option to compile xdp-tools with gcc?

[vincentmli]

Hi @tohojo

Happy new year! :). is it trivial to add gcc as compiler to compile xdp-tools XDP program? I am porting xdp-tools to loongarch CPU and I am unable to load the XDP program due to some loongarch CPU model not allowing unaligned memory access. the loongarch kernel maintainer suggested to check if clang has strict alignment flag to enforce alignment, according to chatgpt, clang does not have such flag, gcc has such flag -mstrict-align. so I am wondering if it is possible to add gcc as a compiler option to xdp-tools. see vincentmli/BPFire#69 for more detail.

[tohojo]

Erm, AFAICT from the issue you linked, the BPF program you're trying to load is not part of xdp-tools, so what difference would it make to change how xdp-tools is compiled?

[vincentmli]

I forked xdp-tools as clang/llvm/Makefile framework to build my XDP programs to save me coming up my own clang/llvm/Makefile... because xdp-tools allows that addition easily, and I use xdp-loader tool to load all my XDP programs, I thought it is trivial to add gcc, so why not :). I understand adding gcc does not add benefit to xdp-tools itself and may add more burden to maintain, except for my own use case.

[tohojo]

Well, if you can get it to work, feel free to open a PR - happy to take a look :)

[vincentmli]

I just found https://gcc.gnu.org/wiki/BPFBackEnd

"
The following projects are still to be ported:

xdp-tools - https://github.com/xdp-project/xdp-tools

sched_ext - https://github.com/sched-ext/scx
"

maybe they will get to it some day :)