From d6e159bff9be42c27f4aeed48cc13fa8a07886aa Mon Sep 17 00:00:00 2001
From: LoveSy <shana@zju.edu.cn>
Date: Wed, 22 May 2024 21:39:40 +0800
Subject: [PATCH] Use pidfd in more senarios

---
 native/src/core/deny/logcat.cpp | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/native/src/core/deny/logcat.cpp b/native/src/core/deny/logcat.cpp
index fbe97be22..26bda5e29 100644
--- a/native/src/core/deny/logcat.cpp
+++ b/native/src/core/deny/logcat.cpp
@@ -2,6 +2,7 @@
 #include <string>
 #include <cinttypes>
 #include <android/log.h>
+#include <sys/syscall.h>
 
 #include <base.hpp>
 
@@ -190,18 +191,27 @@ static void process_events_buffer(struct log_msg *msg) {
                 }
 
                 char path[16];
+                ssprintf(path, sizeof(path), "/proc/%d", pid);
                 struct stat st{};
-                sprintf(path, "/proc/%d", pid);
+                int fd = syscall(__NR_pidfd_open, pid, 0);
+                if (fd > 0 && setns(fd, CLONE_NEWNS) == 0) {
+                    pid = getpid();
+                } else {
+                    close(fd);
+                    fd = -1;
+                }
                 while (read_ns(pid, &st) == 0 && it->second.st_ino == st.st_ino) {
                     if (stat(path, &st) == 0 && st.st_uid == 0) {
                         usleep(10 * 1000);
                     } else {
-                        LOGW("logcat: skip [%.*s] PID=[%d] UID=[%d]; namespace not isolated\n",
+                        LOGW("logcat: skip [%.*s] PID=[%s] UID=[%d]; namespace not isolated\n",
                              (int) proc.length(), proc.data(),
-                             pid, am_proc_start->uid.data);
+                             path + 6, am_proc_start->uid.data);
                         _exit(0);
                     }
+                    if (fd > 0) setns(fd, CLONE_NEWNS);
                 }
+                close(fd);
 
                 LOGI("logcat: revert [%.*s] PID=[%d] UID=[%d]\n",
                      (int) proc.length(), proc.data(), pid, am_proc_start->uid.data);