Exemplo n.º 1
0
func repro(cfg *config.Config, entries []*prog.LogEntry, crashLoc []int) {
	// Cut programs that were executed after crash.
	for i, ent := range entries {
		if ent.Start > crashLoc[0] {
			entries = entries[:i]
			break
		}
	}
	// Extract last program on every proc.
	procs := make(map[int]int)
	for i, ent := range entries {
		procs[ent.Proc] = i
	}
	var indices []int
	for _, idx := range procs {
		indices = append(indices, idx)
	}
	sort.Ints(indices)
	var suspected []*prog.LogEntry
	for i := len(indices) - 1; i >= 0; i-- {
		suspected = append(suspected, entries[indices[i]])
	}
	// Execute the suspected programs.
	log.Printf("the suspected programs are:")
	for _, ent := range suspected {
		log.Printf("on proc %v:\n%s\n", ent.Proc, ent.P.Serialize())
	}
	var p *prog.Prog
	multiplier := 1
	for ; p == nil && multiplier <= 100; multiplier *= 10 {
		for _, ent := range suspected {
			if testProg(cfg, ent.P, multiplier, true, true) {
				p = ent.P
				break
			}
		}
	}
	if p == nil {
		log.Printf("no program crashed")
		return
	}
	log.Printf("minimizing program")

	p, _ = prog.Minimize(p, -1, func(p1 *prog.Prog, callIndex int) bool {
		return testProg(cfg, p1, multiplier, true, true)
	})

	opts := csource.Options{
		Threaded: true,
		Collide:  true,
	}
	if testProg(cfg, p, multiplier, true, false) {
		opts.Collide = false
		if testProg(cfg, p, multiplier, false, false) {
			opts.Threaded = false
		}
	}

	src := csource.Write(p, opts)
	log.Printf("C source:\n%s\n", src)
	srcf, err := fileutil.WriteTempFile(src)
	if err != nil {
		log.Fatalf("%v", err)
	}
	bin, err := csource.Build(srcf)
	if err != nil {
		log.Fatalf("%v", err)
	}
	defer os.Remove(bin)
	testBin(cfg, bin)
}
Exemplo n.º 2
0
func (ctx *context) repro(entries []*prog.LogEntry, crashStart int) (*Result, error) {
	// Cut programs that were executed after crash.
	for i, ent := range entries {
		if ent.Start > crashStart {
			entries = entries[:i]
			break
		}
	}
	// Extract last program on every proc.
	procs := make(map[int]int)
	for i, ent := range entries {
		procs[ent.Proc] = i
	}
	var indices []int
	for _, idx := range procs {
		indices = append(indices, idx)
	}
	sort.Ints(indices)
	var suspected []*prog.LogEntry
	for i := len(indices) - 1; i >= 0; i-- {
		suspected = append(suspected, entries[indices[i]])
	}
	Logf(2, "reproducing crash '%v': suspecting %v programs", ctx.crashDesc, len(suspected))
	opts := csource.Options{
		Threaded: true,
		Collide:  true,
		Repeat:   true,
		Procs:    ctx.cfg.Procs,
		Sandbox:  ctx.cfg.Sandbox,
		Repro:    true,
	}
	// Execute the suspected programs.
	// We first try to execute each program for 10 seconds, that should detect simple crashes
	// (i.e. no races and no hangs). Then we execute each program for 5 minutes
	// to catch races and hangs. Note that the max duration must be larger than
	// hang/no output detection duration in vm.MonitorExecution, which is currently set to 3 mins.
	var res *Result
	var duration time.Duration
	for _, dur := range []time.Duration{10 * time.Second, 5 * time.Minute} {
		for _, ent := range suspected {
			crashed, err := ctx.testProg(ent.P, dur, opts, true)
			if err != nil {
				return nil, err
			}
			if crashed {
				res = &Result{
					Prog: ent.P,
					Opts: opts,
				}
				duration = dur * 3 / 2
				break
			}
		}
		if res != nil {
			break
		}
	}
	if res == nil {
		Logf(0, "reproducing crash '%v': no program crashed", ctx.crashDesc)
		return nil, nil
	}
	defer func() {
		res.Opts.Repro = false
	}()

	Logf(2, "reproducing crash '%v': minimizing guilty program", ctx.crashDesc)
	res.Prog, _ = prog.Minimize(res.Prog, -1, func(p1 *prog.Prog, callIndex int) bool {
		crashed, err := ctx.testProg(p1, duration, res.Opts, false)
		if err != nil {
			Logf(1, "reproducing crash '%v': minimization failed with %v", ctx.crashDesc, err)
			return false
		}
		return crashed
	}, true)

	// Try to "minimize" threaded/collide/sandbox/etc to find simpler reproducer.
	opts = res.Opts
	opts.Collide = false
	crashed, err := ctx.testProg(res.Prog, duration, opts, false)
	if err != nil {
		return res, err
	}
	if crashed {
		res.Opts = opts
		opts.Threaded = false
		crashed, err := ctx.testProg(res.Prog, duration, opts, false)
		if err != nil {
			return res, err
		}
		if crashed {
			res.Opts = opts
		}
	}
	if res.Opts.Sandbox == "namespace" {
		opts = res.Opts
		opts.Sandbox = "none"
		crashed, err := ctx.testProg(res.Prog, duration, opts, false)
		if err != nil {
			return res, err
		}
		if crashed {
			res.Opts = opts
		}
	}
	if res.Opts.Procs > 1 {
		opts = res.Opts
		opts.Procs = 1
		crashed, err := ctx.testProg(res.Prog, duration, opts, false)
		if err != nil {
			return res, err
		}
		if crashed {
			res.Opts = opts
		}
	}
	if res.Opts.Repeat {
		opts = res.Opts
		opts.Repeat = false
		crashed, err := ctx.testProg(res.Prog, duration, opts, false)
		if err != nil {
			return res, err
		}
		if crashed {
			res.Opts = opts
		}
	}

	src, err := csource.Write(res.Prog, res.Opts)
	if err != nil {
		return res, err
	}
	srcf, err := fileutil.WriteTempFile(src)
	if err != nil {
		return res, err
	}
	bin, err := csource.Build(srcf)
	if err != nil {
		return res, err
	}
	defer os.Remove(bin)
	crashed, err = ctx.testBin(bin, duration, false)
	if err != nil {
		return res, err
	}
	res.CRepro = crashed
	return res, nil
}