#include "history.h"
#include "bugmessage.h"
#include "params.h"
+#include "plugins.h"
ModelChecker *model = NULL;
-/** Wrapper to run the user's main function, with appropriate arguments */
-void user_main_wrapper(void *)
+void placeholder(void *) {
+ ASSERT(0);
+}
+
+#include <signal.h>
+
+#define SIGSTACKSIZE 65536
+static void mprot_handle_pf(int sig, siginfo_t *si, void *unused)
{
-#ifdef TLS
- model->get_execution()->getTLSSize();
-#endif
- user_main(model->params.argc, model->params.argv);
+ model_print("Segmentation fault at %p\n", si->si_addr);
+ model_print("For debugging, place breakpoint at: %s:%d\n",
+ __FILE__, __LINE__);
+ print_trace(); // Trace printing may cause dynamic memory allocation
+ while(1)
+ ;
+}
+
+void install_handler() {
+ stack_t ss;
+ ss.ss_sp = model_malloc(SIGSTACKSIZE);
+ ss.ss_size = SIGSTACKSIZE;
+ ss.ss_flags = 0;
+ sigaltstack(&ss, NULL);
+ struct sigaction sa;
+ sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART | SA_ONSTACK;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_sigaction = mprot_handle_pf;
+
+ if (sigaction(SIGSEGV, &sa, NULL) == -1) {
+ perror("sigaction(SIGSEGV)");
+ exit(EXIT_FAILURE);
+ }
+
}
/** @brief Constructor */
ModelChecker::ModelChecker() :
/* Initialize default scheduler */
params(),
- restart_flag(false),
scheduler(new Scheduler()),
- execution(new ModelExecution(this, scheduler)),
history(new ModelHistory()),
+ execution(new ModelExecution(this, scheduler)),
execution_number(1),
trace_analyses(),
inspect_plugin(NULL)
{
+ model_print("C11Tester\n"
+ "Copyright (c) 2013 and 2019 Regents of the University of California. All rights reserved.\n"
+ "Distributed under the GPLv2\n"
+ "Written by Weiyu Luo, Brian Norris, and Brian Demsky\n\n");
memset(&stats,0,sizeof(struct execution_stats));
- init_thread = new Thread(execution->get_next_id(), (thrd_t *) model_malloc(sizeof(thrd_t)), &user_main_wrapper, NULL, NULL); // L: user_main_wrapper passes the user program
+ init_thread = new Thread(execution->get_next_id(), (thrd_t *) model_malloc(sizeof(thrd_t)), &placeholder, NULL, NULL);
#ifdef TLS
init_thread->setTLS((char *)get_tls_addr());
#endif
execution->add_thread(init_thread);
scheduler->set_current_thread(init_thread);
+ register_plugins();
execution->setParams(¶ms);
param_defaults(¶ms);
+ parse_options(¶ms);
initRaceDetector();
+ /* Configure output redirection for the model-checker */
+ install_handler();
}
/** @brief Destructor */
for (unsigned int i = 0;i < get_num_threads();i++)
delete get_thread(int_to_id(i))->get_pending();
- snapshot_backtrack_before(0);
+ snapshot_roll_back(snapshot);
}
/** @return the number of user threads created during this execution */
* @param msg Descriptive message for the bug (do not include newline char)
* @return True if bug is immediately-feasible
*/
-bool ModelChecker::assert_bug(const char *msg, ...)
+void ModelChecker::assert_bug(const char *msg, ...)
{
char str[800];
vsnprintf(str, sizeof(str), msg, ap);
va_end(ap);
- return execution->assert_bug(str);
+ execution->assert_bug(str);
}
/**
void ModelChecker::assert_user_bug(const char *msg)
{
/* If feasible bug, bail out now */
- if (assert_bug(msg))
- switch_to_master(NULL);
+ assert_bug(msg);
+ switch_thread(NULL);
}
/** @brief Print bug report listing for this execution (if any bugs exist) */
void ModelChecker::record_stats()
{
stats.num_total ++;
- if (!execution->isfeasibleprefix())
- stats.num_infeasible ++;
- else if (execution->have_bug_reports())
+ if (execution->have_bug_reports())
stats.num_buggy_executions ++;
else if (execution->is_complete_execution())
stats.num_complete ++;
else {
- stats.num_redundant ++;
-
+ //All threads are sleeping
/**
* @todo We can violate this ASSERT() when fairness/sleep sets
* conflict to cause an execution to terminate, e.g. with:
void ModelChecker::print_stats() const
{
model_print("Number of complete, bug-free executions: %d\n", stats.num_complete);
- model_print("Number of redundant executions: %d\n", stats.num_redundant);
model_print("Number of buggy executions: %d\n", stats.num_buggy_executions);
- model_print("Number of infeasible executions: %d\n", stats.num_infeasible);
model_print("Total executions: %d\n", stats.num_total);
}
* @return If there are more executions to explore, return true. Otherwise,
* return false.
*/
-bool ModelChecker::next_execution()
+void ModelChecker::finish_execution(bool more_executions)
{
DBG();
/* Is this execution a feasible execution that's worth bug-checking? */
- bool complete = execution->isfeasibleprefix() &&
- (execution->is_complete_execution() ||
+ bool complete = (execution->is_complete_execution() ||
execution->have_bug_reports());
/* End-of-execution bug checks */
else
clear_program_output();
- if (restart_flag) {
- do_restart();
- return true;
- }
-// test code
execution_number ++;
- reset_to_initial_state();
- return false;
+ history->set_new_exec_flag();
+
+ if (more_executions)
+ reset_to_initial_state();
}
/** @brief Run trace analyses on complete trace */
return execution->get_thread(act);
}
-/**
- * Switch from a model-checker context to a user-thread context. This is the
- * complement of ModelChecker::switch_to_master and must be called from the
- * model-checker context
- *
- * @param thread The user-thread to switch to
- */
-void ModelChecker::switch_from_master(Thread *thread)
+void ModelChecker::startRunExecution(Thread *old) {
+ while (true) {
+ if (params.traceminsize != 0 &&
+ execution->get_curr_seq_num() > checkfree) {
+ checkfree += params.checkthreshold;
+ execution->collectActions();
+ }
+
+ thread_chosen = false;
+ curr_thread_num = 1;
+
+ Thread *thr = getNextThread();
+ if (thr != nullptr) {
+ scheduler->set_current_thread(thr);
+
+ if (Thread::swap(old, thr) < 0) {
+ perror("swap threads");
+ exit(EXIT_FAILURE);
+ }
+ return;
+ }
+
+ if (execution->has_asserted()) {
+ finishRunExecution(old);
+ return;
+ }
+ if (!chosen_thread)
+ chosen_thread = get_next_thread();
+ if (!chosen_thread || chosen_thread->is_model_thread()) {
+ finishRunExecution(old);
+ return;
+ }
+ if (chosen_thread->just_woken_up()) {
+ chosen_thread->set_wakeup_state(false);
+ chosen_thread->set_pending(NULL);
+ chosen_thread = NULL;
+ // Allow this thread to stash the next pending action
+ continue;
+ }
+
+ /* Consume the next action for a Thread */
+ consumeAction();
+
+ if (should_terminate_execution()) {
+ finishRunExecution(old);
+ return;
+ }
+ }
+}
+
+Thread* ModelChecker::getNextThread()
{
- scheduler->set_current_thread(thread);
- Thread::swap(&system_context, thread);
+ Thread *nextThread = nullptr;
+ for (unsigned int i = curr_thread_num;i < get_num_threads();i++) {
+ thread_id_t tid = int_to_id(i);
+ Thread *thr = get_thread(tid);
+
+ if (!thr->is_complete() && !thr->get_pending()) {
+ curr_thread_num = i;
+ nextThread = thr;
+ break;
+ }
+
+ /* Don't schedule threads which should be disabled */
+ ModelAction *act = thr->get_pending();
+ if (act && execution->is_enabled(thr) && !execution->check_action_enabled(act)) {
+ scheduler->sleep(thr);
+ }
+ chooseThread(act, thr);
+ }
+ return nextThread;
}
-/**
- * Switch from a user-context to the "master thread" context (a.k.a. system
- * context). This switch is made with the intention of exploring a particular
- * model-checking action (described by a ModelAction object). Must be called
- * from a user-thread context.
- *
- * @param act The current action that will be explored. May be NULL only if
- * trace is exiting via an assertion (see ModelExecution::set_assert and
- * ModelExecution::has_asserted).
- * @return Return the value returned by the current action
- */
-uint64_t ModelChecker::switch_to_master(ModelAction *act)
+/* Swap back to system_context and terminate this execution */
+void ModelChecker::finishRunExecution(Thread *old)
+{
+ scheduler->set_current_thread(NULL);
+
+ /** If we have more executions, we won't make it past this call. */
+ finish_execution(execution_number < params.maxexecutions);
+
+
+ /** We finished the final execution. Print stuff and exit. */
+ model_print("******* Model-checking complete: *******\n");
+ print_stats();
+
+ /* Have the trace analyses dump their output. */
+ for (unsigned int i = 0;i < trace_analyses.size();i++)
+ trace_analyses[i]->finish();
+
+ /* unlink tmp file created by last child process */
+ char filename[256];
+ snprintf_(filename, sizeof(filename), "C11FuzzerTmp%d", getpid());
+ unlink(filename);
+
+ /* Exit. */
+ _Exit(0);
+}
+
+void ModelChecker::consumeAction()
{
- if (forklock) {
+ ModelAction *curr = chosen_thread->get_pending();
+ chosen_thread->set_pending(NULL);
+ chosen_thread = execution->take_step(curr);
+}
+
+/* Allow pending relaxed/release stores or thread actions to perform first */
+void ModelChecker::chooseThread(ModelAction *act, Thread *thr)
+{
+ if (!thread_chosen && act && execution->is_enabled(thr) && (thr->get_state() != THREAD_BLOCKED) ) {
+ if (act->is_write()) {
+ std::memory_order order = act->get_mo();
+ if (order == std::memory_order_relaxed || \
+ order == std::memory_order_release) {
+ chosen_thread = thr;
+ thread_chosen = true;
+ }
+ } else if (act->get_type() == THREAD_CREATE || \
+ act->get_type() == PTHREAD_CREATE || \
+ act->get_type() == THREAD_START || \
+ act->get_type() == THREAD_FINISH) {
+ chosen_thread = thr;
+ thread_chosen = true;
+ }
+ }
+}
+
+uint64_t ModelChecker::switch_thread(ModelAction *act)
+{
+ if (modellock) {
static bool fork_message_printed = false;
if (!fork_message_printed) {
- model_print("Fork handler trying to call into model checker...\n");
+ model_print("Fork handler or dead thread trying to call into model checker...\n");
fork_message_printed = true;
}
delete act;
}
DBG();
Thread *old = thread_current();
- scheduler->set_current_thread(NULL);
+ old->set_state(THREAD_READY);
+
ASSERT(!old->get_pending());
if (inspect_plugin != NULL) {
}
old->set_pending(act);
- if (Thread::swap(old, &system_context) < 0) {
- perror("swap threads");
- exit(EXIT_FAILURE);
- }
- return old->get_return_value();
-}
-static void runChecker() {
- model->run();
- delete model;
-}
-
-void ModelChecker::startChecker() {
- startExecution(get_system_context(), runChecker);
-}
+ if (old->is_waiting_on(old))
+ assert_bug("Deadlock detected (thread %u)", curr_thread_num);
-bool ModelChecker::should_terminate_execution()
-{
- /* Infeasible -> don't take any more steps */
- if (execution->is_infeasible())
- return true;
- else if (execution->isfeasibleprefix() && execution->have_fatal_bug_reports()) {
- execution->set_assert();
- return true;
+ if (act && execution->is_enabled(old) && !execution->check_action_enabled(act)) {
+ scheduler->sleep(old);
}
- return false;
-}
+ chooseThread(act, old);
+
+ curr_thread_num++;
+ Thread* next = getNextThread();
+ if (next != nullptr) {
+ scheduler->set_current_thread(next);
+ if (Thread::swap(old, next) < 0) {
+ perror("swap threads");
+ exit(EXIT_FAILURE);
+ }
+ } else
+ handleChosenThread(old);
-/** @brief Restart ModelChecker upon returning to the run loop of the
- * model checker. */
-void ModelChecker::restart()
-{
- restart_flag = true;
+ return old->get_return_value();
}
-void ModelChecker::do_restart()
+void ModelChecker::handleChosenThread(Thread *old)
{
- restart_flag = false;
- reset_to_initial_state();
- memset(&stats,0,sizeof(struct execution_stats));
- execution_number = 1;
-}
+ if (execution->has_asserted()) {
+ finishRunExecution(old);
+ return;
+ }
+ if (!chosen_thread)
+ chosen_thread = get_next_thread();
+ if (!chosen_thread || chosen_thread->is_model_thread()) {
+ finishRunExecution(old);
+ return;
+ }
+ if (chosen_thread->just_woken_up()) {
+ chosen_thread->set_wakeup_state(false);
+ chosen_thread->set_pending(NULL);
+ chosen_thread = NULL;
+ // Allow this thread to stash the next pending action
+ startRunExecution(old);
+ return;
+ }
-void ModelChecker::startMainThread() {
- init_thread->set_state(THREAD_RUNNING);
- scheduler->set_current_thread(init_thread);
- thread_startup();
-}
+ // Consume the next action for a Thread
+ consumeAction();
-static bool is_nonsc_write(const ModelAction *act) {
- if (act->get_type() == ATOMIC_WRITE) {
- std::memory_order order = act->get_mo();
- switch(order) {
- case std::memory_order_relaxed:
- case std::memory_order_release:
- return true;
- default:
- return false;
- }
- }
- return false;
+ if (should_terminate_execution()) {
+ finishRunExecution(old);
+ return;
+ } else
+ startRunExecution(old);
}
-/** @brief Run ModelChecker for the user program */
-void ModelChecker::run()
-{
+void ModelChecker::startChecker() {
+ startExecution();
//Need to initial random number generator state to avoid resets on rollback
- char random_state[256];
initstate(423121, random_state, sizeof(random_state));
- for(int exec = 0;exec < params.maxexecutions;exec++) {
- Thread * t = init_thread;
-
- do {
- /*
- * Stash next pending action(s) for thread(s). There
- * should only need to stash one thread's action--the
- * thread which just took a step--plus the first step
- * for any newly-created thread
- */
- ModelAction * pending;
- for (unsigned int i = 0;i < get_num_threads();i++) {
- thread_id_t tid = int_to_id(i);
- Thread *thr = get_thread(tid);
- if (!thr->is_model_thread() && !thr->is_complete() && ((!(pending=thr->get_pending())) || is_nonsc_write(pending)) ) {
- switch_from_master(thr); // L: context swapped, and action type of thr changed.
- if (thr->is_waiting_on(thr))
- assert_bug("Deadlock detected (thread %u)", i);
- }
- }
+ snapshot = take_snapshot();
- /* Don't schedule threads which should be disabled */
- for (unsigned int i = 0;i < get_num_threads();i++) {
- Thread *th = get_thread(int_to_id(i));
- ModelAction *act = th->get_pending();
- if (act && execution->is_enabled(th) && !execution->check_action_enabled(act)) {
- scheduler->sleep(th);
- }
- }
+ //reset random number generator state
+ setstate(random_state);
- for (unsigned int i = 1;i < get_num_threads();i++) {
- Thread *th = get_thread(int_to_id(i));
- ModelAction *act = th->get_pending();
- if (act && execution->is_enabled(th) && (th->get_state() != THREAD_BLOCKED) ) {
- if (act->is_write()) {
- std::memory_order order = act->get_mo();
- if (order == std::memory_order_relaxed || \
- order == std::memory_order_release) {
- t = th;
- break;
- }
- } else if (act->get_type() == THREAD_CREATE || \
- act->get_type() == PTHREAD_CREATE || \
- act->get_type() == THREAD_START || \
- act->get_type() == THREAD_FINISH) {
- t = th;
- break;
- }
- }
- }
+ install_trace_analyses(get_execution());
+ redirect_output();
+ initMainThread();
+}
- /* Catch assertions from prior take_step or from
- * between-ModelAction bugs (e.g., data races) */
-
- if (execution->has_asserted())
- break;
- if (!t)
- t = get_next_thread();
- if (!t || t->is_model_thread())
- break;
-
- /* Consume the next action for a Thread */
- ModelAction *curr = t->get_pending();
- t->set_pending(NULL);
- t = execution->take_step(curr);
- } while (!should_terminate_execution());
- next_execution();
- //restore random number generator state after rollback
- setstate(random_state);
+bool ModelChecker::should_terminate_execution()
+{
+ if (execution->have_bug_reports()) {
+ execution->set_assert();
+ return true;
+ } else if (execution->isFinished()) {
+ return true;
}
-
- model_print("******* Model-checking complete: *******\n");
- print_stats();
-
- /* Have the trace analyses dump their output. */
- for (unsigned int i = 0;i < trace_analyses.size();i++)
- trace_analyses[i]->finish();
+ return false;
}
projects / c11tester.git / blobdiff