create_elf_cache might be blocked at reading special device files

Host: x86_64-gnu-linux 6.1.0 Target: aarch64-gnu-linux 6.1.0 IDE: Xilinx SDK 2019.1 When debugging a GUI application remotely using tcf-agent, tcf connection would hang after some function call. Tcf-agent log shows that create_elf_cache is trying to read elf-header from mmap file /dev/dri/renderD128, at which seems like blocking forever.