Use LD_PRELOAD to intercept sepolicy on 2SI init

native/jni/init/preload.c

@@ -0,0 +1,23 @@
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <dlfcn.h>
+
+int security_load_policy(void *data, size_t len) {
+    // Make sure our next exec won't get bugged
+    unsetenv("LD_PRELOAD");
+    unlink("/dev/preload.so");
+
+    int (*load_policy)(void *, size_t) = dlsym(RTLD_NEXT, "security_load_policy");
+    // Skip checking errors, because if we cannot find the symbol, there
+    // isn't much we can do other than crashing anyways.
+    int result = load_policy(data, len);
+
+    // Wait for ack
+    int fd = open("/sys/fs/selinux/enforce", O_RDONLY);
+    char c;
+    read(fd, &c, 1);
+    close(fd);
+
+    return result;
+}