-      }
-      break;
-    default :
-      frame_pointer_address = NULL;
-      break;
-    }
+  DIR* fd_dir = opendir (fd_dir_path);
+  if (fd_dir == NULL)
+    xbt_die("Cannot open directory '/proc/self/fd'\n");
 
-    frame_found = 0;
-    cursor = 0;
-
-    xbt_dict_foreach(frame->variables, dict_cursor, variable_name, current_variable){
-      if(current_variable->location != NULL){
-        switch(current_variable->location->type){
-        case e_dw_compose:
-          xbt_dynar_reset(compose);
-          cursor = 0;
-          while(cursor < xbt_dynar_length(current_variable->location->location.compose)){
-            location_entry = xbt_dynar_get_as(current_variable->location->location.compose, cursor, dw_location_t);
-            switch(location_entry->type){
-            case e_dw_register:
-              unw_get_reg(&c, location_entry->location.reg, &res);
-              add_value(&compose, "value", (long)res);
-              break;
-            case e_dw_bregister_op:
-              unw_get_reg(&c, location_entry->location.breg_op.reg, &res);
-              add_value(&compose, "address", (long)res + location_entry->location.breg_op.offset);
-              break;
-            case e_dw_fbregister_op:
-              if(frame_pointer_address != NULL)
-                add_value(&compose, "address", (long)((char *)frame_pointer_address + location_entry->location.fbreg_op));
-              break;
-            default:
-              xbt_dynar_reset(compose);
-              break;
-            }
-            cursor++;
-          }
-          
-          if(!xbt_dynar_is_empty(compose)){
-            if(strcmp(xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1, variable_value_t)->type, "value") == 0){
-              to_append = bprintf("%s=%lx\n", current_variable->name, xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1, variable_value_t)->value.res);
-              xbt_strbuff_append(variables, to_append);
-              xbt_free(to_append);
-            }else{
-              if((long)xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1,variable_value_t)->value.address < 0 || *((void**)xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1,variable_value_t)->value.address) == NULL){
-                to_append = bprintf("%s=NULL\n", current_variable->name);
-                xbt_strbuff_append(variables, to_append);
-                xbt_free(to_append);
-              }else if(((long)*((void**)xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1,variable_value_t)->value.address) > 0xffffffff) || ((long)*((void**)xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1,variable_value_t)->value.address) < (long)start_text_binary)){
-                to_append = bprintf("%s=%u\n", current_variable->name, (unsigned int)(long)*((void**)xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1, variable_value_t)->value.address));
-                xbt_strbuff_append(variables, to_append);
-                xbt_free(to_append);
-              }else{ 
-                to_append = bprintf("%s=%p\n", current_variable->name, *((void**)xbt_dynar_get_as(compose, xbt_dynar_length(compose) - 1, variable_value_t)->value.address));
-                xbt_strbuff_append(variables, to_append);
-                xbt_free(to_append);
-              }
-            }
-          }else{
-            to_append = bprintf("%s=undefined\n", current_variable->name);
-            xbt_strbuff_append(variables, to_append);
-            xbt_free(to_append);
-          }
-          break;
-        default :
-          break;
-        }
-      }else{
-        to_append = bprintf("%s=undefined\n", current_variable->name);
-        xbt_strbuff_append(variables, to_append);
-        xbt_free(to_append);
-      }
-    }    
- 
-    ret = unw_step(&c);
-     
-  }
+  size_t total_fd = 0;
+  struct dirent* fd_number;
+  while ((fd_number = readdir(fd_dir))) {
 
-  xbt_dynar_free(&compose);
-  xbt_dict_cursor_free(&dict_cursor);
+    int fd_value = atoi(fd_number->d_name);
 
-  return variables;
+    if(fd_value < 3)
+      continue;
 
-}
+    const size_t source_size = 25;
+    char source[25];
+    if (snprintf(source, source_size, "/proc/self/fd/%s", fd_number->d_name) > source_size)
+      xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
 
-static void print_local_variables_values(xbt_dynar_t all_variables){
+    const size_t link_size = 200;
+    char link[200];
+    size_t res = readlink(source, link, link_size);
+    if (res<0) {
+      xbt_die("Could not read link for %s", source);
+    }
+    if (res==200) {
+      xbt_die("Buffer to small for link of %s", source);
+    }
+    link[res] = '\0';
 
-  unsigned cursor = 0;
-  mc_snapshot_stack_t stack;
+    if(smpi_is_privatisation_file(link))
+      continue;
 
-  xbt_dynar_foreach(all_variables, cursor, stack){
-    XBT_INFO("%s", stack->local_variables->data);
-  }
-}
+    // This is (probably) the DIR* we are reading:
+    // TODO, read all the file entries at once and close the DIR.*
+    if(strcmp(fd_dir_path, link) == 0)
+      continue;
 
+    // We don't handle them.
+    // It does not mean we should silently ignore them however.
+    if (strncmp(link, "pipe:", 5) == 0 || strncmp(link, "socket:", 7) == 0)
+      continue;
 
-static void snapshot_stack_free(mc_snapshot_stack_t s){
-  if(s){
-    xbt_free(s->local_variables->data);
-    xbt_free(s->local_variables);
-    xbt_free(s);
+    // This is probably a shared memory used by lttng-ust:
+    if(strncmp("/dev/shm/ust-shm-tmp-", link, 21)==0)
+      continue;
+
+    // Add an entry for this FD in the snapshot:
+    fd_infos_t fd = xbt_new0(s_fd_infos_t, 1);
+    fd->filename = strdup(link);
+    fd->number = fd_value;
+    fd->flags = fcntl(fd_value, F_GETFL) | fcntl(fd_value, F_GETFD) ;
+    fd->current_position = lseek(fd_value, 0, SEEK_CUR);
+    snapshot->current_fd = xbt_realloc(snapshot->current_fd, (total_fd + 1) * sizeof(fd_infos_t));
+    snapshot->current_fd[total_fd] = fd;
+    total_fd++;
   }
-}
 
-void snapshot_stack_free_voidp(void *s){
-  snapshot_stack_free((mc_snapshot_stack_t) * (void **) s);
+  snapshot->total_fd = total_fd;
+  closedir (fd_dir);
 }
 
-mc_snapshot_t SIMIX_pre_mc_snapshot(smx_simcall_t simcall){
-  return MC_take_snapshot();
-}
+mc_snapshot_t MC_take_snapshot(int num_state)
+{
+
+  mc_snapshot_t snapshot = xbt_new0(s_mc_snapshot_t, 1);
+  snapshot->enabled_processes = xbt_dynar_new(sizeof(int), NULL);
+  smx_process_t process;
+  xbt_swag_foreach(process, simix_global->process_list) {
+    xbt_dynar_push_as(snapshot->enabled_processes, int, (int)process->pid);
+  }
 
-void *MC_snapshot(void){
+  MC_snapshot_handle_ignore(snapshot);
 
-  return simcall_mc_snapshot();
-  
-}
+  MC_get_current_fd(snapshot);
 
-void variable_value_free(variable_value_t v){
-  if(v){
-    xbt_free(v->type);
-    xbt_free(v);
+  /* Save the std heap and the writable mapped pages of libsimgrid and binary */
+  MC_get_memory_regions(snapshot);
+  if (_sg_mc_sparse_checkpoint && _sg_mc_soft_dirty) {
+    mc_softdirty_reset();
   }
-}
 
-void variable_value_free_voidp(void* v){
-  variable_value_free((variable_value_t) * (void **)v);
-}
+  snapshot->to_ignore = MC_take_snapshot_ignore();
 
-static void get_hash_global(char *snapshot_hash, void *data1, void *data2){
-  
-  unsigned int cursor = 0;
-  size_t offset; 
-  global_variable_t current_var; 
-  void *addr_pointed = NULL;
-  void *res = NULL;
-
-  xbt_strbuff_t clear = xbt_strbuff_new();
-  
-  xbt_dynar_foreach(mc_global_variables, cursor, current_var){
-    if(current_var->address < start_data_libsimgrid){ /* binary */
-      offset = (char *)current_var->address - (char *)start_data_binary;
-      addr_pointed = *((void **)((char *)data2 + offset));
-      if(((addr_pointed >= start_plt_binary && addr_pointed <= end_plt_binary)) || ((addr_pointed >= std_heap && (char *)addr_pointed <= (char *)std_heap + STD_HEAP_SIZE )))
-        continue;
-      res = xbt_malloc0(current_var->size + 1);
-      memset(res, 0, current_var->size + 1);
-      memcpy(res, (char*)data2 + offset, current_var->size);
-    }else{ /* libsimgrid */
-      offset = (char *)current_var->address - (char *)start_data_libsimgrid;
-      addr_pointed = *((void **)((char *)data1 + offset));
-      if((addr_pointed >= start_plt_libsimgrid && addr_pointed <= end_plt_libsimgrid) || (addr_pointed >= std_heap && (char *)addr_pointed <= (char *)std_heap + STD_HEAP_SIZE ))
-        continue;
-      res = xbt_malloc0(current_var->size + 1);
-      memset(res, 0, current_var->size + 1);
-      memcpy(res, (char*)data1 + offset, current_var->size);
-    }
-    if(res != NULL){
-      xbt_strbuff_append(clear, (const char*)res);
-      xbt_free(res);
-      res = NULL;
+  if (_sg_mc_visited > 0 || strcmp(_sg_mc_property_file, "")) {
+    snapshot->stacks =
+        MC_take_snapshot_stacks(&snapshot);
+    if (_sg_mc_hash && snapshot->stacks != NULL) {
+      snapshot->hash = mc_hash_processes_state(num_state, snapshot->stacks);
+    } else {
+      snapshot->hash = 0;
     }
+  } else {
+    snapshot->hash = 0;
   }
 
-  xbt_sha(clear->data, snapshot_hash);
+  MC_snapshot_ignore_restore(snapshot);
+  if (_sg_mc_sparse_checkpoint && _sg_mc_soft_dirty) {
+    mc_model_checker->parent_snapshot = snapshot;
+  }
+  return snapshot;
+}
 
-  xbt_strbuff_free(clear);
+void MC_restore_snapshot(mc_snapshot_t snapshot)
+{
+  mc_snapshot_t parent_snapshot = mc_model_checker->parent_snapshot;
 
-}
+  int new_fd;
+  unsigned int i;
+  for (i = 0; i < NB_REGIONS; i++) {
+    // For privatized, variables we decided it was not necessary to take the snapshot:
+    if (snapshot->regions[i])
+      MC_region_restore(snapshot->regions[i],
+        parent_snapshot ? parent_snapshot->regions[i] : NULL);
+  }
 
-static void get_hash_local(char *snapshot_hash, xbt_dynar_t stacks){
-
-  xbt_dynar_t tokens = NULL, s_tokens = NULL;
-  unsigned int cursor1 = 0, cursor2 = 0;
-  mc_snapshot_stack_t current_stack;
-  char *frame_name = NULL;
-  void *addr;
-
-  xbt_strbuff_t clear = xbt_strbuff_new();
-
-  while(cursor1 < xbt_dynar_length(stacks)){
-    current_stack = xbt_dynar_get_as(stacks, cursor1, mc_snapshot_stack_t);
-    tokens = xbt_str_split(current_stack->local_variables->data, NULL);
-    cursor2 = 0;
-    while(cursor2 < xbt_dynar_length(tokens)){
-      s_tokens = xbt_str_split(xbt_dynar_get_as(tokens, cursor2, char *), "=");
-      if(xbt_dynar_length(s_tokens) > 1){
-        if(strcmp(xbt_dynar_get_as(s_tokens, 0, char *), "frame_name") == 0){
-          xbt_free(frame_name);
-          frame_name = xbt_strdup(xbt_dynar_get_as(s_tokens, 1, char *));
-          xbt_strbuff_append(clear, (const char*)xbt_dynar_get_as(tokens, cursor2, char *));
-          cursor2++;
-          xbt_dynar_free(&s_tokens);
-          continue;
-        }
-        addr = (void *) strtoul(xbt_dynar_get_as(s_tokens, 1, char *), NULL, 16);
-        if(addr > std_heap && (char *)addr <= (char *)std_heap + STD_HEAP_SIZE){
-          cursor2++;
-          xbt_dynar_free(&s_tokens);
-          continue;
-        }
-        if(is_stack_ignore_variable(frame_name, xbt_dynar_get_as(s_tokens, 0, char *))){
-          cursor2++;
-          xbt_dynar_free(&s_tokens);
-          continue;
-        }
-        xbt_strbuff_append(clear, (const char *)xbt_dynar_get_as(tokens, cursor2, char *));
+#ifdef HAVE_SMPI
+  if (snapshot->privatization_regions) {
+    // Restore the global variables of the application separately for each
+    // simulated process:
+    for (i = 0; i < smpi_process_count(); i++) {
+      if (snapshot->privatization_regions[i]) {
+        MC_region_restore(snapshot->privatization_regions[i],
+          parent_snapshot ? parent_snapshot->privatization_regions[i] : NULL);
       }
-      xbt_dynar_free(&s_tokens);
-      cursor2++;
     }
-    xbt_dynar_free(&tokens);
-    cursor1++;
   }
+  if(snapshot->privatization_index >= 0) {
+    // We just rewrote the global variables.
+    // The privatisation segment SMPI thinks
+    // is mapped might be inconsistent with the segment which
+    // is really mapped in memory (kernel state).
+    // We ask politely SMPI to map the segment anyway,
+    // even if it thinks it is the current one:
+    smpi_really_switch_data_segment(snapshot->privatization_index);
+  }
+#endif
 
-  xbt_free(frame_name);
+  for(i=0; i < snapshot->total_fd; i++){
+    
+    new_fd = open(snapshot->current_fd[i]->filename, snapshot->current_fd[i]->flags);
+    if (new_fd <0) {
+      xbt_die("Could not reopen the file %s fo restoring the file descriptor",
+        snapshot->current_fd[i]->filename);
+    }
+    if(new_fd != -1 && new_fd != snapshot->current_fd[i]->number){
+      dup2(new_fd, snapshot->current_fd[i]->number);
+      //fprintf(stderr, "%p\n", fdopen(snapshot->current_fd[i]->number, "rw"));
+      close(new_fd);
+    };
+    lseek(snapshot->current_fd[i]->number, snapshot->current_fd[i]->current_position, SEEK_SET);
+  }
 
-  xbt_sha(clear->data, snapshot_hash);
+  if (_sg_mc_sparse_checkpoint && _sg_mc_soft_dirty) {
+    mc_softdirty_reset();
+  }
 
-  xbt_strbuff_free(clear);
+  MC_snapshot_ignore_restore(snapshot);
+  if (_sg_mc_sparse_checkpoint && _sg_mc_soft_dirty) {
+    mc_model_checker->parent_snapshot = snapshot;
+  }
 
 }
 
+mc_snapshot_t simcall_HANDLER_mc_snapshot(smx_simcall_t simcall)
+{
+  return MC_take_snapshot(1);
+}
 
-static xbt_dynar_t take_snapshot_ignore(){
-  
-  if(mc_heap_comparison_ignore == NULL)
-    return NULL;
-
-  xbt_dynar_t cpy = xbt_dynar_new(sizeof(mc_heap_ignore_region_t), heap_ignore_region_free_voidp);
-
-  unsigned int cursor = 0;
-  mc_heap_ignore_region_t current_region;
-
-  xbt_dynar_foreach(mc_heap_comparison_ignore, cursor, current_region){
-    mc_heap_ignore_region_t new_region = NULL;
-    new_region = xbt_new0(s_mc_heap_ignore_region_t, 1);
-    new_region->address = current_region->address;
-    new_region->size = current_region->size;
-    new_region->block = current_region->block;
-    new_region->fragment = current_region->fragment;
-    xbt_dynar_push(cpy, &new_region);
-  }
-
-  return cpy;
-
+void *MC_snapshot(void)
+{
+  return simcall_mc_snapshot();
 }