Determine GC type based on BUILT_KERNEL_VERSION_FILE.
How it works:
1. build/make/core/Makefile generates a txt file with the kernel
version, which is taken from an explicit BOARD_KERNEL_VERSION value,
or extracted from the kernel image on the source tree, or extracted
from the kernel image extracted from the prebuilt boot.img.
The file is saved at
$ANDROID_PRODUCT_OUT/obj/PACKAGING/check_vintf_all_intermediates/kernel_version.txt.
2. If PRODUCT_ENABLE_UFFD_GC is "default", meaning the GC type needs to
be determined by the kernel version, build/make/core/Makefile copies
kernel_version.txt to
out/soong/dexpreopt/kernel_version_for_uffd_gc.txt.
3. build/soong/dexpreopt/config.go writes the the UFFD GC flag to
out/soong/dexpreopt/uffd_gc_flag.txt. The flag is determined by an
explicit PRODUCT_ENABLE_UFFD_GC value or by contruct_uffd_gc_flag.py,
which reads kernel_version_for_uffd_gc.txt and determines the flag
accordingly.
4. dex2oat takes the UFFD GC flag from uffd_gc_flag.txt.
5. post_process_props.py mangles ro.dalvik.vm.enable_uffd_gc based on
the same logic.
Bug: 321751629
Bug: 319554951
Bug: 318763448
Bug: 319648491
Test: m --no-skip-soong-tests nothing
Test: atest uffd_gc_utils_test
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=default m` for device with no
UFFD support -
1. Check the existence of `-Xgc:CMC` in
out/soong/dexpreopt_arm64/dex_bootjars/android/system/framework/arm64/boot.invocation
(dex2oat invocation for a boot image)
2. Check the existence of `-Xgc:CMC` in
out/soong/.intermediates/packages/apps/Settings/Settings/android_common/dexpreopt/Settings/oat/arm64/package.invocation
(dex2oat invocation for an app defined in .bp)
3. Check the existence of `-Xgc:CMC` in
$ANDROID_PRODUCT_OUT/obj/APPS/Dialer_intermediates/oat/arm64/package.invocation
(dex2oat invocation for an app defined in .mk)
4. Check the value of ro.dalvik.vm.enable_uffd_gc in
$ANDROID_PRODUCT_OUT/product/etc/build.prop
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=default m` for device with
UFFD support, and do the steps above.
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=true m`, and do the steps
above.
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=false m`, and do the steps
above.
Change-Id: I035ad32233e49e2a30ce11f6c7c318a648511ef8
diff --git a/apex/dexpreopt_bootjars_test.go b/apex/dexpreopt_bootjars_test.go
index d9ab8fa..7a17f50 100644
--- a/apex/dexpreopt_bootjars_test.go
+++ b/apex/dexpreopt_bootjars_test.go
@@ -164,6 +164,7 @@
"out/soong/dexpreopt_arm64/dex_bootjars_input/baz.jar",
"out/soong/.intermediates/art-bootclasspath-fragment/android_common_apex10000/art-bootclasspath-fragment/boot.prof",
"out/soong/.intermediates/default/java/dex_bootjars/android_common/boot/boot.prof",
+ "out/soong/dexpreopt/uffd_gc_flag.txt",
}
expectedOutputs := []string{
@@ -201,6 +202,7 @@
"out/soong/dexpreopt_arm64/dex_bootjars_input/baz.jar",
"out/soong/.intermediates/prebuilt_com.android.art.deapexer/android_common/deapexer/etc/boot-image.prof",
"out/soong/.intermediates/default/java/dex_bootjars/android_common/boot/boot.prof",
+ "out/soong/dexpreopt/uffd_gc_flag.txt",
}
expectedOutputs := []string{
diff --git a/dexpreopt/config.go b/dexpreopt/config.go
index 6163952..fe6317c 100644
--- a/dexpreopt/config.go
+++ b/dexpreopt/config.go
@@ -98,7 +98,9 @@
// measure, as it masks real errors and affects performance.
RelaxUsesLibraryCheck bool
- EnableUffdGc bool // preopt with the assumption that userfaultfd GC will be used on device.
+ // "true" to force preopt with CMC GC (a.k.a., UFFD GC); "false" to force preopt with CC GC;
+ // "default" to determine the GC type based on the kernel version file.
+ EnableUffdGc string
}
var allPlatformSystemServerJarsKey = android.NewOnceKey("allPlatformSystemServerJars")
@@ -154,6 +156,7 @@
Zip2zip android.Path
ManifestCheck android.Path
ConstructContext android.Path
+ UffdGcFlag android.WritablePath
}
type ModuleConfig struct {
@@ -537,6 +540,7 @@
Zip2zip: ctx.Config().HostToolPath(ctx, "zip2zip"),
ManifestCheck: ctx.Config().HostToolPath(ctx, "manifest_check"),
ConstructContext: ctx.Config().HostToolPath(ctx, "construct_context"),
+ UffdGcFlag: getUffdGcFlagPath(ctx),
}
}
@@ -588,6 +592,7 @@
Zip2zip string
ManifestCheck string
ConstructContext string
+ UffdGcFlag string
}
// ParseGlobalSoongConfig parses the given data assumed to be read from the
@@ -609,6 +614,7 @@
Zip2zip: constructPath(ctx, jc.Zip2zip),
ManifestCheck: constructPath(ctx, jc.ManifestCheck),
ConstructContext: constructPath(ctx, jc.ConstructContext),
+ UffdGcFlag: constructWritablePath(ctx, jc.UffdGcFlag),
}
return config, nil
@@ -633,12 +639,15 @@
}
func (s *globalSoongConfigSingleton) GenerateBuildActions(ctx android.SingletonContext) {
- checkBootJarsConfigConsistency(ctx, GetGlobalConfig(ctx), ctx.Config())
+ global := GetGlobalConfig(ctx)
+ checkBootJarsConfigConsistency(ctx, global, ctx.Config())
- if GetGlobalConfig(ctx).DisablePreopt {
+ if global.DisablePreopt {
return
}
+ buildUffdGcFlag(ctx, global)
+
config := GetCachedGlobalSoongConfig(ctx)
if config == nil {
// No module has enabled dexpreopting, so we assume there will be no calls
@@ -654,6 +663,7 @@
Zip2zip: config.Zip2zip.String(),
ManifestCheck: config.ManifestCheck.String(),
ConstructContext: config.ConstructContext.String(),
+ UffdGcFlag: config.UffdGcFlag.String(),
}
data, err := json.Marshal(jc)
@@ -684,9 +694,32 @@
config.Zip2zip.String(),
config.ManifestCheck.String(),
config.ConstructContext.String(),
+ config.UffdGcFlag.String(),
}, " "))
}
+func buildUffdGcFlag(ctx android.BuilderContext, global *GlobalConfig) {
+ uffdGcFlag := getUffdGcFlagPath(ctx)
+
+ if global.EnableUffdGc == "true" {
+ android.WriteFileRuleVerbatim(ctx, uffdGcFlag, "--runtime-arg -Xgc:CMC")
+ } else if global.EnableUffdGc == "false" {
+ android.WriteFileRuleVerbatim(ctx, uffdGcFlag, "")
+ } else if global.EnableUffdGc == "default" {
+ // Generated by `build/make/core/Makefile`.
+ kernelVersionFile := android.PathForOutput(ctx, "dexpreopt/kernel_version_for_uffd_gc.txt")
+ // Determine the UFFD GC flag by the kernel version file.
+ rule := android.NewRuleBuilder(pctx, ctx)
+ rule.Command().
+ Tool(ctx.Config().HostToolPath(ctx, "construct_uffd_gc_flag")).
+ Input(kernelVersionFile).
+ Output(uffdGcFlag)
+ rule.Restat().Build("dexpreopt_uffd_gc_flag", "dexpreopt_uffd_gc_flag")
+ } else {
+ panic(fmt.Sprintf("Unknown value of PRODUCT_ENABLE_UFFD_GC: %s", global.EnableUffdGc))
+ }
+}
+
func GlobalConfigForTests(ctx android.PathContext) *GlobalConfig {
return &GlobalConfig{
DisablePreopt: false,
@@ -731,7 +764,7 @@
}
}
-func globalSoongConfigForTests() *GlobalSoongConfig {
+func globalSoongConfigForTests(ctx android.BuilderContext) *GlobalSoongConfig {
return &GlobalSoongConfig{
Profman: android.PathForTesting("profman"),
Dex2oat: android.PathForTesting("dex2oat"),
@@ -740,5 +773,19 @@
Zip2zip: android.PathForTesting("zip2zip"),
ManifestCheck: android.PathForTesting("manifest_check"),
ConstructContext: android.PathForTesting("construct_context"),
+ UffdGcFlag: android.PathForOutput(ctx, "dexpreopt_test", "uffd_gc_flag.txt"),
}
}
+
+func GetDexpreoptDirName(ctx android.PathContext) string {
+ prefix := "dexpreopt_"
+ targets := ctx.Config().Targets[android.Android]
+ if len(targets) > 0 {
+ return prefix + targets[0].Arch.ArchType.String()
+ }
+ return prefix + "unknown_target"
+}
+
+func getUffdGcFlagPath(ctx android.PathContext) android.WritablePath {
+ return android.PathForOutput(ctx, "dexpreopt/uffd_gc_flag.txt")
+}
diff --git a/dexpreopt/dexpreopt.go b/dexpreopt/dexpreopt.go
index 94707ba..04bc61d 100644
--- a/dexpreopt/dexpreopt.go
+++ b/dexpreopt/dexpreopt.go
@@ -390,7 +390,8 @@
Flag("--generate-build-id").
Flag("--abort-on-hard-verifier-error").
Flag("--force-determinism").
- FlagWithArg("--no-inline-from=", "core-oj.jar")
+ FlagWithArg("--no-inline-from=", "core-oj.jar").
+ Text("$(cat").Input(globalSoong.UffdGcFlag).Text(")")
var preoptFlags []string
if len(module.PreoptFlags) > 0 {
@@ -506,10 +507,6 @@
cmd.FlagWithInput("--profile-file=", profile)
}
- if global.EnableUffdGc {
- cmd.Flag("--runtime-arg").Flag("-Xgc:CMC")
- }
-
rule.Install(odexPath, odexInstallPath)
rule.Install(vdexPath, vdexInstallPath)
}
diff --git a/dexpreopt/dexpreopt_test.go b/dexpreopt/dexpreopt_test.go
index 230fbb4..7071f3e 100644
--- a/dexpreopt/dexpreopt_test.go
+++ b/dexpreopt/dexpreopt_test.go
@@ -96,7 +96,7 @@
func TestDexPreopt(t *testing.T) {
config := android.TestConfig("out", nil, "", nil)
ctx := android.BuilderContextForTesting(config)
- globalSoong := globalSoongConfigForTests()
+ globalSoong := globalSoongConfigForTests(ctx)
global := GlobalConfigForTests(ctx)
module := testSystemModuleConfig(ctx, "test")
productPackages := android.PathForTesting("product_packages.txt")
@@ -114,12 +114,15 @@
if rule.Installs().String() != wantInstalls.String() {
t.Errorf("\nwant installs:\n %v\ngot:\n %v", wantInstalls, rule.Installs())
}
+
+ android.AssertStringListContains(t, "", rule.Inputs().RelativeToTop().Strings(),
+ "out/soong/dexpreopt_test/uffd_gc_flag.txt")
}
func TestDexPreoptSystemOther(t *testing.T) {
config := android.TestConfig("out", nil, "", nil)
ctx := android.BuilderContextForTesting(config)
- globalSoong := globalSoongConfigForTests()
+ globalSoong := globalSoongConfigForTests(ctx)
global := GlobalConfigForTests(ctx)
systemModule := testSystemModuleConfig(ctx, "Stest")
systemProductModule := testSystemProductModuleConfig(ctx, "SPtest")
@@ -180,7 +183,7 @@
func TestDexPreoptApexSystemServerJars(t *testing.T) {
config := android.TestConfig("out", nil, "", nil)
ctx := android.BuilderContextForTesting(config)
- globalSoong := globalSoongConfigForTests()
+ globalSoong := globalSoongConfigForTests(ctx)
global := GlobalConfigForTests(ctx)
module := testApexModuleConfig(ctx, "service-A", "com.android.apex1")
productPackages := android.PathForTesting("product_packages.txt")
@@ -204,7 +207,7 @@
func TestDexPreoptStandaloneSystemServerJars(t *testing.T) {
config := android.TestConfig("out", nil, "", nil)
ctx := android.BuilderContextForTesting(config)
- globalSoong := globalSoongConfigForTests()
+ globalSoong := globalSoongConfigForTests(ctx)
global := GlobalConfigForTests(ctx)
module := testPlatformSystemServerModuleConfig(ctx, "service-A")
productPackages := android.PathForTesting("product_packages.txt")
@@ -228,7 +231,7 @@
func TestDexPreoptSystemExtSystemServerJars(t *testing.T) {
config := android.TestConfig("out", nil, "", nil)
ctx := android.BuilderContextForTesting(config)
- globalSoong := globalSoongConfigForTests()
+ globalSoong := globalSoongConfigForTests(ctx)
global := GlobalConfigForTests(ctx)
module := testSystemExtSystemServerModuleConfig(ctx, "service-A")
productPackages := android.PathForTesting("product_packages.txt")
@@ -252,7 +255,7 @@
func TestDexPreoptApexStandaloneSystemServerJars(t *testing.T) {
config := android.TestConfig("out", nil, "", nil)
ctx := android.BuilderContextForTesting(config)
- globalSoong := globalSoongConfigForTests()
+ globalSoong := globalSoongConfigForTests(ctx)
global := GlobalConfigForTests(ctx)
module := testApexModuleConfig(ctx, "service-A", "com.android.apex1")
productPackages := android.PathForTesting("product_packages.txt")
@@ -276,7 +279,7 @@
func TestDexPreoptProfile(t *testing.T) {
config := android.TestConfig("out", nil, "", nil)
ctx := android.BuilderContextForTesting(config)
- globalSoong := globalSoongConfigForTests()
+ globalSoong := globalSoongConfigForTests(ctx)
global := GlobalConfigForTests(ctx)
module := testSystemModuleConfig(ctx, "test")
productPackages := android.PathForTesting("product_packages.txt")
@@ -316,3 +319,55 @@
after := fmt.Sprintf("%v", parsed)
android.AssertStringEquals(t, "The result must be the same as the original after marshalling and unmarshalling it.", before, after)
}
+
+func TestUffdGcFlagForce(t *testing.T) {
+ for _, enableUffdGc := range []string{"true", "false"} {
+ t.Run(enableUffdGc, func(t *testing.T) {
+ preparers := android.GroupFixturePreparers(
+ PrepareForTestWithFakeDex2oatd,
+ PrepareForTestWithDexpreoptConfig,
+ FixtureSetEnableUffdGc(enableUffdGc),
+ )
+
+ result := preparers.RunTest(t)
+ ctx := result.TestContext
+
+ ctx.SingletonForTests("dexpreopt-soong-config").Output("out/soong/dexpreopt/uffd_gc_flag.txt")
+ })
+ }
+}
+
+func TestUffdGcFlagDefault(t *testing.T) {
+ preparers := android.GroupFixturePreparers(
+ PrepareForTestWithFakeDex2oatd,
+ PrepareForTestWithDexpreoptConfig,
+ FixtureSetEnableUffdGc("default"),
+ )
+
+ result := preparers.RunTest(t)
+ ctx := result.TestContext
+ config := ctx.Config()
+
+ rule := ctx.SingletonForTests("dexpreopt-soong-config").Rule("dexpreopt_uffd_gc_flag")
+
+ android.AssertStringDoesContain(t, "", rule.RuleParams.Command, "construct_uffd_gc_flag")
+ android.AssertStringPathsRelativeToTopEquals(t, "", config, []string{
+ "out/soong/dexpreopt/uffd_gc_flag.txt",
+ }, rule.AllOutputs())
+ android.AssertPathsRelativeToTopEquals(t, "", []string{
+ "out/soong/dexpreopt/kernel_version_for_uffd_gc.txt",
+ }, rule.Implicits)
+}
+
+func TestUffdGcFlagBogus(t *testing.T) {
+ preparers := android.GroupFixturePreparers(
+ PrepareForTestWithFakeDex2oatd,
+ PrepareForTestWithDexpreoptConfig,
+ FixtureSetEnableUffdGc("bogus"),
+ )
+
+ preparers.
+ ExtendWithErrorHandler(android.FixtureExpectsAtLeastOneErrorMatchingPattern(
+ "Unknown value of PRODUCT_ENABLE_UFFD_GC: bogus")).
+ RunTest(t)
+}
diff --git a/dexpreopt/testing.go b/dexpreopt/testing.go
index 147a562..b1fbef5 100644
--- a/dexpreopt/testing.go
+++ b/dexpreopt/testing.go
@@ -88,6 +88,15 @@
FixtureModifyGlobalConfig(func(android.PathContext, *GlobalConfig) {}),
)
+var PrepareForTestWithDexpreoptConfig = android.GroupFixturePreparers(
+ android.PrepareForTestWithAndroidBuildComponents,
+ android.FixtureModifyContext(func(ctx *android.TestContext) {
+ ctx.RegisterParallelSingletonType("dexpreopt-soong-config", func() android.Singleton {
+ return &globalSoongConfigSingleton{}
+ })
+ }),
+)
+
// FixtureModifyGlobalConfig enables dexpreopt (unless modified by the mutator) and modifies the
// configuration.
func FixtureModifyGlobalConfig(configModifier func(ctx android.PathContext, dexpreoptConfig *GlobalConfig)) android.FixturePreparer {
@@ -195,3 +204,10 @@
dexpreoptConfig.DisablePreopt = disable
})
}
+
+// FixtureSetEnableUffdGc sets the EnableUffdGc property in the global config.
+func FixtureSetEnableUffdGc(value string) android.FixturePreparer {
+ return FixtureModifyGlobalConfig(func(_ android.PathContext, dexpreoptConfig *GlobalConfig) {
+ dexpreoptConfig.EnableUffdGc = value
+ })
+}
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index ec8b4c8..01f60d4 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -617,7 +617,8 @@
// GenerateSingletonBuildActions generates build rules for the dexpreopt config for Make.
func (d *dexpreoptBootJars) GenerateSingletonBuildActions(ctx android.SingletonContext) {
- d.dexpreoptConfigForMake = android.PathForOutput(ctx, getDexpreoptDirName(ctx), "dexpreopt.config")
+ d.dexpreoptConfigForMake =
+ android.PathForOutput(ctx, dexpreopt.GetDexpreoptDirName(ctx), "dexpreopt.config")
writeGlobalConfigForMake(ctx, d.dexpreoptConfigForMake)
}
@@ -1066,8 +1067,8 @@
cmd.FlagWithArg("--instruction-set-features=", global.InstructionSetFeatures[arch])
}
- if global.EnableUffdGc && image.target.Os == android.Android {
- cmd.Flag("--runtime-arg").Flag("-Xgc:CMC")
+ if image.target.Os == android.Android {
+ cmd.Text("$(cat").Input(globalSoong.UffdGcFlag).Text(")")
}
if global.BootFlags != "" {
@@ -1235,7 +1236,7 @@
func dumpOatRules(ctx android.ModuleContext, image *bootImageConfig) {
var allPhonies android.Paths
name := image.name
- global := dexpreopt.GetGlobalConfig(ctx)
+ globalSoong := dexpreopt.GetGlobalSoongConfig(ctx)
for _, image := range image.variants {
arch := image.target.Arch.ArchType
suffix := arch.String()
@@ -1247,6 +1248,7 @@
output := android.PathForOutput(ctx, name+"."+suffix+".oatdump.txt")
rule := android.NewRuleBuilder(pctx, ctx)
imageLocationsOnHost, _ := image.imageLocations()
+
cmd := rule.Command().
BuiltTool("oatdump").
FlagWithInputList("--runtime-arg -Xbootclasspath:", image.dexPathsDeps.Paths(), ":").
@@ -1254,8 +1256,8 @@
FlagWithArg("--image=", strings.Join(imageLocationsOnHost, ":")).Implicits(image.imagesDeps.Paths()).
FlagWithOutput("--output=", output).
FlagWithArg("--instruction-set=", arch.String())
- if global.EnableUffdGc && image.target.Os == android.Android {
- cmd.Flag("--runtime-arg").Flag("-Xgc:CMC")
+ if image.target.Os == android.Android {
+ cmd.Text("$(cat").Input(globalSoong.UffdGcFlag).Text(")")
}
rule.Build("dump-oat-"+name+"-"+suffix, "dump oat "+name+" "+arch.String())
diff --git a/java/dexpreopt_config.go b/java/dexpreopt_config.go
index 254b2c1..dc0973c 100644
--- a/java/dexpreopt_config.go
+++ b/java/dexpreopt_config.go
@@ -115,7 +115,7 @@
func genBootImageConfigs(ctx android.PathContext) map[string]*bootImageConfig {
return ctx.Config().Once(bootImageConfigKey, func() interface{} {
targets := dexpreoptTargets(ctx)
- deviceDir := android.PathForOutput(ctx, getDexpreoptDirName(ctx))
+ deviceDir := android.PathForOutput(ctx, dexpreopt.GetDexpreoptDirName(ctx))
configs := genBootImageConfigRaw(ctx)
@@ -234,12 +234,3 @@
func dexpreoptConfigMakevars(ctx android.MakeVarsContext) {
ctx.Strict("DEXPREOPT_BOOT_JARS_MODULES", strings.Join(defaultBootImageConfig(ctx).modules.CopyOfApexJarPairs(), ":"))
}
-
-func getDexpreoptDirName(ctx android.PathContext) string {
- prefix := "dexpreopt_"
- targets := ctx.Config().Targets[android.Android]
- if len(targets) > 0 {
- return prefix + targets[0].Arch.ArchType.String()
- }
- return prefix + "unknown_target"
-}
diff --git a/scripts/Android.bp b/scripts/Android.bp
index 7baaadb..e2fd59f 100644
--- a/scripts/Android.bp
+++ b/scripts/Android.bp
@@ -143,6 +143,39 @@
}
python_library_host {
+ name: "uffd_gc_utils",
+ srcs: [
+ "uffd_gc_utils.py",
+ ],
+ visibility: [
+ "//build/make/tools:__subpackages__",
+ ],
+}
+
+python_test_host {
+ name: "uffd_gc_utils_test",
+ main: "uffd_gc_utils_test.py",
+ srcs: [
+ "uffd_gc_utils_test.py",
+ ],
+ libs: [
+ "uffd_gc_utils",
+ ],
+ test_suites: ["general-tests"],
+}
+
+python_binary_host {
+ name: "construct_uffd_gc_flag",
+ main: "construct_uffd_gc_flag.py",
+ srcs: [
+ "construct_uffd_gc_flag.py",
+ ],
+ libs: [
+ "uffd_gc_utils",
+ ],
+}
+
+python_library_host {
name: "ninja_rsp",
srcs: ["ninja_rsp.py"],
}
diff --git a/scripts/construct_uffd_gc_flag.py b/scripts/construct_uffd_gc_flag.py
new file mode 100644
index 0000000..f437961
--- /dev/null
+++ b/scripts/construct_uffd_gc_flag.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2024 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""A tool for constructing UFFD GC flag."""
+
+import argparse
+import os
+
+from uffd_gc_utils import should_enable_uffd_gc
+
+
+def parse_args():
+ parser = argparse.ArgumentParser()
+ parser.add_argument('kernel_version_file')
+ parser.add_argument('output')
+ return parser.parse_args()
+
+def main():
+ args = parse_args()
+ enable_uffd_gc = should_enable_uffd_gc(args.kernel_version_file)
+ flag = '--runtime-arg -Xgc:CMC' if enable_uffd_gc else ''
+ # Prevent the file's mtime from being changed if the contents don't change.
+ # This avoids unnecessary dexpreopt reruns.
+ if os.path.isfile(args.output):
+ with open(args.output, 'r') as f:
+ if f.read() == flag:
+ return
+ with open(args.output, 'w') as f:
+ f.write(flag)
+
+
+if __name__ == '__main__':
+ main()
diff --git a/scripts/uffd_gc_utils.py b/scripts/uffd_gc_utils.py
new file mode 100644
index 0000000..2d35494
--- /dev/null
+++ b/scripts/uffd_gc_utils.py
@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2024 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""Utils to determine whether to enable UFFD GC."""
+
+import re
+import sys
+
+
+def should_enable_uffd_gc(kernel_version_file):
+ with open(kernel_version_file, 'r') as f:
+ kernel_version = f.read().strip()
+ return should_enable_uffd_gc_impl(kernel_version)
+
+def should_enable_uffd_gc_impl(kernel_version):
+ # See https://source.android.com/docs/core/architecture/kernel/gki-versioning#determine-release
+ p = r"^(?P<w>\d+)[.](?P<x>\d+)[.](?P<y>\d+)(-android(?P<z>\d+)-(?P<k>\d+).*$)?"
+ m = re.match(p, kernel_version)
+ if m is not None:
+ if m.group('z') is not None:
+ android_release = int(m.group('z'))
+ # No need to check w, x, y because all Android 12 kernels have backports.
+ return android_release >= 12
+ else:
+ # Old kernel or non-GKI kernel.
+ version = int(m.group('w'))
+ patch_level = int(m.group('x'))
+ if version < 5:
+ # Old kernel.
+ return False
+ elif (version == 5 and patch_level >= 7) or version >= 6:
+ # New non-GKI kernel. 5.7 supports MREMAP_DONTUNMAP without the need for
+ # backports.
+ return True
+ else:
+ # Non-GKI kernel between 5 and 5.6. It may have backports.
+ raise exit_with_error(kernel_version)
+ elif kernel_version == '<unknown-kernel>':
+ # The kernel information isn't available to the build system, probably
+ # because PRODUCT_OTA_ENFORCE_VINTF_KERNEL_REQUIREMENTS is set to false. We
+ # assume that the kernel supports UFFD GC because it is the case for most of
+ # the products today and it is the future.
+ return True
+ else:
+ # Unrecognizable non-GKI kernel.
+ raise exit_with_error(kernel_version)
+
+def exit_with_error(kernel_version):
+ sys.exit(f"""
+Unable to determine UFFD GC flag for kernel version "{kernel_version}".
+You can fix this by explicitly setting PRODUCT_ENABLE_UFFD_GC to "true" or
+"false" based on the kernel version.
+1. Set PRODUCT_ENABLE_UFFD_GC to "true" if the kernel supports userfaultfd(2)
+ and MREMAP_DONTUNMAP.
+2. Set PRODUCT_ENABLE_UFFD_GC to "false" otherwise.""")
diff --git a/scripts/uffd_gc_utils_test.py b/scripts/uffd_gc_utils_test.py
new file mode 100644
index 0000000..c86ab4b
--- /dev/null
+++ b/scripts/uffd_gc_utils_test.py
@@ -0,0 +1,61 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2024 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""Unit tests for uffd_gc_utils.py."""
+
+import unittest
+
+from uffd_gc_utils import should_enable_uffd_gc_impl
+
+
+class UffdGcUtilsTest(unittest.TestCase):
+ def test_should_enable_uffd_gc_impl(self):
+ # GKI kernels in new format.
+ self.assertTrue(should_enable_uffd_gc_impl(
+ "6.1.25-android14-11-g34fde9ec08a3-ab10675345"))
+ self.assertTrue(should_enable_uffd_gc_impl(
+ "5.4.42-android12-0-something"))
+ self.assertFalse(should_enable_uffd_gc_impl(
+ "5.4.42-android11-0-something"))
+ # GKI kernels in old format.
+ self.assertFalse(should_enable_uffd_gc_impl(
+ "4.19.282-g4b749a433956-ab10893502"))
+ # Non GKI kernels.
+ self.assertTrue(should_enable_uffd_gc_impl(
+ "6.1.25-foo"))
+ self.assertTrue(should_enable_uffd_gc_impl(
+ "6.1.25"))
+ self.assertTrue(should_enable_uffd_gc_impl(
+ "5.10.19-foo"))
+ self.assertTrue(should_enable_uffd_gc_impl(
+ "5.10.19"))
+ with self.assertRaises(SystemExit):
+ should_enable_uffd_gc_impl("5.4.42-foo")
+ with self.assertRaises(SystemExit):
+ should_enable_uffd_gc_impl("5.4.42")
+ self.assertFalse(should_enable_uffd_gc_impl(
+ "4.19.282-foo"))
+ self.assertFalse(should_enable_uffd_gc_impl(
+ "4.19.282"))
+ with self.assertRaises(SystemExit):
+ should_enable_uffd_gc_impl("foo")
+ # No kernel.
+ self.assertTrue(should_enable_uffd_gc_impl(
+ "<unknown-kernel>"))
+
+
+if __name__ == '__main__':
+ unittest.main(verbosity=2)