vm/proxyapp: configure proxyApp log output (#3459)

2 files changed, 4 insertions, 2 deletions

diff --git a/vm/proxyapp/init.go b/vm/proxyapp/init.go
index 17db527f9..538cadf6f 100644
--- a/vm/proxyapp/init.go
+++ b/vm/proxyapp/init.go
@@ -8,6 +8,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"os"
 	"time"
 
 	"github.com/google/syzkaller/pkg/config"
@@ -19,6 +20,7 @@ func makeDefaultParams() *proxyAppParams {
 	return &proxyAppParams{
 		CommandRunner:  osutilCommandContext,
 		InitRetryDelay: 10 * time.Second,
+		LogOutput:      os.Stdout,
 	}
 }
 
@@ -35,6 +37,7 @@ func init() {
 type proxyAppParams struct {
 	CommandRunner  func(context.Context, string, ...string) subProcessCmd
 	InitRetryDelay time.Duration
+	LogOutput      io.Writer
 }
 
 func osutilCommandContext(ctx context.Context, bin string, args ...string) subProcessCmd {
diff --git a/vm/proxyapp/proxyappclient.go b/vm/proxyapp/proxyappclient.go
index d51039456..b17e045d0 100644
--- a/vm/proxyapp/proxyappclient.go
+++ b/vm/proxyapp/proxyappclient.go
@@ -11,7 +11,6 @@ import (
 	"io"
 	"net/rpc"
 	"net/rpc/jsonrpc"
-	"os"
 	"sync"
 	"time"
 
@@ -172,7 +171,7 @@ func runProxyApp(params *proxyAppParams, cmd string) (*ProxyApp, error) {
 	onTerminated := make(chan bool, 1)
 
 	go func() {
-		io.Copy(os.Stdout, subprocessLogs)
+		io.Copy(params.LogOutput, subprocessLogs)
 		if err := subProcess.Wait(); err != nil {
 			log.Logf(0, "failed to Wait() subprocess: %v", err)
 		}