1

上周发的一篇文章《android 7.1 apk的systemuid和系统应用Setting相同导致开机找不到库的问题》，然后有个小伙伴找我讨论了，觉得自己的脑洞了打开了很多，所以针对这个问题再次做一次总结，如果大家有好的建议也可以在文末留言。

2

先说一个命令 adb shell dumpsys package p > dumpsys_p ，这个命令可以查看apk的一些状态，包括apk属于32位还是64位，保存成文件后查找里面对应的包名，就可以看到对应应用的信息。

看到primaryCpuAbi=arm64-v8a，说明我们的settings应用是64位的。

3

我们先是分析了出现问题时候的Settings，我们用原来的固件复现问题，在出现问题的时候用上面的命令查看，发现Settings已经变成了32位。

Package [com.android.settings] (27afcae):
userId=1000
sharedUser=SharedUserSetting{a6835fb android.uid.system/1000}
pkg=Package{6d89bbd com.android.settings}
codePath=/system/priv-app/Settings
resourcePath=/system/priv-app/Settings
legacyNativeLibraryDir=/system/priv-app/Settings/lib
primaryCpuAbi=armeabi-v7a

4

上篇文章提到，我们报错是因为没有找到库文件，还有下面的日志引起32位和64位不匹配的原因。

PackageManager: Instruction set mismatch, PackageSetting{1e08467
com.xxxxxx.jjjjj.titket.oceanFlower/1000} requires arm whereas
PackageSetting{51ca86c android.rockchip.update.service/1000} requires
arm64 PackageManager: Instruction set mismatch, PackageSetting{1e08467
com.xxxxxx.jjjjj.titket.oceanFlower/1000} requires arm whereas
PackageSetting{992cb54 android/1000} requires arm64

我们的第一个尝试是，直接去掉原来修改的两个宏，然后在Setings安装位置system/priv-app/xxx/目录下面建立一个lib/arm64文件夹。这样复测20次，没有出现问题。原因是，我们的apk，发现当前安装位置下面有lib文件夹，优先从文件夹里去找库，而且是lib/arm64说明是64位的，让Settings运行在64位模式，我们的apk运行在32位模式。

5

添加前面文章的两个宏之后，在生成固件的apk里面多了一个class.dex，我们尝试把这个class.dex放到原来的Settings里面，然后再压缩把原来的Settings替换掉，这样复测20次，也是没有问题。所以这个class.dex起作用了。

• rm /data/system/packages.xml
• 恢复出厂设置
• 测试20次没有出现问题。

然后再查看Setting的运行模式

userId=1000
sharedUser=SharedUserSetting{842777 android.uid.system/1000}
pkg=Package{7785b91 com.android.settings}
codePath=/system/priv-app/Settings
resourcePath=/system/priv-app/Settings
legacyNativeLibraryDir=/system/priv-app/Settings/lib
primaryCpuAbi=armeabi-v7a
Seting变成了32位，就因为我们加了class.dex的原因。

6

后面大神给我了一个补丁，用来解决这个问题，补丁代码如下，希望对有这方面问题的同学有参考意义

diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 12901ba..6d4e6fa 100755
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -2572,7 +2572,7 @@ public class PackageManagerService extends IPackageManager.Stub {// NOTE: We ignore potential failures here during a system scan (like// the rest of the commands above) because there's precious little we// can do about it. A settings error is reported, though.
-                adjustCpuAbisForSharedUserLPw(setting.packages, null /* scanned package */,
+                adjustCpuAbisForSharedUserLPw(setting.sameProcessPackages, null /* scanned package */,false /* boot complete */);}@@ -7222,12 +7222,18 @@ public class PackageManagerService extends IPackageManager.Stub {}private static String fixProcessName(String defProcessName,
-            String processName, int uid) {
-        if (processName == null) {
-            return defProcessName;
-        }
-        return processName;
-    }
+        String processName,PackageSetting ps) {
+        	String returnName = processName;
+        	if (returnName == null) {
+            	returnName =  defProcessName;
+        	}
+			if (returnName!=null && returnName.equals("system")) {
+				if (ps!=null && ps.sharedUser != null)
+				ps.sharedUser.addSameProcessPackage(ps);
+			}
+        return returnName;
+		}
+	private void verifySignaturesLP(PackageSetting pkgSetting, PackageParser.Package pkg)throws PackageManagerException {
@@ -8508,7 +8514,7 @@ public class PackageManagerService extends IPackageManager.Stub {pkg.applicationInfo.processName = fixProcessName(pkg.applicationInfo.packageName,pkg.applicationInfo.processName,
-                pkg.applicationInfo.uid);
+                pkgSetting);if (pkg != mPlatformPackage) {// Get all of our default paths setup
@@ -8774,7 +8780,7 @@ public class PackageManagerService extends IPackageManager.Stub {for (i=0; i<N; i++) {PackageParser.Provider p = pkg.providers.get(i);p.info.processName = fixProcessName(pkg.applicationInfo.processName,
-                        p.info.processName, pkg.applicationInfo.uid);
+                        p.info.processName,(PackageSetting)pkg.mExtras);mProviders.addProvider(p);p.syncable = p.info.isSyncable;if (p.info.authority != null) {
@@ -8833,7 +8839,7 @@ public class PackageManagerService extends IPackageManager.Stub {for (i=0; i<N; i++) {PackageParser.Service s = pkg.services.get(i);s.info.processName = fixProcessName(pkg.applicationInfo.processName,
-                        s.info.processName, pkg.applicationInfo.uid);
+                        s.info.processName,(PackageSetting)pkg.mExtras);mServices.addService(s);if ((policyFlags&PackageParser.PARSE_CHATTY) != 0) {if (r == null) {
@@ -8853,7 +8859,7 @@ public class PackageManagerService extends IPackageManager.Stub {for (i=0; i<N; i++) {PackageParser.Activity a = pkg.receivers.get(i);a.info.processName = fixProcessName(pkg.applicationInfo.processName,
-                        a.info.processName, pkg.applicationInfo.uid);
+                        a.info.processName,(PackageSetting)pkg.mExtras);mReceivers.addActivity(a, "receiver");if ((policyFlags&PackageParser.PARSE_CHATTY) != 0) {if (r == null) {
@@ -8873,7 +8879,7 @@ public class PackageManagerService extends IPackageManager.Stub {for (i=0; i<N; i++) {PackageParser.Activity a = pkg.activities.get(i);a.info.processName = fixProcessName(pkg.applicationInfo.processName,
-                        a.info.processName, pkg.applicationInfo.uid);
+                        a.info.processName,(PackageSetting)pkg.mExtras);mActivities.addActivity(a, "activity");if ((policyFlags&PackageParser.PARSE_CHATTY) != 0) {if (r == null) {
diff --git a/services/core/java/com/android/server/pm/SharedUserSetting.java b/services/core/java/com/android/server/pm/SharedUserSetting.java
old mode 100644
new mode 100755
index 06e020a..01897fb
--- a/services/core/java/com/android/server/pm/SharedUserSetting.java
+++ b/services/core/java/com/android/server/pm/SharedUserSetting.java
@@ -31,6 +31,7 @@ final class SharedUserSetting extends SettingBase {int uidPrivateFlags;final ArraySet<PackageSetting> packages = new ArraySet<PackageSetting>();
+	final ArraySet<PackageSetting> sameProcessPackages = new ArraySet<PackageSetting>();final PackageSignatures signatures = new PackageSignatures();@@ -66,7 +67,11 @@ final class SharedUserSetting extends SettingBase {}}}
-
+	
+    void addSameProcessPackage(PackageSetting packageSetting) {
+		sameProcessPackages.add(packageSetting);
+    }
+		void addPackage(PackageSetting packageSetting) {if (packages.add(packageSetting)) {setFlags(this.pkgFlags | packageSetting.pkgFlags);

7

参考我之前的文章
https://blog.csdn.net/weiqifa0/article/details/88432165
还有一些尝试方法还没有论证，喜欢研究的同学可以继续跟进
至于为何有同一个uid需要运行位数一致，大神找到了这样的解释

Adjust instruction sets for shared UID apps.

Since shared UID apps are run in the same process,
we'll need to make sure they're compiled for the same
instruction set.

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