vm: fix "kill fuzzer on first kernel bug"

The problem with that commit is that for GCE implementation
we immidiately kill console connection too when receive diagnose signal.
This leads to truncated output.

2 files changed, 23 insertions, 28 deletions

diff --git a/vm/gce/gce.go b/vm/gce/gce.go
index 1bdf83444..cc2cd62cd 100644
--- a/vm/gce/gce.go
+++ b/vm/gce/gce.go
@@ -49,17 +49,16 @@ type Pool struct {
 }
 
 type instance struct {
-	env      *vmimpl.Env
-	cfg      *Config
-	GCE      *gce.Context
-	debug    bool
-	name     string
-	ip       string
-	gceKey   string // per-instance private ssh key associated with the instance
-	sshKey   string // ssh key
-	sshUser  string
-	closed   chan bool
-	diagnose chan bool
+	env     *vmimpl.Env
+	cfg     *Config
+	GCE     *gce.Context
+	debug   bool
+	name    string
+	ip      string
+	gceKey  string // per-instance private ssh key associated with the instance
+	sshKey  string // ssh key
+	sshUser string
+	closed  chan bool
 }
 
 func ctor(env *vmimpl.Env) (vmimpl.Pool, error) {
@@ -172,17 +171,16 @@ func (pool *Pool) Create(workdir string, index int) (vmimpl.Instance, error) {
 	}
 	ok = true
 	inst := &instance{
-		env:      pool.env,
-		cfg:      pool.cfg,
-		debug:    pool.env.Debug,
-		GCE:      pool.GCE,
-		name:     name,
-		ip:       ip,
-		gceKey:   gceKey,
-		sshKey:   sshKey,
-		sshUser:  sshUser,
-		closed:   make(chan bool),
-		diagnose: make(chan bool, 1),
+		env:     pool.env,
+		cfg:     pool.cfg,
+		debug:   pool.env.Debug,
+		GCE:     pool.GCE,
+		name:    name,
+		ip:      ip,
+		gceKey:  gceKey,
+		sshKey:  sshKey,
+		sshUser: sshUser,
+		closed:  make(chan bool),
 	}
 	return inst, nil
 }
@@ -316,6 +314,7 @@ func (inst *instance) Run(timeout time.Duration, stop <-chan bool, command strin
 	}
 
 	go func() {
+	retry:
 		select {
 		case <-time.After(timeout):
 			signal(vmimpl.ErrTimeout)
@@ -323,8 +322,6 @@ func (inst *instance) Run(timeout time.Duration, stop <-chan bool, command strin
 			signal(vmimpl.ErrTimeout)
 		case <-inst.closed:
 			signal(fmt.Errorf("instance closed"))
-		case <-inst.diagnose:
-			ssh.Process.Kill()
 		case err := <-merger.Err:
 			con.Process.Kill()
 			ssh.Process.Kill()
@@ -360,10 +357,6 @@ func (inst *instance) Run(timeout time.Duration, stop <-chan bool, command strin
 }
 
 func (inst *instance) Diagnose() bool {
-	select {
-	case inst.diagnose <- true:
-	default:
-	}
 	return false
 }
 
diff --git a/vm/qemu/qemu.go b/vm/qemu/qemu.go
index 6ba33c0ad..501a6b02b 100644
--- a/vm/qemu/qemu.go
+++ b/vm/qemu/qemu.go
@@ -476,6 +476,7 @@ func (inst *instance) Run(timeout time.Duration, stop <-chan bool, command strin
 	}
 
 	go func() {
+	retry:
 		select {
 		case <-time.After(timeout):
 			signal(vmimpl.ErrTimeout)
@@ -483,6 +484,7 @@ func (inst *instance) Run(timeout time.Duration, stop <-chan bool, command strin
 			signal(vmimpl.ErrTimeout)
 		case <-inst.diagnose:
 			cmd.Process.Kill()
+			goto retry
 		case err := <-inst.merger.Err:
 			cmd.Process.Kill()
 			if cmdErr := cmd.Wait(); cmdErr == nil {