Add new util function

native/jni/core/bootstages.cpp

@@ -307,13 +307,13 @@ static int bind_mount(const char *from, const char *to, bool log) {
 
 #define MIRRMNT(part)   MIRRDIR "/" #part
 #define PARTBLK(part)   BLOCKDIR "/" #part
+#define DIR_IS(part)    (me->mnt_dir == "/" #part ""sv)
 
 #define mount_mirror(part, flag) { \
-	sscanf(line.data(), "%s %*s %s", buf, buf2); \
-	xstat(buf, &st); \
+	xstat(me->mnt_fsname, &st); \
 	mknod(PARTBLK(part), (st.st_mode & S_IFMT) | 0600, st.st_rdev); \
 	xmkdir(MIRRMNT(part), 0755); \
-	xmount(PARTBLK(part), MIRRMNT(part), buf2, flag, nullptr); \
+	xmount(PARTBLK(part), MIRRMNT(part), me->mnt_type, flag, nullptr); \
 	VLOGI("mount", PARTBLK(part), MIRRMNT(part)); \
 }
 
@@ -364,21 +364,19 @@ static bool magisk_env() {
 	LOGI("* Mounting mirrors");
 	bool system_as_root = false;
 	struct stat st;
-	file_readline("/proc/mounts", [&](string_view line) -> bool {
-		if (str_contains(line, " /system_root ")) {
+	parse_mnt("/proc/mounts", [&](mntent *me) {
+		if (DIR_IS(system_root)) {
 			mount_mirror(system_root, MS_RDONLY);
 			xsymlink(MIRRMNT(system_root) "/system", MIRRMNT(system));
 			VLOGI("link", MIRRMNT(system_root) "/system", MIRRMNT(system));
 			system_as_root = true;
-		} else if (!system_as_root && str_contains(line, " /system ")) {
+		} else if (!system_as_root && DIR_IS(system)) {
 			mount_mirror(system, MS_RDONLY);
-		} else if (str_contains(line, " /vendor ")) {
+		} else if (DIR_IS(vendor)) {
 			mount_mirror(vendor, MS_RDONLY);
-		} else if (str_contains(line, " /data ") && !str_contains(line, "tmpfs")) {
+		} else if (DIR_IS(data) && me->mnt_type != "tmpfs"sv) {
 			mount_mirror(data, 0);
-		} else if (SDK_INT >= 24 &&
-		str_contains(line, " /proc ") && !str_contains(line, "hidepid=2")) {
-			// Enforce hidepid
+		} else if (SDK_INT >= 24 && DIR_IS(proc) && !strstr(me->mnt_opts, "hidepid=2")) {
 			xmount(nullptr, "/proc", nullptr, MS_REMOUNT, "hidepid=2,gid=3009");
 		}
 		return true;

native/jni/magiskhide/hide_policy.cpp

@@ -44,6 +44,9 @@ void hide_daemon(int pid) {
 	hide_unmount(pid);
 }
 
+#define TMPFS_MNT(dir) (mentry->mnt_type == "tmpfs"sv && \
+strncmp(mentry->mnt_dir, "/" #dir, sizeof("/" #dir) - 1) == 0)
+
 void hide_unmount(int pid) {
 	if (switch_mnt_ns(pid))
 		return;
@@ -60,7 +63,7 @@ void hide_unmount(int pid) {
 		chmod(SELINUX_POLICY, 0440);
 	}
 
-	getprop([](const char *name, auto, auto) -> void {
+	getprop([](const char *name, auto, auto) {
 		if (strstr(name, "magisk"))
 			deleteprop(name);
 	}, nullptr, false);
@@ -68,14 +71,9 @@ void hide_unmount(int pid) {
 	vector<string> targets;
 
 	// Unmount dummy skeletons and /sbin links
-	file_readline("/proc/self/mounts", [&](string_view s) -> bool {
-		if (str_contains(s, "tmpfs /system/") || str_contains(s, "tmpfs /vendor/") ||
-			str_contains(s, "tmpfs /sbin")) {
-			char *path = (char *) s.data();
-			// Skip first token
-			strtok_r(nullptr, " ", &path);
-			targets.emplace_back(strtok_r(nullptr, " ", &path));
-		}
+	parse_mnt("/proc/self/mounts", [&](mntent *mentry) {
+		if (TMPFS_MNT(system) || TMPFS_MNT(vendor) || TMPFS_MNT(sbin))
+			targets.emplace_back(mentry->mnt_dir);
 		return true;
 	});
 
@@ -84,13 +82,9 @@ void hide_unmount(int pid) {
 	targets.clear();
 
 	// Unmount all Magisk created mounts
-	file_readline("/proc/self/mounts", [&](string_view s) -> bool {
-		if (str_contains(s, BLOCKDIR)) {
-			char *path = (char *) s.data();
-			// Skip first token
-			strtok_r(nullptr, " ", &path);
-			targets.emplace_back(strtok_r(nullptr, " ", &path));
-		}
+	parse_mnt("/proc/self/mounts", [&](mntent *mentry) {
+		if (strstr(mentry->mnt_fsname, BLOCKDIR))
+			targets.emplace_back(mentry->mnt_dir);
 		return true;
 	});
 

native/jni/utils/file.cpp

@@ -1,15 +1,15 @@
 /* file.cpp - Contains all files related utilities
  */
 
+#include <sys/sendfile.h>
+#include <sys/mman.h>
+#include <linux/fs.h>
 #include <stdlib.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <string.h>
 #include <libgen.h>
-#include <sys/sendfile.h>
-#include <sys/mman.h>
-#include <linux/fs.h>
 
 #include <magisk.h>
 #include <utils.h>
@@ -396,3 +396,14 @@ void parse_prop_file(const char *file, const function<bool (string_view, string_
 		return fn(line, eql + 1);
 	}, true);
 }
+
+void parse_mnt(const char *file, const function<bool (mntent*)> &fn) {
+	unique_ptr<FILE, decltype(&fclose)> fp(xfopen(file, "rce"), &fclose);
+	if (fp) {
+		mntent *mentry;
+		while ((mentry = getmntent(fp.get())) != nullptr) {
+			if (!fn(mentry))
+				break;
+		}
+	}
+}

native/jni/utils/include/utils.h

@@ -3,13 +3,14 @@
 
 #pragma once
 
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
 #include <stdio.h>
 #include <dirent.h>
 #include <pthread.h>
 #include <poll.h>
-#include <sys/socket.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
+#include <mntent.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -173,6 +174,7 @@ void parse_prop_file(const char *file, const std::function
 void *__mmap(const char *filename, size_t *size, bool rw);
 void frm_rf(int dirfd, std::initializer_list<const char *> excl = std::initializer_list<const char *>());
 void clone_dir(int src, int dest, bool overwrite = true);
+void parse_mnt(const char *file, const std::function<bool (mntent*)> &fn);
 
 template <typename B>
 void mmap_ro(const char *filename, B &buf, size_t &sz) {