tools/syz-minconfig: add tool

syz-minconfig is a tool for manual checking of config minimization functionality in pkg/kconfig/minimize.go.
Example use:
$ go run tools/syz-minconfig/minconfig.go -sourcedir /src/linux -configs CAIF_NETDEV,CAIF_USB \
	-base dashboard/config/linux/upstream-kasan-base.config \
	-full dashboard/config/linux/upstream-kasan.config \

Update #2171

1 files changed, 59 insertions, 0 deletions

diff --git a/tools/syz-minconfig/minconfig.go b/tools/syz-minconfig/minconfig.go
new file mode 100644
index 000000000..b68c183eb
--- /dev/null
+++ b/tools/syz-minconfig/minconfig.go
@@ -0,0 +1,59 @@
+// Copyright 2020 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.
+
+// syz-minconfig is a tool for manual checking of config minimization functionality in pkg/kconfig/minimize.go.
+// Example use:
+// $ go run tools/syz-minconfig/minconfig.go -sourcedir /src/linux -configs CAIF_NETDEV,CAIF_USB \
+//	-base dashboard/config/linux/upstream-kasan-base.config \
+//	-full dashboard/config/linux/upstream-kasan.config \
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/google/syzkaller/pkg/kconfig"
+)
+
+func main() {
+	var (
+		flagSourceDir = flag.String("sourcedir", "", "kernel sources dir")
+		flagBase      = flag.String("base", "", "baseline config")
+		flagFull      = flag.String("full", "", "full config")
+		flagConfigs   = flag.String("configs", "", "comma-separated list of configs for the crash predicate")
+	)
+	flag.Parse()
+	kconf, err := kconfig.Parse(filepath.Join(*flagSourceDir, "Kconfig"))
+	if err != nil {
+		failf("%v", err)
+	}
+	base, err := kconfig.ParseConfig(*flagBase)
+	if err != nil {
+		failf("%v", err)
+	}
+	full, err := kconfig.ParseConfig(*flagFull)
+	if err != nil {
+		failf("%v", err)
+	}
+	pred := func(candidate *kconfig.ConfigFile) (bool, error) {
+		for _, cfg := range strings.Split(*flagConfigs, ",") {
+			if candidate.Value(cfg) == kconfig.No {
+				return false, nil
+			}
+		}
+		return true, nil
+	}
+	res, err := kconf.Minimize(base, full, pred, os.Stderr)
+	if err != nil {
+		failf("%v", err)
+	}
+	os.Stdout.Write(res.Serialize())
+}
+
+func failf(msg string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, msg+"\n", args...)
+	os.Exit(1)
+}