From d959c35723968d660d555529dd46f50fec8d1158 Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Sat, 18 Apr 2020 18:50:25 -0700
Subject: [PATCH] Make cleaner mount info

---
 native/jni/core/module.cpp  |  2 +-
 native/jni/init/init.hpp    |  1 -
 native/jni/init/mount.cpp   |  6 ++++--
 native/jni/init/rootdir.cpp | 20 ++++++++++++--------
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/native/jni/core/module.cpp b/native/jni/core/module.cpp
index 7b7cbff1b..c5a3c3659 100644
--- a/native/jni/core/module.cpp
+++ b/native/jni/core/module.cpp
@@ -165,7 +165,7 @@ public:
 	template<class T, class ...Args>
 	T *emplace_or_get(string_view name, Args &...args) {
 		return iter_to_node<T>(insert(children.find(name), type_id<T>(),
-				[&](auto _) { return new T(std::forward<Args>(args)...); }, true));
+		        [&](auto _) { return new T(std::forward<Args>(args)...); }, true));
 	}
 
 	// Return upgraded node or null if rejected
diff --git a/native/jni/init/init.hpp b/native/jni/init/init.hpp
index 23b6382df..8a749755b 100644
--- a/native/jni/init/init.hpp
+++ b/native/jni/init/init.hpp
@@ -69,7 +69,6 @@ class SARBase : public MagiskInit {
 protected:
 	raw_data config;
 	std::vector<raw_file> overlays;
-	std::string tmp_dir;
 
 	void backup_files();
 	void patch_rootdir();
diff --git a/native/jni/init/mount.cpp b/native/jni/init/mount.cpp
index 73887e00d..138f7430e 100644
--- a/native/jni/init/mount.cpp
+++ b/native/jni/init/mount.cpp
@@ -153,11 +153,13 @@ static void switch_root(const string &path) {
 static void mount_persist(const char *dev_base, const char *mnt_base) {
 	string mnt_point = mnt_base + "/persist"s;
 	strcpy(partname, "persist");
-	sprintf(block_dev, "%s/persist", dev_base);
+	xrealpath(dev_base, block_dev);
+	char *s = block_dev + strlen(block_dev);
+	strcpy(s, "/persist");
 	if (setup_block(false) < 0) {
 		// Fallback to cache
 		strcpy(partname, "cache");
-		sprintf(block_dev, "%s/cache", dev_base);
+		strcpy(s, "/cache");
 		if (setup_block(false) < 0) {
 			// Try NVIDIA's BS
 			strcpy(partname, "CAC");
diff --git a/native/jni/init/rootdir.cpp b/native/jni/init/rootdir.cpp
index 628681595..998a7ebb6 100644
--- a/native/jni/init/rootdir.cpp
+++ b/native/jni/init/rootdir.cpp
@@ -222,24 +222,28 @@ static void magic_mount(const string &sdir, const string &ddir = "") {
 #define LIBSELINUX  "/system/" LIBNAME "/libselinux.so"
 
 void SARBase::patch_rootdir() {
+	char tmp_dir[128];
+
 	// TODO: dynamic paths
-	tmp_dir = "/sbin";
+	char *p = tmp_dir + sprintf(tmp_dir, "%s", "/sbin");
 
-	setup_tmp(tmp_dir.data(), self, config);
-	persist_dir = tmp_dir +  "/" MIRRDIR "/persist";
+	setup_tmp(tmp_dir, self, config);
+	persist_dir = string(tmp_dir) +  "/" MIRRDIR "/persist";
 
-	chdir(tmp_dir.data());
+	chdir(tmp_dir);
 
 	// Mount system_root mirror
 	struct stat st;
 	xstat("/", &st);
 	xmkdir(ROOTMIR, 0755);
 	mknod(ROOTBLK, S_IFBLK | 0600, st.st_dev);
-	if (xmount(ROOTBLK, ROOTMIR, "ext4", MS_RDONLY, nullptr))
-		xmount(ROOTBLK, ROOTMIR, "erofs", MS_RDONLY, nullptr);
+	strcpy(p, "/" ROOTBLK);
+	if (xmount(tmp_dir, ROOTMIR, "ext4", MS_RDONLY, nullptr))
+		xmount(tmp_dir, ROOTMIR, "erofs", MS_RDONLY, nullptr);
+	*p = '\0';
 
 	// Recreate original sbin structure if necessary
-	if (tmp_dir == "/sbin")
+	if (tmp_dir == "/sbin"sv)
 		recreate_sbin(ROOTMIR "/sbin", true);
 
 	// Patch init
@@ -303,7 +307,7 @@ void SARBase::patch_rootdir() {
 	if (connect(sockfd, (struct sockaddr*) &sun, setup_sockaddr(&sun, INIT_SOCKET)) == 0) {
 		LOGD("ACK init tracer to write backup files\n");
 		// Let tracer know where tmp_dir is
-		write_string(sockfd, tmp_dir.data());
+		write_string(sockfd, tmp_dir);
 		// Wait for tracer to finish copying files
 		int ack;
 		read(sockfd, &ack, sizeof(ack));