From: Venkat Rao Bagalkote <venka...@linux.ibm.com> Date: Fri, 12 Sep 2025 18:39:33 +0530
> Greetings!!! > > > IBM CI has reported a build warning on IBM Power Server, on linux- > next20250912 kernel. > > > gcc version 11.5.0 20240719 (Red Hat 11.5.0-2) (GCC) > > GNU ld version 2.35.2-54.el9 > > > Attached is the .config file. > > > Warnings: > > In file included from drivers/net/ethernet/intel/idpf/xdp.c:6: > drivers/net/ethernet/intel/idpf/xdp.h: In function ‘idpf_xdp_tx_xmit’: > drivers/net/ethernet/intel/idpf/xdp.h:28:20: note: the ABI of passing > aggregates with 16-byte alignment has changed in GCC 5 > 28 | static inline void idpf_xdp_tx_xmit(struct libeth_xdp_tx_desc > desc, u32 i, > | ^~~~~~~~~~~~~~~~ Yes, I do pass 16-byte variables/structures directly. I would say this warning makes no sense, due to the following reasons: 1. IIRC the minimum required GCC version for building the latest kernel is way above 5. 2. This warning should appear only with `-Wabi`, which the upstream kernel never sets. 3. Kernel is a self-contained project, this function is not uAPI, so we shouldn't care in general about backward ABI compatibility for purely in-kernel stuff. We have plenty of functions, mostly generic, which either passes or returns >= 16-byte objects, but I see this warning for the first time. Despite that my repo is attached to the open Intel CI bots infra which does daily builds on a good bunch of different architectures and toolchains (inc. GCC 8+). > > > Git bisect is pointing below commit as the first bad commit. > > > first bad commit: [cba102cd719029a10bda1d0ca00ed646796f1f21] idpf: add > support for XDP on Rx Thanks, Olek
