/* 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 <algorithm>
#include <cerrno>
#include <climits>
#include <cstdint>
SmpiPrivStrategies smpi_privatize_global_variables;
static void* smpi_data_exe_copy;
+// Initialized by smpi_prepare_global_memory_segment().
+static std::vector<simgrid::xbt::VmMap> initial_vm_map;
+
// We keep a copy of all the privatization regions: We can then delete everything easily by iterating over this
// collection and nothing can be leaked. We could also iterate over all actors but we would have to be diligent when two
// actors use the same privatization region (so, smart pointers would have to be used etc.)
// Use a std::deque so that pointers remain valid after push_back().
static std::deque<s_smpi_privatization_region_t> smpi_privatization_regions;
-static const int PROT_RWX = (PROT_READ | PROT_WRITE | PROT_EXEC);
-static const int PROT_RW = (PROT_READ | PROT_WRITE );
-XBT_ATTRIB_UNUSED static const int PROT_RX = (PROT_READ | PROT_EXEC );
+static constexpr int PROT_RWX = PROT_READ | PROT_WRITE | PROT_EXEC;
+static constexpr int PROT_RW = PROT_READ | PROT_WRITE;
+
+/** Take a snapshot of the process' memory map.
+ */
+void smpi_prepare_global_memory_segment()
+{
+ initial_vm_map = simgrid::xbt::get_memory_map(getpid());
+}
static void smpi_get_executable_global_size()
{
if (i->pathname == full_name && (i->prot & PROT_RWX) == PROT_RW) {
smpi_data_exe_start = (char*)i->start_addr;
smpi_data_exe_size = i->end_addr - i->start_addr;
- ++i;
/* Here we are making the assumption that a suitable empty region
following the rw- area is the end of the data segment. It would
be better to check with the size of the data segment. */
+ ++i;
if (i != map.end() && i->pathname.empty() && (i->prot & PROT_RWX) == PROT_RW &&
(char*)i->start_addr == smpi_data_exe_start + smpi_data_exe_size) {
- smpi_data_exe_size = (char*)i->end_addr - smpi_data_exe_start;
+ // Only count this region if it was not already present in the initial map.
+ auto found = std::find_if(begin(initial_vm_map), end(initial_vm_map),
+ [&i](const simgrid::xbt::VmMap& m) { return m.start_addr == i->start_addr; });
+ if (found == end(initial_vm_map))
+ smpi_data_exe_size = (char*)i->end_addr - smpi_data_exe_start;
}
return;
}
XBT_DEBUG("Switching data frame to the one of process %ld", actor->get_pid());
simgrid::smpi::Process* process = smpi_process_remote(actor);
int current = process->privatized_region()->file_descriptor;
- void* tmp =
- mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, current, 0);
+ void* tmp = mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_RW, MAP_FIXED | MAP_SHARED, current, 0);
if (tmp != TOPAGE(smpi_data_exe_start))
xbt_die("Couldn't map the new region (errno %d): %s", errno, strerror(errno));
smpi_loaded_page = actor->get_pid();
*/
void smpi_backup_global_memory_segment()
{
- xbt_assert(HAVE_PRIVATIZATION, "You are trying to use privatization on a system that does not support it. Don't.");
+#if HAVE_PRIVATIZATION
smpi_get_executable_global_size();
+ initial_vm_map.clear();
+ initial_vm_map.shrink_to_fit();
XBT_DEBUG("bss+data segment found : size %d starting at %p", smpi_data_exe_size, smpi_data_exe_start);
// Make a copy of the data segment. This clean copy is retained over the whole runtime
// of the simulation and can be used to initialize a dynamically added, new process.
asan_safe_memcpy(smpi_data_exe_copy, TOPAGE(smpi_data_exe_start), smpi_data_exe_size);
+#else /* ! HAVE_PRIVATIZATION */
+ xbt_die("You are trying to use privatization on a system that does not support it. Don't.");
+#endif
}
// Initializes the memory mapping for a single process and returns the privatization region
xbt_die("Impossible to set the size of the temporary file for memory mapping");
/* Ask for a free region */
- address = mmap(nullptr, smpi_data_exe_size, PROT_READ | PROT_WRITE, MAP_SHARED, file_descriptor, 0);
+ address = mmap(nullptr, smpi_data_exe_size, PROT_RW, MAP_SHARED, file_descriptor, 0);
if (address == MAP_FAILED)
xbt_die("Couldn't find a free region for memory mapping");