[mc] Protect snapshots against write

[simgrid.git] / src / mc / mc_checkpoint.c

diff --git a/src/mc/mc_checkpoint.c b/src/mc/mc_checkpoint.c
index 44c502d..7864e2c 100644 (file)
--- a/src/mc/mc_checkpoint.c
+++ b/src/mc/mc_checkpoint.c
@@ -54,7 +54,7 @@ static void local_variable_free_voidp(void *v){
 
 static void MC_region_destroy(mc_mem_region_t reg)
 {
-  xbt_free(reg->data);
+  munmap(reg->data, reg->size);
   xbt_free(reg);
 }
 
@@ -67,8 +67,8 @@ void MC_free_snapshot(mc_snapshot_t snapshot){
   xbt_dynar_free(&(snapshot->stacks));
   xbt_dynar_free(&(snapshot->to_ignore));
 
-  size_t n = snapshot->nb_processes;
-  if(snapshot->privatization_regions) {
+  if(snapshot->privatization_regions){
+    size_t n = snapshot->nb_processes;
     for(i=0; i!=n; ++i) {
       MC_region_destroy(snapshot->privatization_regions[i]);
     }
@@ -87,8 +87,10 @@ static mc_mem_region_t MC_region_new(int type, void *start_addr, size_t size)
   mc_mem_region_t new_reg = xbt_new(s_mc_mem_region_t, 1);
   new_reg->start_addr = start_addr;
   new_reg->size = size;
-  new_reg->data = xbt_malloc(size);
+  new_reg->data = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
   memcpy(new_reg->data, start_addr, size);
+  mprotect(new_reg->data, size, PROT_READ);
+  madvise(new_reg->data, size, MADV_MERGEABLE);
 
   XBT_DEBUG("New region : type : %d, data : %p (real addr %p), size : %zu", type, new_reg->data, start_addr, size);