pkg/vcs: disable Linux kernel configs based on crash.Type

More sanitizers means longer compilation times, more flakiness and risks
of failures due to bugs in sanitizers themselves.

If the crash type is known, determine the sanitizer that detected the
problem and disable everything else.

1 files changed, 93 insertions, 0 deletions

diff --git a/pkg/vcs/linux_configs_test.go b/pkg/vcs/linux_configs_test.go
new file mode 100644
index 000000000..6ea95645f
--- /dev/null
+++ b/pkg/vcs/linux_configs_test.go
@@ -0,0 +1,93 @@
+// Copyright 2023 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.
+
+package vcs
+
+import (
+	"testing"
+
+	"github.com/google/syzkaller/pkg/debugtracer"
+	"github.com/google/syzkaller/pkg/kconfig"
+	"github.com/google/syzkaller/pkg/report/crash"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDropLinuxSanitizerConfigs(t *testing.T) {
+	tests := []struct {
+		name  string
+		types []crash.Type
+		test  func(*testing.T, *kconfig.ConfigFile)
+	}{
+		{
+			name:  "warning",
+			types: []crash.Type{crash.Warning},
+			test: func(t *testing.T, cf *kconfig.ConfigFile) {
+				assertConfigs(t, cf, "BUG")
+				assert.Equal(t,
+					`"param1=a param2=b rcupdate.rcu_cpu_stall_suppress=1"`,
+					cf.Value("CMDLINE"),
+				)
+			},
+		},
+		{
+			name:  "kasan bug",
+			types: []crash.Type{crash.KASAN},
+			test: func(t *testing.T, cf *kconfig.ConfigFile) {
+				assertConfigs(t, cf, "KASAN")
+			},
+		},
+		{
+			name:  "warning & kasan bug",
+			types: []crash.Type{crash.Warning, crash.KASAN},
+			test: func(t *testing.T, cf *kconfig.ConfigFile) {
+				assertConfigs(t, cf, "KASAN", "BUG")
+			},
+		},
+		{
+			name:  "lockdep",
+			types: []crash.Type{crash.LockdepBug},
+			test: func(t *testing.T, cf *kconfig.ConfigFile) {
+				assertConfigs(t, cf, "LOCKDEP")
+			},
+		},
+		{
+			name:  "rcu stall",
+			types: []crash.Type{crash.Hang},
+			test: func(t *testing.T, cf *kconfig.ConfigFile) {
+				assertConfigs(t, cf, "RCU_STALL_COMMON")
+				assert.Equal(t, `"param1=a param2=b"`, cf.Value("CMDLINE"))
+			},
+		},
+	}
+
+	const base = `
+CONFIG_CMDLINE="param1=a param2=b"
+CONFIG_BUG=y
+CONFIG_KASAN=y
+CONFIG_LOCKDEP=y
+CONFIG_RCU_STALL_COMMON=y
+CONFIG_UBSAN=y
+CONFIG_DEBUG_ATOMIC_SLEEP=y
+`
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			conf, err := kconfig.ParseConfigData([]byte(base), "base")
+			if err != nil {
+				t.Fatal(err)
+			}
+			setLinuxSanitizerConfigs(conf, test.types, &debugtracer.NullTracer{})
+			test.test(t, conf)
+		})
+	}
+}
+
+func assertConfigs(t *testing.T, cf *kconfig.ConfigFile, names ...string) {
+	var setConfigs []string
+	for _, name := range names {
+		if cf.Value(name) == kconfig.Yes {
+			setConfigs = append(setConfigs, name)
+		}
+	}
+	assert.ElementsMatch(t, setConfigs, names)
+}