Merge pull request #198 from prattmic/cleanup

all: cleanup executor/ipc interaction

3 files changed, 17 insertions, 20 deletions

diff --git a/executor/executor.cc b/executor/executor.cc
index cb31e0697..044410792 100644
--- a/executor/executor.cc
+++ b/executor/executor.cc
@@ -226,7 +226,8 @@ int main(int argc, char** argv)
 	// ptrace(PTRACE_SEIZE, 1, 0, 0x100040)
 	// This is unfortunate, but I don't have a better solution than ignoring it for now.
 	exitf("loop exited with status %d", status);
-	return 0;
+	// Unreachable.
+	return 1;
 }
 
 void loop()
diff --git a/ipc/ipc.go b/ipc/ipc.go
index ce951aab6..5d579b479 100644
--- a/ipc/ipc.go
+++ b/ipc/ipc.go
@@ -617,36 +617,28 @@ func (c *command) exec(opts *ExecOpts) (output []byte, failed, hanged, restart b
 		}
 		status = int(reply[0])
 		if status == 0 {
+			// Program was OK.
 			<-hang
 			return
 		}
 		// Executor writes magic values into the pipe before exiting,
 		// so proceed with killing and joining it.
-		status = int(reply[0])
 	}
-	err0 = fmt.Errorf("executor did not answer")
 	c.abort()
 	output = <-c.readDone
-	if err := c.wait(); <-hang && err != nil {
+	if err := c.wait(); <-hang {
 		hanged = true
+		// In all likelihood, this will be duplicated by the default
+		// case below, but that's fine.
 		output = append(output, []byte(err.Error())...)
 		output = append(output, '\n')
 	}
-	switch status {
-	case statusFail, statusError, statusRetry:
-	default:
-		if c.cmd.ProcessState != nil {
-			sys := c.cmd.ProcessState.Sys()
-			if ws, ok := sys.(syscall.WaitStatus); ok {
-				status = ws.ExitStatus()
-			}
-		}
-	}
 	// Handle magic values returned by executor.
 	switch status {
 	case statusFail:
 		err0 = ExecutorFailure(fmt.Sprintf("executor failed: %s", output))
 	case statusError:
+		err0 = fmt.Errorf("executor detected kernel bug")
 		failed = true
 	case statusRetry:
 		// This is a temporal error (ENOMEM) or an unfortunate
@@ -656,6 +648,14 @@ func (c *command) exec(opts *ExecOpts) (output []byte, failed, hanged, restart b
 		err0 = nil
 		hanged = false
 		restart = true
+	default:
+		// Failed to get a valid (or perhaps any) status from the
+		// executor.
+		//
+		// Once the executor is serving the status is always written to
+		// the pipe, so we don't bother to check the specific exit
+		// codes from wait.
+		err0 = fmt.Errorf("invalid (or no) executor status received: %d, executor exit: %s", status, c.cmd.ProcessState)
 	}
 	return
 }
diff --git a/tools/syz-stress/stress.go b/tools/syz-stress/stress.go
index 5885e233d..4cf8d931f 100644
--- a/tools/syz-stress/stress.go
+++ b/tools/syz-stress/stress.go
@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"math/rand"
 	"os"
-	"regexp"
 	"runtime"
 	"sync"
 	"sync/atomic"
@@ -30,8 +29,6 @@ var (
 	flagLogProg  = flag.Bool("logprog", false, "print programs before execution")
 	flagGenerate = flag.Bool("generate", true, "generate new programs, otherwise only mutate corpus")
 
-	failedRe = regexp.MustCompile("runtime error: |panic: |Panic: ")
-
 	statExec uint64
 	gate     *ipc.Gate
 )
@@ -105,11 +102,10 @@ func execute(pid int, env *ipc.Env, p *prog.Prog) {
 	if err != nil {
 		fmt.Printf("failed to execute executor: %v\n", err)
 	}
-	paniced := failedRe.Match(output)
-	if failed || hanged || paniced || err != nil {
+	if failed || hanged || err != nil {
 		fmt.Printf("PROGRAM:\n%s\n", p.Serialize())
 	}
-	if failed || hanged || paniced || err != nil || *flagOutput {
+	if failed || hanged || err != nil || *flagOutput {
 		os.Stdout.Write(output)
 	}
 }