kernel: increase reliability, add ksu_access_ok to simplify

Co-authored-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
Signed-off-by: rsuntk <rsuntk@yukiprjkt.my.id>

kernel/kernel_compat.c

@@ -178,3 +178,12 @@ long ksu_strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
 	return ret;
 }
 #endif
+
+int ksu_access_ok(const void *addr, unsigned long size)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
+	return access_ok(addr, size);
+#else
+	return access_ok(VERIFY_READ, addr, size);
+#endif
+}