From 2e299b381447a08d4ddfc026fbeda219e74edac5 Mon Sep 17 00:00:00 2001
From: vvb2060 <vvb2060@gmail.com>
Date: Mon, 20 Sep 2021 13:15:16 +0800
Subject: [PATCH] Add an old cgroup v2 path

https://android-review.googlesource.com/c/platform/system/core/+/1324649
---
 native/jni/core/daemon.cpp | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/native/jni/core/daemon.cpp b/native/jni/core/daemon.cpp
index 92d1f08d8..e4dee67bf 100644
--- a/native/jni/core/daemon.cpp
+++ b/native/jni/core/daemon.cpp
@@ -257,19 +257,20 @@ done:
     close(client);
 }
 
-static int switch_cgroup(const char *cgroup, int pid) {
+static void switch_cgroup(const char *cgroup, int pid) {
     char buf[32];
     snprintf(buf, sizeof(buf), "%s/cgroup.procs", cgroup);
-    int fd = open(buf, O_WRONLY | O_APPEND | O_CLOEXEC);
+    if (access(buf, F_OK) != 0)
+        return;
+    int fd = xopen(buf, O_WRONLY | O_APPEND | O_CLOEXEC);
     if (fd == -1)
-        return -1;
+        return;
     snprintf(buf, sizeof(buf), "%d\n", pid);
     if (xwrite(fd, buf, strlen(buf)) == -1) {
         close(fd);
-        return -1;
+        return;
     }
     close(fd);
-    return 0;
 }
 
 static void daemon_entry() {
@@ -302,8 +303,9 @@ static void daemon_entry() {
 
     // Escape from cgroup
     int pid = getpid();
-    if (switch_cgroup("/acct", pid) && switch_cgroup("/sys/fs/cgroup", pid))
-        LOGW("Can't switch cgroup\n");
+    switch_cgroup("/acct", pid);
+    switch_cgroup("/dev/cg2_bpf", pid);
+    switch_cgroup("/sys/fs/cgroup", pid);
 
     // Get self stat
     char buf[64];