From bade4f2c6a8dcceab4d13f23015c03f0b4af6ca7 Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Sat, 21 Aug 2021 00:58:51 -0700
Subject: [PATCH] Make xhook log as Magisk

---
 native/jni/core/core.hpp       |  1 -
 native/jni/core/logging.cpp    | 24 ++++++++++++++----------
 native/jni/external/Android.mk |  2 +-
 native/jni/include/daemon.hpp  |  2 +-
 native/jni/zygisk/entry.cpp    |  6 +++---
 5 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/native/jni/core/core.hpp b/native/jni/core/core.hpp
index 0aea2da01..4c1fe0dd1 100644
--- a/native/jni/core/core.hpp
+++ b/native/jni/core/core.hpp
@@ -8,7 +8,6 @@ extern int DAEMON_STATE;
 
 void unlock_blocks();
 void reboot();
-void magisk_logging();
 void start_log_daemon();
 void setup_logfile(bool reset);
 
diff --git a/native/jni/core/logging.cpp b/native/jni/core/logging.cpp
index 436840a4e..e66b8e4d0 100644
--- a/native/jni/core/logging.cpp
+++ b/native/jni/core/logging.cpp
@@ -149,6 +149,20 @@ static int magisk_log(int prio, const char *fmt, va_list ap) {
     return len;
 }
 
+// Used to override external C library logging
+extern "C" int magisk_log_print(int prio, const char *tag, const char *fmt, ...) {
+    char buf[4096];
+    auto len = strlcpy(buf, tag, sizeof(buf));
+    // Prevent format specifications in the tag
+    std::replace(buf, buf + len, '%', '_');
+    snprintf(buf + len, sizeof(buf) - len, ": %s", fmt);
+    va_list argv;
+    va_start(argv, fmt);
+    int ret = magisk_log(prio, buf, argv);
+    va_end(argv);
+    return ret;
+}
+
 #define mlog(prio) [](auto fmt, auto ap){ return magisk_log(ANDROID_LOG_##prio, fmt, ap); }
 void magisk_logging() {
     log_cb.d = mlog(DEBUG);
@@ -158,16 +172,6 @@ void magisk_logging() {
     log_cb.ex = nop_ex;
 }
 
-#define alog(prio) [](auto fmt, auto ap){ \
-return __android_log_vprint(ANDROID_LOG_##prio, "Magisk", fmt, ap); }
-void android_logging() {
-    log_cb.d = alog(DEBUG);
-    log_cb.i = alog(INFO);
-    log_cb.w = alog(WARN);
-    log_cb.e = alog(ERROR);
-    log_cb.ex = nop_ex;
-}
-
 void start_log_daemon() {
     int fds[2];
     if (pipe2(fds, O_CLOEXEC) == 0) {
diff --git a/native/jni/external/Android.mk b/native/jni/external/Android.mk
index 34985d154..98c00c967 100644
--- a/native/jni/external/Android.mk
+++ b/native/jni/external/Android.mk
@@ -365,7 +365,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE:= libxhook
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/xhook/libxhook/jni
 LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
-LOCAL_CFLAGS := -Wall -Wextra -Werror -fvisibility=hidden
+LOCAL_CFLAGS := -Wall -Wextra -Werror -fvisibility=hidden -D__android_log_print=magisk_log_print
 LOCAL_CONLYFLAGS := -std=c11
 LOCAL_SRC_FILES := \
     xhook/libxhook/jni/xh_log.c \
diff --git a/native/jni/include/daemon.hpp b/native/jni/include/daemon.hpp
index 50b4b9446..b10121b1e 100644
--- a/native/jni/include/daemon.hpp
+++ b/native/jni/include/daemon.hpp
@@ -48,7 +48,7 @@ enum : int {
 
 int connect_daemon(bool create = false);
 
-void android_logging();
+void magisk_logging();
 
 // Daemon handlers
 void post_fs_data(int client);
diff --git a/native/jni/zygisk/entry.cpp b/native/jni/zygisk/entry.cpp
index d317e5951..c611dbb00 100644
--- a/native/jni/zygisk/entry.cpp
+++ b/native/jni/zygisk/entry.cpp
@@ -81,7 +81,7 @@ static void inject_cleanup_wait() {
 __attribute__((constructor))
 static void inject_init() {
     if (char *env = getenv(INJECT_ENV_2)) {
-        android_logging();
+        magisk_logging();
         LOGD("zygisk: inject 2nd stage\n");
         active_threads = 1;
         unsetenv(INJECT_ENV_2);
@@ -100,7 +100,7 @@ static void inject_init() {
         active_threads++;
         new_daemon_thread(&unload_first_stage, env);
     } else if (getenv(INJECT_ENV_1)) {
-        android_logging();
+        magisk_logging();
         LOGD("zygisk: inject 1st stage\n");
 
         char *ld = getenv("LD_PRELOAD");
@@ -128,7 +128,7 @@ static void inject_init() {
 // Start code for magiskd IPC
 
 int app_process_main(int argc, char *argv[]) {
-    android_logging();
+    magisk_logging();
 
     if (int fd = connect_daemon(); fd >= 0) {
         write_int(fd, ZYGISK_REQUEST);