+ exit(1);
+}
+
+#ifndef _WIN32
+static void segvhandler(int signum, siginfo_t* siginfo, void* /*context*/)
+{
+ if ((siginfo->si_signo == SIGSEGV && siginfo->si_code == SEGV_ACCERR) || siginfo->si_signo == SIGBUS) {
+ fprintf(stderr,
+ "Access violation or Bus error detected.\n"
+ "This probably comes from a programming error in your code, or from a stack\n"
+ "overflow. If you are certain of your code, try increasing the stack size\n"
+ " --cfg=contexts/stack-size:XXX (current size is %u KiB).\n"
+ "\n"
+ "If it does not help, this may have one of the following causes:\n"
+ "a bug in SimGrid, a bug in the OS or a bug in a third-party libraries.\n"
+ "Failing hardware can sometimes generate such errors too.\n"
+ "\n"
+ "If you think you've found a bug in SimGrid, please report it along with a\n"
+ "Minimal Working Example (MWE) reproducing your problem and a full backtrace\n"
+ "of the fault captured with gdb or valgrind.\n",
+ smx_context_stack_size / 1024);
+ } else if (siginfo->si_signo == SIGSEGV) {
+ fprintf(stderr, "Segmentation fault.\n");
+#if HAVE_SMPI
+ if (smpi_enabled() && smpi_cfg_privatization() == SmpiPrivStrategies::NONE) {
+#if HAVE_PRIVATIZATION
+ fprintf(stderr, "Try to enable SMPI variable privatization with --cfg=smpi/privatization:yes.\n");
+#else
+ fprintf(stderr, "Sadly, your system does not support --cfg=smpi/privatization:yes (yet).\n");
+#endif /* HAVE_PRIVATIZATION */
+ }
+#endif /* HAVE_SMPI */
+ }
+ std::raise(signum);
+}
+
+/**
+ * Install signal handler for SIGSEGV. Check that nobody has already installed
+ * its own handler. For example, the Java VM does this.
+ */
+static void install_segvhandler()
+{
+ stack_t old_stack;
+
+ if (simgrid::kernel::context::Context::install_sigsegv_stack(&old_stack, true) == -1) {
+ XBT_WARN("Failed to register alternate signal stack: %s", strerror(errno));
+ return;
+ }
+ if (not(old_stack.ss_flags & SS_DISABLE)) {
+ XBT_DEBUG("An alternate stack was already installed (sp=%p, size=%zu, flags=%x). Restore it.", old_stack.ss_sp,
+ old_stack.ss_size, (unsigned)old_stack.ss_flags);
+ sigaltstack(&old_stack, nullptr);
+ }
+
+ struct sigaction action;
+ struct sigaction old_action;
+ action.sa_sigaction = &segvhandler;
+ action.sa_flags = SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
+ sigemptyset(&action.sa_mask);
+
+ /* Linux tend to raise only SIGSEGV where other systems also raise SIGBUS on severe error */
+ for (int sig : {SIGSEGV, SIGBUS}) {
+ if (sigaction(sig, &action, &old_action) == -1) {
+ XBT_WARN("Failed to register signal handler for signal %d: %s", sig, strerror(errno));
+ continue;
+ }
+ if ((old_action.sa_flags & SA_SIGINFO) || old_action.sa_handler != SIG_DFL) {
+ XBT_DEBUG("A signal handler was already installed for signal %d (%p). Restore it.", sig,
+ (old_action.sa_flags & SA_SIGINFO) ? (void*)old_action.sa_sigaction : (void*)old_action.sa_handler);
+ sigaction(sig, &old_action, nullptr);
+ }
+ }
+}
+
+#endif /* _WIN32 */