From 548d70f30cf60c704f779732b277adc2414a31d0 Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Tue, 1 Mar 2022 20:09:59 -0800
Subject: [PATCH] Mount with original option

Fix #5481, close #5486
---
 native/jni/core/bootstages.cpp | 46 +++++++++++++++++++++-------------
 native/jni/utils/misc.cpp      | 18 ++++++++++---
 native/jni/utils/misc.hpp      |  3 ++-
 3 files changed, 44 insertions(+), 23 deletions(-)

diff --git a/native/jni/core/bootstages.cpp b/native/jni/core/bootstages.cpp
index 32a944915..5e0134ae3 100644
--- a/native/jni/core/bootstages.cpp
+++ b/native/jni/core/bootstages.cpp
@@ -29,21 +29,31 @@ bool zygisk_enabled = false;
 #define SETMIR(b, part) snprintf(b, sizeof(b), "%s/" MIRRDIR "/" #part, MAGISKTMP.data())
 #define SETBLK(b, part) snprintf(b, sizeof(b), "%s/" BLOCKDIR "/" #part, MAGISKTMP.data())
 
-#define do_mount_mirror(part, flag) {\
-    SETMIR(buf1, part); \
-    SETBLK(buf2, part); \
-    unlink(buf2); \
+#define do_mount_mirror(part) {     \
+    SETMIR(buf1, part);             \
+    SETBLK(buf2, part);             \
+    unlink(buf2);                   \
     mknod(buf2, S_IFBLK | 0600, st.st_dev); \
-    xmkdir(buf1, 0755); \
-    xmount(buf2, buf1, me->mnt_type, flag, nullptr); \
-    LOGI("mount: %s\n", buf1); \
+    xmkdir(buf1, 0755);             \
+    int flags = 0;                  \
+    auto opts = split_ro(me->mnt_opts, ",");\
+    for (string_view s : opts) {    \
+        if (s == "ro") {            \
+            flags |= MS_RDONLY;     \
+            break;                  \
+        }                           \
+    }                               \
+    xmount(buf2, buf1, me->mnt_type, flags, nullptr); \
+    LOGI("mount: %s\n", buf1);      \
 }
 
-#define mount_mirror(part, flag)    \
-if (MNT_DIR_IS("/" #part) && !MNT_TYPE_IS("tmpfs") && !MNT_TYPE_IS("overlay") && \
-    lstat(me->mnt_dir, &st) == 0) { \
-    do_mount_mirror(part, flag);    \
-    break;                          \
+#define mount_mirror(part) \
+if (MNT_DIR_IS("/" #part)  \
+    && !MNT_TYPE_IS("tmpfs") \
+    && !MNT_TYPE_IS("overlay") \
+    && lstat(me->mnt_dir, &st) == 0) { \
+    do_mount_mirror(part); \
+    break;                 \
 }
 
 #define link_mirror(part) \
@@ -73,11 +83,11 @@ static void mount_mirrors() {
     parse_mnt("/proc/mounts", [&](mntent *me) {
         struct stat st{};
         do {
-            mount_mirror(system, MS_RDONLY)
-            mount_mirror(vendor, MS_RDONLY)
-            mount_mirror(product, MS_RDONLY)
-            mount_mirror(system_ext, MS_RDONLY)
-            mount_mirror(data, 0)
+            mount_mirror(system)
+            mount_mirror(vendor)
+            mount_mirror(product)
+            mount_mirror(system_ext)
+            mount_mirror(data)
             link_orig(cache)
             link_orig(metadata)
             link_orig(persist)
@@ -96,7 +106,7 @@ static void mount_mirrors() {
         parse_mnt("/proc/mounts", [&](mntent *me) {
             struct stat st;
             if (MNT_DIR_IS("/") && me->mnt_type != "rootfs"sv && stat("/", &st) == 0) {
-                do_mount_mirror(system_root, MS_RDONLY)
+                do_mount_mirror(system_root)
                 return false;
             }
             return true;
diff --git a/native/jni/utils/misc.cpp b/native/jni/utils/misc.cpp
index 3ac095b2f..56b5f8c65 100644
--- a/native/jni/utils/misc.cpp
+++ b/native/jni/utils/misc.cpp
@@ -189,15 +189,25 @@ string &replace_all(string &str, string_view from, string_view to) {
     return str;
 }
 
-vector<string> split(const string& s, const string& delimiters) {
-    vector<string> result;
+template <class T>
+static auto split_impl(T s, T delims) {
+    vector<std::decay_t<T>> result;
     size_t base = 0;
     size_t found;
     while (true) {
-        found = s.find_first_of(delimiters, base);
+        found = s.find_first_of(delims, base);
         result.push_back(s.substr(base, found - base));
-        if (found == string::npos) break;
+        if (found == string::npos)
+            break;
         base = found + 1;
     }
     return result;
 }
+
+vector<string> split(const string &s, const string &delims) {
+    return split_impl<const string&>(s, delims);
+}
+
+vector<string_view> split_ro(string_view s, string_view delims) {
+    return split_impl<string_view>(s, delims);
+}
diff --git a/native/jni/utils/misc.hpp b/native/jni/utils/misc.hpp
index 8a8828dcc..683094a50 100644
--- a/native/jni/utils/misc.hpp
+++ b/native/jni/utils/misc.hpp
@@ -159,7 +159,8 @@ uint32_t binary_gcd(uint32_t u, uint32_t v);
 int switch_mnt_ns(int pid);
 int gen_rand_str(char *buf, int len, bool varlen = true);
 std::string &replace_all(std::string &str, std::string_view from, std::string_view to);
-std::vector<std::string> split(const std::string& s, const std::string& delimiters);
+std::vector<std::string> split(const std::string &s, const std::string &delims);
+std::vector<std::string_view> split_ro(std::string_view, std::string_view delims);
 
 struct exec_t {
     bool err = false;