From 9fae52277efe3502cfd15694ad2936cd7d24c53e Mon Sep 17 00:00:00 2001
From: Mygod <contact-git@mygod.be>
Date: Fri, 7 Aug 2020 09:53:08 +0800
Subject: [PATCH] Use /data if possible

---
 .../be/mygod/librootkotlinx/RootServer.kt     | 48 +++++++++++--------
 1 file changed, 29 insertions(+), 19 deletions(-)

diff --git a/mobile/src/main/java/be/mygod/librootkotlinx/RootServer.kt b/mobile/src/main/java/be/mygod/librootkotlinx/RootServer.kt
index b3c58ccb..71a002a0 100644
--- a/mobile/src/main/java/be/mygod/librootkotlinx/RootServer.kt
+++ b/mobile/src/main/java/be/mygod/librootkotlinx/RootServer.kt
@@ -157,28 +157,38 @@ class RootServer @JvmOverloads constructor(private val warnLogger: (String) -> U
         }
 
         val token2 = UUID.randomUUID().toString()
-        val persistence = File(context.codeCacheDir, ".librootkotlinx-uuid")
-        val uuid = context.packageName + '@' + if (persistence.canRead()) persistence.readText() else {
-            UUID.randomUUID().toString().also { persistence.writeText(it) }
+        val uuid by lazy {
+            val persistence = File(context.codeCacheDir, ".librootkotlinx-uuid")
+            context.packageName + '@' + if (persistence.canRead()) persistence.readText() else {
+                UUID.randomUUID().toString().also { persistence.writeText(it) }
+            }
         }
         // to workaround Samsung's stupid kernel patch, we need to relocate outside of /data: https://github.com/Chainfire/librootjava/issues/19
         val (baseDir, relocated) = if (Build.VERSION.SDK_INT < 29) "/dev" to "/dev/app_process_$uuid" else {
-            val apexPath = "/apex/$uuid"
-            writer.writeBytes("[ -d $apexPath ] || " +
-                    "mkdir $apexPath && " +
-                    // we need to mount a new tmpfs to override noexec flag
-                    "mount -t tmpfs -o size=1M tmpfs $apexPath || exit 1\n")
-            // unfortunately native ld.config.txt only recognizes /data,/system,/system_ext as system directories;
-            // to link correctly, we need to add our path to the linker config too
-            val ldConfig = "$apexPath/etc/ld.config.txt"
-            val masterLdConfig = if (Build.VERSION.SDK_INT == 29) {
-                "/system/etc/ld.config.29.txt"
-            } else "/linkerconfig/ld.config.txt"
-            writer.writeBytes("[ -f $ldConfig ] || " +
-                    "mkdir -p $apexPath/etc && " +
-                    "echo dir.system = $apexPath >$ldConfig && " +
-                    "cat $masterLdConfig >>$ldConfig || exit 1\n")
-            "$apexPath/bin" to "$apexPath/bin/app_process"
+            val cachePath = context.codeCacheDir.canonicalPath
+            if (cachePath.startsWith("/data/")) {
+                val relocated = File(context.codeCacheDir, "relocated")
+                relocated.mkdir()
+                check(relocated.isDirectory)
+                relocated.absolutePath to File(relocated, "app_process").absolutePath
+            } else {
+                val apexPath = "/apex/$uuid"
+                writer.writeBytes("[ -d $apexPath ] || " +
+                        "mkdir $apexPath && " +
+                        // we need to mount a new tmpfs to override noexec flag
+                        "mount -t tmpfs -o size=1M tmpfs $apexPath || exit 1\n")
+                // unfortunately native ld.config.txt only recognizes /data,/system,/system_ext as system directories;
+                // to link correctly, we need to add our path to the linker config too
+                val ldConfig = "$apexPath/etc/ld.config.txt"
+                val masterLdConfig = if (Build.VERSION.SDK_INT == 29) {
+                    "/system/etc/ld.config.29.txt"
+                } else "/linkerconfig/ld.config.txt"
+                writer.writeBytes("[ -f $ldConfig ] || " +
+                        "mkdir -p $apexPath/etc && " +
+                        "echo dir.system = $apexPath >$ldConfig && " +
+                        "cat $masterLdConfig >>$ldConfig || exit 1\n")
+                "$apexPath/bin" to "$apexPath/bin/app_process"
+            }
         }
         writer.writeBytes("[ -f $relocated ] || " +
                 "mkdir -p $baseDir && " +