func (mgr *Manager) saveRepro(crash *Crash, res *repro.Result) {
sig := hash.Hash([]byte(crash.desc))
dir := filepath.Join(mgr.crashdir, sig.String())
if res == nil {
for i := 0; i < maxReproAttempts; i++ {
name := filepath.Join(dir, fmt.Sprintf("repro%v", i))
if _, err := os.Stat(name); err != nil {
ioutil.WriteFile(name, nil, 0660)
break
}
}
return
}
opts := fmt.Sprintf("# %+v\n", res.Opts)
prog := res.Prog.Serialize()
ioutil.WriteFile(filepath.Join(dir, "repro.prog"), append([]byte(opts), prog...), 0660)
if len(mgr.cfg.Tag) > 0 {
ioutil.WriteFile(filepath.Join(dir, "repro.tag"), []byte(mgr.cfg.Tag), 0660)
}
if len(crash.text) > 0 {
ioutil.WriteFile(filepath.Join(dir, "repro.report"), []byte(crash.text), 0660)
}
if res.CRepro {
cprog, err := csource.Write(res.Prog, res.Opts)
if err == nil {
formatted, err := csource.Format(cprog)
if err == nil {
cprog = formatted
}
ioutil.WriteFile(filepath.Join(dir, "repro.cprog"), cprog, 0660)
} else {
Logf(0, "failed to write C source: %v", err)
}
}
}
func main() {
flag.Parse()
if len(flag.Args()) != 1 {
fmt.Fprintf(os.Stderr, "usage: prog2c [-threaded [-collide]] prog_file\n")
os.Exit(1)
}
data, err := ioutil.ReadFile(flag.Args()[0])
if err != nil {
fmt.Fprintf(os.Stderr, "failed to read prog file: %v\n", err)
os.Exit(1)
}
p, err := prog.Deserialize(data)
if err != nil {
fmt.Fprintf(os.Stderr, "failed to deserialize the program: %v\n", err)
os.Exit(1)
}
opts := csource.Options{
Threaded: *flagThreaded,
Collide: *flagCollide,
}
src := csource.Write(p, opts)
if formatted, err := csource.Format(src); err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
} else {
src = formatted
}
os.Stdout.Write(src)
}
func main() {
os.Args = append(append([]string{}, os.Args[0], "-v=10"), os.Args[1:]...)
flag.Parse()
cfg, _, err := config.Parse(*flagConfig)
if err != nil {
Fatalf("%v", err)
}
if *flagCount > 0 {
cfg.Count = *flagCount
}
if cfg.Count > 4 {
cfg.Count = 4
}
if len(flag.Args()) != 1 {
Fatalf("usage: syz-repro -config=config.file execution.log")
}
data, err := ioutil.ReadFile(flag.Args()[0])
if err != nil {
Fatalf("failed to open log file: %v", err)
}
vmIndexes := make([]int, cfg.Count)
for i := range vmIndexes {
vmIndexes[i] = i
}
go func() {
c := make(chan os.Signal, 2)
signal.Notify(c, syscall.SIGINT)
<-c
close(vm.Shutdown)
Logf(-1, "shutting down...")
<-c
Fatalf("terminating")
}()
res, err := repro.Run(data, cfg, vmIndexes)
if err != nil {
Logf(0, "reproduction failed: %v", err)
}
if res == nil {
return
}
fmt.Printf("opts: %+v crepro: %v\n\n", res.Opts, res.CRepro)
fmt.Printf("%s\n", res.Prog.Serialize())
if res.CRepro {
src, err := csource.Write(res.Prog, res.Opts)
if err != nil {
Fatalf("failed to generate C repro: %v", err)
}
if formatted, err := csource.Format(src); err == nil {
src = formatted
}
fmt.Printf("%s\n", src)
}
}
func main() {
flag.Parse()
if *flagProg == "" {
flag.PrintDefaults()
os.Exit(1)
}
data, err := ioutil.ReadFile(*flagProg)
if err != nil {
fmt.Fprintf(os.Stderr, "failed to read prog file: %v\n", err)
os.Exit(1)
}
p, err := prog.Deserialize(data)
if err != nil {
fmt.Fprintf(os.Stderr, "failed to deserialize the program: %v\n", err)
os.Exit(1)
}
opts := csource.Options{
Threaded: *flagThreaded,
Collide: *flagCollide,
Repeat: *flagRepeat,
Procs: *flagProcs,
Sandbox: *flagSandbox,
Repro: false,
}
src, err := csource.Write(p, opts)
if err != nil {
fmt.Fprintf(os.Stderr, "failed to generate C spurce: %v\n", err)
os.Exit(1)
}
if formatted, err := csource.Format(src); err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
} else {
src = formatted
}
os.Stdout.Write(src)
}
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)
}
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
}
func TestCompare(t *testing.T) {
t.Skip("flaky")
bin := buildExecutor(t)
defer os.Remove(bin)
// Sequence of syscalls that statically linked libc produces on startup.
rawTracePrefix := []string{"execve", "uname", "brk", "brk", "arch_prctl",
"readlink", "brk", "brk", "access"}
executorTracePrefix := []string{"execve", "uname", "brk", "brk", "arch_prctl",
"set_tid_address", "set_robust_list", "futex", "rt_sigaction", "rt_sigaction",
"rt_sigprocmask", "getrlimit", "readlink", "brk", "brk", "access", "mmap", "mmap"}
// These calls produce non-deterministic results, ignore them.
nondet := []string{"getrusage", "msgget", "msgrcv", "msgsnd", "shmget", "semat", "io_setup", "getpgrp",
"getpid", "getpgid", "getppid", "setsid", "ppoll", "keyctl", "ioprio_get",
"move_pages", "kcmp"}
env1, err := MakeEnv(bin, timeout, FlagStrace)
if err != nil {
t.Fatalf("failed to create env: %v", err)
}
defer env1.Close()
rs, iters := initTest(t)
for i := 0; i < iters; i++ {
p := prog.Generate(rs, 10, nil)
_, strace1, _, _, _, _, err := env1.Exec(p)
if err != nil {
t.Fatalf("failed to run executor: %v", err)
}
src := csource.Write(p, csource.Options{})
cprog := buildSource(t, src)
defer os.Remove(cprog)
env2, err := MakeEnv(cprog, timeout, FlagStrace)
if err != nil {
t.Fatalf("failed to create env: %v", err)
}
defer env2.Close() // yes, that's defer in a loop
_, strace2, _, _, _, _, err := env2.Exec(nil)
if err != nil {
t.Fatalf("failed to run c binary: %v", err)
}
stripPrefix := func(data []byte, prefix []string) string {
prefix0 := prefix
buf := new(bytes.Buffer)
s := bufio.NewScanner(bytes.NewReader(data))
for s.Scan() {
if strings.HasPrefix(s.Text(), "--- SIG") {
// Signal parameters can contain pid and pc.
continue
}
if len(prefix) == 0 {
skip := false
for _, c := range nondet {
if strings.HasPrefix(s.Text(), c) {
skip = true
break
}
}
if skip {
continue
}
buf.WriteString(s.Text())
buf.Write([]byte{'\n'})
continue
}
if !strings.HasPrefix(s.Text(), prefix[0]) {
t.Fatalf("strace output does not start with expected prefix\ngot:\n%s\nexpect prefix: %+v\ncurrent call: %v", data, prefix0, prefix[0])
}
prefix = prefix[1:]
}
if err := s.Err(); err != nil {
t.Fatalf("failed to scan strace output: %v", err)
}
return buf.String()
}
s1 := stripPrefix(strace1, executorTracePrefix)
s2 := stripPrefix(strace2, rawTracePrefix)
if s1 == "" || s1 != s2 {
t.Logf("program:\n%s\n", p.Serialize())
t.Fatalf("strace output differs:\n%s\n\n\n%s\n", s1, s2)
}
}
}