From 3a2a2a4ffa86627ac70f351a75808d20499cc832 Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Tue, 13 Nov 2018 02:07:02 -0500
Subject: [PATCH] Micro optimizations

---
 native/jni/daemon/bootstages.cpp       | 14 +++++++-------
 native/jni/daemon/daemon.cpp           | 14 ++++++++++++++
 native/jni/include/daemon.h            |  1 +
 native/jni/magiskhide/proc_monitor.cpp |  8 ++++----
 native/jni/utils/include/utils.h       |  1 -
 native/jni/utils/misc.cpp              | 14 --------------
 6 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/native/jni/daemon/bootstages.cpp b/native/jni/daemon/bootstages.cpp
index f5b96072b..111b5700a 100644
--- a/native/jni/daemon/bootstages.cpp
+++ b/native/jni/daemon/bootstages.cpp
@@ -506,21 +506,21 @@ static bool magisk_env() {
 				strcmp(entry->d_name, ".core") == 0 ||
 				strcmp(entry->d_name, "lost+found") == 0)
 				continue;
-			snprintf(buf, PATH_MAX, "%s/%s/remove", MOUNTPOINT, entry->d_name);
-			if (access(buf, F_OK) == 0) {
-				snprintf(buf, PATH_MAX, "%s/%s", MOUNTPOINT, entry->d_name);
+			snprintf(buf, PATH_MAX, "%s/%s", MOUNTPOINT, entry->d_name);
+			chdir(buf);
+			if (access("remove", F_OK) == 0) {
+				chdir("..");
 				rm_rf(buf);
 				continue;
 			}
-			snprintf(buf, PATH_MAX, "%s/%s/update", MOUNTPOINT, entry->d_name);
-			unlink(buf);
-			snprintf(buf, PATH_MAX, "%s/%s/disable", MOUNTPOINT, entry->d_name);
-			if (access(buf, F_OK) == 0)
+			unlink("update");
+			if (access("disable", F_OK) == 0)
 				continue;
 			module_list.push_back(entry->d_name);
 		}
 	}
 	closedir(dir);
+	chdir("/");
 
 	return trim_img(MAINIMG, MOUNTPOINT, magiskloop) == 0;
 }
diff --git a/native/jni/daemon/daemon.cpp b/native/jni/daemon/daemon.cpp
index 3f72be6bd..1712c5d57 100644
--- a/native/jni/daemon/daemon.cpp
+++ b/native/jni/daemon/daemon.cpp
@@ -132,6 +132,20 @@ static void main_daemon() {
 	}
 }
 
+int switch_mnt_ns(int pid) {
+	char mnt[32];
+	snprintf(mnt, sizeof(mnt), "/proc/%d/ns/mnt", pid);
+	if(access(mnt, R_OK) == -1) return 1; // Maybe process died..
+
+	int fd, ret;
+	fd = xopen(mnt, O_RDONLY);
+	if (fd < 0) return 1;
+	// Switch to its namespace
+	ret = xsetns(fd, 0);
+	close(fd);
+	return ret;
+}
+
 int connect_daemon() {
 	struct sockaddr_un sun;
 	socklen_t len = setup_sockaddr(&sun, MAIN_SOCKET);
diff --git a/native/jni/include/daemon.h b/native/jni/include/daemon.h
index 15f377c5d..44fc6b2e0 100644
--- a/native/jni/include/daemon.h
+++ b/native/jni/include/daemon.h
@@ -37,6 +37,7 @@ enum {
 // daemon.c
 
 int connect_daemon();
+int switch_mnt_ns(int pid);
 
 // log_monitor.c
 
diff --git a/native/jni/magiskhide/proc_monitor.cpp b/native/jni/magiskhide/proc_monitor.cpp
index c38e0ff60..10179b3d2 100644
--- a/native/jni/magiskhide/proc_monitor.cpp
+++ b/native/jni/magiskhide/proc_monitor.cpp
@@ -72,9 +72,10 @@ static void hide_daemon(int pid) {
 	if (switch_mnt_ns(pid))
 		goto exit;
 
-	snprintf(buffer, sizeof(buffer), "/proc/%d/mounts", pid);
-	file_to_vector(buffer, mounts);
+	snprintf(buffer, sizeof(buffer), "/proc/%d", pid);
+	chdir(buffer);
 
+	file_to_vector("mounts", mounts);
 	// Unmount dummy skeletons and /sbin links
 	for (auto &s : mounts) {
 		if (s.contains("tmpfs /system/") || s.contains("tmpfs /vendor/") || s.contains("tmpfs /sbin")) {
@@ -85,8 +86,7 @@ static void hide_daemon(int pid) {
 	mounts.clear();
 
 	// Re-read mount infos
-	snprintf(buffer, sizeof(buffer), "/proc/%d/mounts", pid);
-	file_to_vector(buffer, mounts);
+	file_to_vector("mounts", mounts);
 
 	// Unmount everything under /system, /vendor, and loop mounts
 	for (auto &s : mounts) {
diff --git a/native/jni/utils/include/utils.h b/native/jni/utils/include/utils.h
index a91480f5e..6f71bef76 100644
--- a/native/jni/utils/include/utils.h
+++ b/native/jni/utils/include/utils.h
@@ -94,7 +94,6 @@ int is_num(const char *s);
 int exec_array(int err, int *fd, void (*cb)(void), const char *argv[]);
 int exec_command(int err, int *fd, void (*cb)(void), const char *argv0, ...);
 int exec_command_sync(const char *argv0, ...);
-int switch_mnt_ns(int pid);
 int fork_dont_care();
 void gen_rand_str(char *buf, int len);
 int strend(const char *s1, const char *s2);
diff --git a/native/jni/utils/misc.cpp b/native/jni/utils/misc.cpp
index d7b145ed0..e1a2faec2 100644
--- a/native/jni/utils/misc.cpp
+++ b/native/jni/utils/misc.cpp
@@ -67,20 +67,6 @@ ssize_t fdgets(char *buf, const size_t size, int fd) {
 	return len;
 }
 
-int switch_mnt_ns(int pid) {
-	char mnt[32];
-	snprintf(mnt, sizeof(mnt), "/proc/%d/ns/mnt", pid);
-	if(access(mnt, R_OK) == -1) return 1; // Maybe process died..
-
-	int fd, ret;
-	fd = xopen(mnt, O_RDONLY);
-	if (fd < 0) return 1;
-	// Switch to its namespace
-	ret = xsetns(fd, 0);
-	close(fd);
-	return ret;
-}
-
 int fork_dont_care() {
 	int pid = xfork();
 	if (pid) {