From a19c7215d2bf5bba14c01d3d8e222647e247e4ce Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Fri, 15 Feb 2019 04:31:39 -0500
Subject: [PATCH] Better nice name

---
 native/jni/core/applets.cpp      |  8 +++-----
 native/jni/core/daemon.cpp       |  2 +-
 native/jni/include/magisk.h      |  1 -
 native/jni/utils/include/utils.h |  2 ++
 native/jni/utils/misc.cpp        | 12 ++++++++++++
 5 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/native/jni/core/applets.cpp b/native/jni/core/applets.cpp
index eed645048..f130a8dab 100644
--- a/native/jni/core/applets.cpp
+++ b/native/jni/core/applets.cpp
@@ -6,17 +6,15 @@
 
 #include <magisk.h>
 #include <selinux.h>
+#include <utils.h>
 
 static int (*applet_main[]) (int, char *[]) =
 		{ magisk_main, su_client_main, resetprop_main, magiskhide_main, nullptr };
 
-char *argv0;
-
 __attribute__((noreturn)) static void call_applets(int argc, char *argv[]) {
 	// Applets
 	for (int i = 0; applet_names[i]; ++i) {
 		if (strcmp(basename(argv[0]), applet_names[i]) == 0) {
-			strcpy(argv0, basename(argv[0]));
 			exit((*applet_main[i])(argc, argv));
 		}
 	}
@@ -26,11 +24,11 @@ __attribute__((noreturn)) static void call_applets(int argc, char *argv[]) {
 
 int main(int argc, char *argv[]) {
 	umask(0);
-	argv0 = argv[0];
 	dload_selinux();
 	cmdline_logging();
+	init_argv0(argc, argv);
 
-	if (strcmp(basename(argv0), "magisk.bin") == 0 ||
+	if (strcmp(basename(argv[0]), "magisk.bin") == 0 ||
 			(strcmp(basename(argv[0]), "magisk") == 0
 			 && argc > 1 && argv[1][0] != '-')) {
 		--argc;
diff --git a/native/jni/core/daemon.cpp b/native/jni/core/daemon.cpp
index 7144d701e..589f7a324 100644
--- a/native/jni/core/daemon.cpp
+++ b/native/jni/core/daemon.cpp
@@ -132,7 +132,7 @@ static void main_daemon() {
 	xlisten(fd, 10);
 
 	// Change process name
-	strcpy(argv0, "magiskd");
+	set_nice_name("magiskd");
 
 	// Block all signals
 	sigset_t block_set;
diff --git a/native/jni/include/magisk.h b/native/jni/include/magisk.h
index 94b3b5262..ec31181ab 100644
--- a/native/jni/include/magisk.h
+++ b/native/jni/include/magisk.h
@@ -39,7 +39,6 @@
 #define SEPOL_PROC_DOMAIN "magisk"
 #define SEPOL_FILE_DOMAIN "magisk_file"
 
-extern char *argv0;     /* For changing process name */
 extern int SDK_INT;
 
 #define applet_names ((const char *[]) { "magisk", "su", "resetprop", "magiskhide", nullptr })
diff --git a/native/jni/utils/include/utils.h b/native/jni/utils/include/utils.h
index 11e56d36a..22bac5886 100644
--- a/native/jni/utils/include/utils.h
+++ b/native/jni/utils/include/utils.h
@@ -85,6 +85,8 @@ int fork_dont_care();
 int fork_no_zombie();
 void gen_rand_str(char *buf, int len);
 int strend(const char *s1, const char *s2);
+void init_argv0(int argc, char **argv);
+void set_nice_name(const char *name);
 
 #define getline __getline
 #define getdelim __getdelim
diff --git a/native/jni/utils/misc.cpp b/native/jni/utils/misc.cpp
index 95d41e56f..8eac4b48a 100644
--- a/native/jni/utils/misc.cpp
+++ b/native/jni/utils/misc.cpp
@@ -224,3 +224,15 @@ int new_daemon_thread(void *(*start_routine) (void *), void *arg, const pthread_
 	return ret;
 }
 
+static char *argv0;
+static size_t name_len;
+void init_argv0(int argc, char **argv) {
+	argv0 = argv[0];
+	name_len = (argv[argc - 1] - argv[0]) + strlen(argv[argc - 1]) + 1;
+}
+
+void set_nice_name(const char *name) {
+	memset(argv0, 0, name_len);
+	strlcpy(argv0, name, name_len);
+	prctl(PR_SET_NAME, name);
+}