7d292228c1
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
$ANDROID_PRODUCT_OUT/product/etc/build.prop
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=default m` for device with
UFFD support, and do the steps above.
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=true m`, and do the steps
above.
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=false m`, and do the steps
above.
Change-Id: I035ad32233e49e2a30ce11f6c7c318a648511ef8
68 lines
2.6 KiB
Python
68 lines
2.6 KiB
Python
#!/usr/bin/env python
|
|
#
|
|
# Copyright (C) 2024 The Android Open Source Project
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
#
|
|
"""Utils to determine whether to enable UFFD GC."""
|
|
|
|
import re
|
|
import sys
|
|
|
|
|
|
def should_enable_uffd_gc(kernel_version_file):
|
|
with open(kernel_version_file, 'r') as f:
|
|
kernel_version = f.read().strip()
|
|
return should_enable_uffd_gc_impl(kernel_version)
|
|
|
|
def should_enable_uffd_gc_impl(kernel_version):
|
|
# See https://source.android.com/docs/core/architecture/kernel/gki-versioning#determine-release
|
|
p = r"^(?P<w>\d+)[.](?P<x>\d+)[.](?P<y>\d+)(-android(?P<z>\d+)-(?P<k>\d+).*$)?"
|
|
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.""")
|