tools/syz-upgrade: helper tool for corpus format upgrades

Makefile

@@ -5,7 +5,7 @@
 
 all: manager fuzzer executor
 
-all-tools: execprog mutate prog2c stress repro
+all-tools: execprog mutate prog2c stress repro upgrade
 
 manager:
 	go build -o ./bin/syz-manager github.com/google/syzkaller/syz-manager
@@ -31,6 +31,9 @@ prog2c:
 stress:
 	go build -o ./bin/syz-stress github.com/google/syzkaller/tools/syz-stress
 
+upgrade:
+	go build -o ./bin/syz-upgrade github.com/google/syzkaller/tools/syz-upgrade
+
 generate:
 	go run sysgen/*.go -linux=$(LINUX) sys/sys.txt
 

tools/syz-upgrade/upgrade.go

@@ -0,0 +1,59 @@
+// Copyright 2015 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+// upgrade upgrades corpus from an old format to a new format.
+// Upgrade is not fully automatic. You need to update prog.Serialize.
+// Run the tool. Then update prog.Deserialize. And run the tool again that
+// the corpus is not changed this time.
+package main
+
+import (
+	"bytes"
+	"crypto/sha1"
+	"encoding/hex"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/google/syzkaller/prog"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fatalf("usage: syz-upgrage corpus_dir")
+	}
+	files, err := ioutil.ReadDir(os.Args[1])
+	if err != nil {
+		fatalf("failed to read corpus dir: %v", err)
+	}
+	for _, f := range files {
+		fname := filepath.Join(os.Args[1], f.Name())
+		data, err := ioutil.ReadFile(fname)
+		if err != nil {
+			fatalf("failed to read program: %v", err)
+		}
+		p, err := prog.Deserialize(data)
+		if err != nil {
+			fatalf("failed to deserialize program: %v", err)
+		}
+		data1 := p.Serialize()
+		if bytes.Equal(data, data1) {
+			continue
+		}
+		fmt.Printf("upgrading:\n%s\nto:\n%s\n\n", data, data1)
+		hash := sha1.Sum(data1)
+		fname1 := filepath.Join(os.Args[1], hex.EncodeToString(hash[:]))
+		if err := ioutil.WriteFile(fname1, data1, 0640); err != nil {
+			fatalf("failed to write program: %v", err)
+		}
+		if err := os.Remove(fname); err != nil {
+			fatalf("failed to remove program: %v", err)
+		}
+	}
+}
+
+func fatalf(msg string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, msg+"\n", args...)
+	os.Exit(1)
+}