[mc] Better detection of the segments

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

diff --git a/src/mc/mc_checkpoint.cpp b/src/mc/mc_checkpoint.cpp
index f4f6cd8..eaf4e48 100644 (file)
--- a/src/mc/mc_checkpoint.cpp
+++ b/src/mc/mc_checkpoint.cpp
@@ -115,7 +115,7 @@ RegionSnapshot privatized_region(
 #endif
 
 static
-void add_region(int index, mc_snapshot_t snapshot,
+void add_region(int index, simgrid::mc::Snapshot* snapshot,
                                   simgrid::mc::RegionType type,
                                   simgrid::mc::ObjectInformation* object_info,
                                   void *start_addr, void* permanent_addr,
@@ -148,7 +148,7 @@ void add_region(int index, mc_snapshot_t snapshot,
   return;
 }
 
-static void get_memory_regions(simgrid::mc::Process* process, mc_snapshot_t snapshot)
+static void get_memory_regions(simgrid::mc::Process* process, simgrid::mc::Snapshot* snapshot)
 {
   const size_t n = process->object_infos.size();
   snapshot->snapshot_regions.resize(n + 1);
@@ -181,10 +181,13 @@ static void get_memory_regions(simgrid::mc::Process* process, mc_snapshot_t snap
     snapshot->privatization_index = simgrid::mc::ProcessIndexMissing;
 }
 
+#define PROT_RWX (PROT_READ | PROT_WRITE | PROT_EXEC)
+#define PROT_RW (PROT_READ | PROT_WRITE)
+#define PROT_RX (PROT_READ | PROT_EXEC)
+
 /** \brief Fills the position of the segments (executable, read-only, read/write).
- *
- *  `dl_iterate_phdr` would be more robust but would not work in cross-process.
  * */
+// TODO, use the ELF segment information for more robustness
 void find_object_address(
   std::vector<simgrid::xbt::VmMap> const& maps,
   simgrid::mc::ObjectInformation* result)
@@ -201,24 +204,43 @@ void find_object_address(
       continue;
     }
     free(map_basename);
-    if ((reg.prot & PROT_WRITE)) {
+
+    // This is the non-GNU_RELRO-part of the data segment:
+    if (reg.prot == PROT_RW) {
       xbt_assert(!result->start_rw,
                  "Multiple read-write segments for %s, not supported",
                  maps[i].pathname.c_str());
       result->start_rw = (char*) reg.start_addr;
       result->end_rw = (char*) reg.end_addr;
-      // .bss is usually after the .data:
-      simgrid::xbt::VmMap const& next = maps[i + 1];
-      if (next.pathname.empty() && (next.prot & PROT_WRITE)
-          && next.start_addr == reg.end_addr)
+
+      // The next VMA might be end of the data segment:
+      if (i + 1 < maps.size()
+          && maps[i + 1].pathname.empty()
+          && maps[i + 1].prot == PROT_RW
+          && maps[i + 1].start_addr == reg.end_addr)
         result->end_rw = (char*) maps[i + 1].end_addr;
-    } else if ((reg.prot & PROT_READ) && (reg.prot & PROT_EXEC)) {
+    }
+
+    // This is the text segment:
+    else if (reg.prot == PROT_RX) {
       xbt_assert(!result->start_exec,
                  "Multiple executable segments for %s, not supported",
                  maps[i].pathname.c_str());
       result->start_exec = (char*) reg.start_addr;
       result->end_exec = (char*) reg.end_addr;
-    } else if ((reg.prot & PROT_READ) && !(reg.prot & PROT_EXEC)) {
+
+      // The next VMA might be end of the data segment:
+      if (i + 1 < maps.size()
+          && maps[i + 1].pathname.empty()
+          && maps[i + 1].prot == PROT_RW
+          && maps[i + 1].start_addr == reg.end_addr) {
+        result->start_rw = (char*) maps[i + 1].start_addr;
+        result->end_rw = (char*) maps[i + 1].end_addr;
+      }
+    }
+
+    // This is the GNU_RELRO-part of the data segment:
+    else if (reg.prot == PROT_READ) {
       xbt_assert(!result->start_ro,
                  "Multiple read only segments for %s, not supported",
                  maps[i].pathname.c_str());
@@ -394,7 +416,7 @@ static std::vector<s_mc_stack_frame_t> unwind_stack_frames(simgrid::mc::UnwindCo
   return std::move(result);
 };
 
-static std::vector<s_mc_snapshot_stack_t> take_snapshot_stacks(mc_snapshot_t * snapshot)
+static std::vector<s_mc_snapshot_stack_t> take_snapshot_stacks(simgrid::mc::Snapshot* * snapshot)
 {
   std::vector<s_mc_snapshot_stack_t> res;
 
@@ -425,7 +447,7 @@ static std::vector<s_mc_snapshot_stack_t> take_snapshot_stacks(mc_snapshot_t * s
 
 }
 
-static void snapshot_handle_ignore(mc_snapshot_t snapshot)
+static void snapshot_handle_ignore(simgrid::mc::Snapshot* snapshot)
 {
   xbt_assert(snapshot->process());
   
@@ -447,7 +469,7 @@ static void snapshot_handle_ignore(mc_snapshot_t snapshot)
 
 }
 
-static void snapshot_ignore_restore(mc_snapshot_t snapshot)
+static void snapshot_ignore_restore(simgrid::mc::Snapshot* snapshot)
 {
   for (auto const& ignored_data : snapshot->ignored_data)
     snapshot->process()->write_bytes(
@@ -540,13 +562,13 @@ static std::vector<s_fd_infos_t> get_current_fds(pid_t pid)
   return std::move(fds);
 }
 
-mc_snapshot_t take_snapshot(int num_state)
+simgrid::mc::Snapshot* take_snapshot(int num_state)
 {
   XBT_DEBUG("Taking snapshot %i", num_state);
 
   simgrid::mc::Process* mc_process = &mc_model_checker->process();
 
-  mc_snapshot_t snapshot = new simgrid::mc::Snapshot(mc_process);
+  simgrid::mc::Snapshot* snapshot = new simgrid::mc::Snapshot(mc_process);
 
   snapshot->num_state = num_state;
 
@@ -584,7 +606,7 @@ mc_snapshot_t take_snapshot(int num_state)
 }
 
 static inline
-void restore_snapshot_regions(mc_snapshot_t snapshot)
+void restore_snapshot_regions(simgrid::mc::Snapshot* snapshot)
 {
   for(std::unique_ptr<s_mc_mem_region_t> const& region : snapshot->snapshot_regions) {
     // For privatized, variables we decided it was not necessary to take the snapshot:
@@ -605,7 +627,7 @@ void restore_snapshot_regions(mc_snapshot_t snapshot)
 }
 
 static inline
-void restore_snapshot_fds(mc_snapshot_t snapshot)
+void restore_snapshot_fds(simgrid::mc::Snapshot* snapshot)
 {
   if (mc_mode == MC_MODE_SERVER)
     xbt_die("FD snapshot not implemented in client/server mode.");
@@ -624,7 +646,7 @@ void restore_snapshot_fds(mc_snapshot_t snapshot)
   }
 }
 
-void restore_snapshot(mc_snapshot_t snapshot)
+void restore_snapshot(simgrid::mc::Snapshot* snapshot)
 {
   XBT_DEBUG("Restore snapshot %i", snapshot->num_state);
   const bool use_soft_dirty = _sg_mc_sparse_checkpoint && _sg_mc_soft_dirty;