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Clear invalid JobScheduler data on boot
For unknown reasons, there have been two instances in the wild where Android, at some point, reassigned Custota's app UID. Perhaps something caused Custota's APK to disappear temporarily for one boot? When this happens, the JobScheduler XML file for the old UID gets left behind. While the old job does not show up in `dumpsys jobscheduler`, it still continues to run. This can cause crashes when UpdaterJob is launched with invalid old parameters. This commit works around the problem by deleting JobScheduler XML files with a matching package name, but invalid UID, during boot. Fixes: #116 Signed-off-by: Andrew Gunnerson <accounts+github@chiller3.com>
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‎app/module/post-fs-data.sh

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@@ -55,6 +55,16 @@ find /data/system/package_cache -name "${app_id}-*" -exec ls -ldZ {} \+
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run_cli_apk com.chiller3.custota.standalone.ClearPackageManagerCachesKt
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# On some devices, the UID for the app seems to get reassigned. If this happens,
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# nothing will clear out the old JobScheduler job and it still runs, despite it
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# not showing up in `dumpsys jobscheduler`. This can cause obscure crashes if
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# the old job launches UpdaterJob with unexpected parameters. Work around this
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# by forcibly deleting jobs with a matching package name, but invalid UID.
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header Clear bad JobScheduler data
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run_cli_apk com.chiller3.custota.standalone.ClearBadJobSchedulerDataKt
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# Bind mount the appropriate CA stores so that update_engine will use the
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# regular system CA store.
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‎app/src/main/java/com/chiller3/custota/standalone/ClearBadJobSchedulerData.kt

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/*
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* SPDX-FileCopyrightText: 2025 Andrew Gunnerson
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* SPDX-License-Identifier: GPL-3.0-only
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* Based on BCR code.
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*/
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@file:Suppress("SameParameterValue")
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package com.chiller3.custota.standalone
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import android.annotation.SuppressLint
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import android.util.Log
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import android.util.Xml
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import com.chiller3.custota.BuildConfig
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import org.xmlpull.v1.XmlPullParser
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import java.io.InputStream
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import java.lang.invoke.MethodHandles
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import java.nio.file.Path
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import java.nio.file.Paths
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import kotlin.io.path.ExperimentalPathApi
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import kotlin.io.path.deleteIfExists
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import kotlin.io.path.inputStream
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import kotlin.io.path.isRegularFile
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import kotlin.io.path.walk
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import kotlin.system.exitProcess
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private val TAG = MethodHandles.lookup().lookupClass().simpleName
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private val PACKAGES_FILE = Paths.get("/data/system/packages.xml")
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private val JOB_SCHEDULER_DIR = Paths.get("/data/system/job")
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private var dryRun = false
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private fun delete(path: Path) {
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if (dryRun) {
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Log.i(TAG, "Would have deleted: $path")
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} else {
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Log.i(TAG, "Deleting: $path")
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path.deleteIfExists()
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}
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}
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@SuppressLint("BlockedPrivateApi")
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private fun resolvePullParser(stream: InputStream): XmlPullParser {
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val method = Xml::class.java.getDeclaredMethod("resolvePullParser", InputStream::class.java)
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return method.invoke(null, stream) as XmlPullParser
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}
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private fun parseJobPackage(parser: XmlPullParser): Pair<String, Int>? {
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val tags = mutableListOf<String>()
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while (true) {
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val token = parser.nextToken()
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when (token) {
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XmlPullParser.START_TAG -> {
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tags.add(parser.name)
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if (tags.size == 2 && tags[0] == "job-info" && tags[1] == "job") {
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val name = (0 until parser.attributeCount)
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.find { parser.getAttributeName(it) == "package" }
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?.let { parser.getAttributeValue(it) }
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?: throw IllegalStateException("<job> has no 'package' attribute")
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val userId = (0 until parser.attributeCount)
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.find { parser.getAttributeName(it) == "uid" }
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?.let { parser.getAttributeValue(it) }
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?: throw IllegalStateException("<job> has no 'uid' attribute")
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return name to userId.toInt()
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}
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}
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XmlPullParser.END_TAG -> {
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if (tags.removeLastOrNull() == null) {
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throw IllegalStateException("Tag stack is empty")
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}
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}
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XmlPullParser.END_DOCUMENT -> break
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}
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}
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return null
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}
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@OptIn(ExperimentalPathApi::class)
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private fun clearBadJobSchedulerData(packageName: String, uid: Int?): Boolean {
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var ret = true
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for (path in JOB_SCHEDULER_DIR.walk()) {
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if (!path.isRegularFile()) {
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continue
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}
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val (jobPackageName, jobUid) = try {
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path.inputStream().use { parseJobPackage(resolvePullParser(it)) } ?: continue
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} catch (e: Exception) {
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Log.w(TAG, "Failed to parse $path", e)
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ret = false
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continue
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}
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try {
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if (jobPackageName == packageName && jobUid != uid) {
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delete(path)
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}
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} catch (e: Exception) {
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Log.w(TAG, "Failed to delete $path", e)
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ret = false
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}
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}
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return ret
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}
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private fun parsePackageUid(parser: XmlPullParser, packageName: String): Int? {
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val tags = mutableListOf<String>()
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while (true) {
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val token = parser.nextToken()
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when (token) {
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XmlPullParser.START_TAG -> {
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tags.add(parser.name)
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if (tags.size == 2 && tags[0] == "packages" && tags[1] == "package") {
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val name = (0 until parser.attributeCount)
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.find { parser.getAttributeName(it) == "name" }
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?.let { parser.getAttributeValue(it) }
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?: throw IllegalStateException("<package> has no 'name' attribute")
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if (name == packageName) {
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val userId = (0 until parser.attributeCount)
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.find { parser.getAttributeName(it) == "userId" }
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?.let { parser.getAttributeValue(it) }
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?: throw IllegalStateException("<package> has no 'userId' attribute")
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return userId.toInt()
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}
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}
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}
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XmlPullParser.END_TAG -> {
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if (tags.removeLastOrNull() == null) {
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throw IllegalStateException("Tag stack is empty")
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}
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}
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XmlPullParser.END_DOCUMENT -> break
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}
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}
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return null
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}
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private fun getPackageUid(packageName: String): Int? =
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PACKAGES_FILE.inputStream().use { input ->
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parsePackageUid(resolvePullParser(input), packageName)
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}
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private fun mainInternal() {
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val expectedUid = getPackageUid(BuildConfig.APPLICATION_ID)
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Log.i(TAG, "Expected UID: $expectedUid")
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clearBadJobSchedulerData(BuildConfig.APPLICATION_ID, expectedUid)
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}
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fun main(args: Array<String>) {
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if ("--dry-run" in args) {
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dryRun = true
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}
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try {
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mainInternal()
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} catch (e: Exception) {
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Log.e(TAG, "Failed to clear bad JobScheduler data", e)
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exitProcess(1)
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}
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}

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