From: Venkat <[email protected]> Date: Mon, 13 Oct 2025 09:27:14 +0530
> > >> On 12 Sep 2025, at 7:00 PM, Alexander Lobakin <[email protected]> >> wrote: >> >> From: Venkat Rao Bagalkote <[email protected]> >> 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 BTW wait, "note"? It's not even a warning? >>> 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. > > Now, this warning is seen on upstream kernel also. Then how to reproduce it? I've never seen a single report from the upstream CI bots which would point out to such warning. Could RH enable some additional output by default in their GCC? > > Not sure if this is something we need to fix it or suppress the warning? There's nothing to fix nor suppress. > > Regards, > Venkat. > >> 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+). Thanks, Olek
