[core] Fix getprop (#1435)

core/src/main/java/org/lsposed/lspd/service/ConfigFileManager.java

@@ -6,6 +6,7 @@ import static org.lsposed.lspd.service.ServiceManager.toGlobalNamespace;
 import android.content.res.AssetManager;
 import android.content.res.Resources;
 import android.os.ParcelFileDescriptor;
+import android.os.Process;
 import android.os.SELinux;
 import android.os.SharedMemory;
 import android.system.ErrnoException;
@@ -149,8 +150,8 @@ public class ConfigFileManager {
 
     public static boolean chattr0(Path path) {
         try {
-            var dir = Os.open(path.toAbsolutePath().toString(), OsConstants.O_RDONLY, 0);
+            var dir = Os.open(path.toString(), OsConstants.O_RDONLY, 0);
-            HiddenApiBridge.Os_ioctlInt(dir, HiddenApiBridge.VMRuntime_is64Bit() ? 0x40086602 : 0x40046602, 0);
+            HiddenApiBridge.Os_ioctlInt(dir, Process.is64Bit() ? 0x40086602 : 0x40046602, 0);
             Os.close(dir);
             return true;
         } catch (Throwable e) {
@@ -189,7 +190,7 @@ public class ConfigFileManager {
 
     static File getpropsLogPath() throws IOException {
         createLogDirPath();
-        return logDirPath.resolve("props.log").toFile();
+        return logDirPath.resolve("props.txt").toFile();
     }
 
     static Map<String, ParcelFileDescriptor> getLogs() {

core/src/main/java/org/lsposed/lspd/service/LogcatService.java

@@ -2,20 +2,14 @@ package org.lsposed.lspd.service;
 
 import android.annotation.SuppressLint;
 import android.os.ParcelFileDescriptor;
+import android.os.SELinux;
 import android.os.SystemProperties;
 import android.system.Os;
 import android.util.Log;
 
-import org.lsposed.lspd.BuildConfig;
-
-import java.io.BufferedReader;
-import java.io.BufferedWriter;
 import java.io.File;
 import java.io.FileDescriptor;
-import java.io.FileOutputStream;
-import java.io.FileWriter;
 import java.io.IOException;
-import java.io.InputStreamReader;
 import java.nio.file.Files;
 import java.nio.file.LinkOption;
 import java.nio.file.Path;
@@ -36,6 +30,29 @@ public class LogcatService implements Runnable {
         String libraryPath = System.getProperty("lsp.library.path");
         System.load(libraryPath + "/" + System.mapLibraryName("daemon"));
         ConfigFileManager.moveLogDir();
+
+        // Meizu devices set this prop and prevent debug logs from being recorded
+        if (SystemProperties.getInt("persist.sys.log_reject_level", 0) > 0) {
+            SystemProperties.set("persist.sys.log_reject_level", "0");
+        }
+
+        getprop();
+    }
+
+    private static void getprop() {
+        // multithreaded process can not change their context type,
+        // start a new process to set restricted context to filter privacy props
+        var cmd = "echo -n u:r:untrusted_app:s0 > /proc/thread-self/attr/current; getprop";
+        try {
+            SELinux.setFSCreateContext("u:object_r:app_data_file:s0");
+            new ProcessBuilder("sh", "-c", cmd)
+                    .redirectOutput(ConfigFileManager.getpropsLogPath())
+                    .start();
+        } catch (IOException e) {
+            Log.e(TAG, "getprop: ", e);
+        } finally {
+            SELinux.setFSCreateContext(null);
+        }
     }
 
     private native void runLogcat();
@@ -43,10 +60,6 @@ public class LogcatService implements Runnable {
     @Override
     public void run() {
         Log.i(TAG, "start running");
-        // Meizu devices set this prop and prevent debug logs from being recorded
-        if (BuildConfig.DEBUG && SystemProperties.getInt("persist.sys.log_reject_level", 0) > 0) {
-            SystemProperties.set("persist.sys.log_reject_level", "0");
-        }
         runLogcat();
         Log.i(TAG, "stopped");
     }
@@ -80,6 +93,7 @@ public class LogcatService implements Runnable {
         if (fd == -1) return;
         try {
             var jfd = new FileDescriptor();
+            //noinspection JavaReflectionMemberAccess DiscouragedPrivateApi
             jfd.getClass().getDeclaredMethod("setInt$", int.class).invoke(jfd, fd);
             var stat = Os.fstat(jfd);
             if (stat.st_nlink == 0) {
@@ -112,42 +126,6 @@ public class LogcatService implements Runnable {
             start();
         });
         thread.start();
-        getprop();
-    }
-
-    private void getprop() {
-        try {
-            var sb = new StringBuilder();
-            var t = new Thread(() -> {
-                try (var magiskPathReader = new BufferedReader(new InputStreamReader(new ProcessBuilder("magisk", "--path").start().getInputStream()))) {
-                    var magiskPath = magiskPathReader.readLine();
-                    var sh = magiskPath + "/.magisk/busybox/sh";
-                    var pid = Os.getpid();
-                    var tid = Os.gettid();
-                    try (var exec = new FileOutputStream("/proc/" + pid + "/task/" + tid + "/attr/exec")) {
-                        var untrusted = "u:r:untrusted_app:s0";
-                        exec.write(untrusted.getBytes());
-                    }
-                    try (var rd = new BufferedReader(new InputStreamReader(new ProcessBuilder(sh, "-c", "getprop").start().getInputStream()))) {
-                        String line;
-                        while ((line = rd.readLine()) != null) {
-                            sb.append(line);
-                            sb.append(System.lineSeparator());
-                        }
-                    }
-                } catch (IOException e) {
-                    Log.e(TAG, "GetProp: ", e);
-                }
-            });
-            t.start();
-            t.join();
-            var propsLogPath = ConfigFileManager.getpropsLogPath();
-            try (var writer = new BufferedWriter(new FileWriter(propsLogPath))) {
-                writer.append(sb);
-            }
-        } catch (IOException | InterruptedException | NullPointerException e) {
-            Log.e(TAG, "GetProp: ", e);
-        }
     }
 
     public void startVerbose() {
@@ -166,7 +144,7 @@ public class LogcatService implements Runnable {
         }
     }
 
-    static private Path fdToPath(int fd) {
+    private static Path fdToPath(int fd) {
         if (fd == -1) return null;
         else return Paths.get("/proc/self/fd", String.valueOf(fd));
     }

hiddenapi-bridge/src/main/java/hidden/HiddenApiBridge.java

@@ -109,8 +109,4 @@ public class HiddenApiBridge {
             return Os.ioctlInt(fd, cmd);
         }
     }
-
-    public static boolean VMRuntime_is64Bit() {
-        return VMRuntime.getRuntime().is64Bit();
-    }
 }

hiddenapi-stubs/src/main/java/android/os/SELinux.java

@@ -8,4 +8,8 @@ public class SELinux {
     public static boolean setFileContext(String path, String context) {
         throw new UnsupportedOperationException("Stub");
     }
+
+    public static boolean setFSCreateContext(String context){
+        throw new UnsupportedOperationException("Stub");
+    }
 }

hiddenapi-stubs/src/main/java/dalvik/system/VMRuntime.java

@@ -6,7 +6,8 @@ public class VMRuntime {
         throw new RuntimeException("Stub!");
     }
 
+    // Use `Process.is64Bit()` instead
     public native boolean is64Bit();
-    
+
     public native String vmInstructionSet();
 }