Re: [PATCH net-next v2 2/2] selftests: drv-net: Use cross-compilation environment for the io_uring check

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

Hi,

On 9/6/26 17:00, netdev-bot+sashiko@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential
> issue(s) to consider:
> 
> Critical: 0 · High: 0 · Medium: 1 · Low: 1
> 
> - [Medium] Incomplete fix: the capability probe still uses a different
>   compiler than the one lib.mk installs to build `iou-zcrx`, in two…
> - [Low] Missing `Fixes:` tag.
> 
> --
> 
> selftests: drv-net: Use cross-compilation environment for the io_uring check
> 
> This patch sets CC to $(CROSS_COMPILE)gcc at the top of
> tools/testing/selftests/drivers/net/hw/Makefile so that the liburing
> zero-copy capability probe (HAS_IOURING_ZCRX) is compiled with the
> cross compiler instead of make's built-in default. The override is
> guarded by ifeq ($(LLVM)$(CC),cc).
> 
> [Severity: Low]
> 
> Should this carry a Fixes: tag?  git blame on the baseline attributes the
> whole probe block, including the ifeq ($(HAS_IOURING_ZCRX),y) gating, to
> f81171fecd0c3 ("selftests: hw-net: auto-disable building the iouring C
> code").  Since no CC is set before the probe in this Makefile, in
> tools/testing/selftests/Makefile, or in lib.mk, that commit is where the
> probe started evaluating with the built-in CC=cc in cross builds:
> 
>   Fixes: f81171fecd0c3 ("selftests: hw-net: auto-disable building the iouring C code")

Yeah but OTHO this never worked, and apparently was never tested before.

> 
> On the changelog wording:
> 
>> The CC value used for the io_uring library check defaults to the host
>> compiler, which will fail in cross-compiling environments.

I'll reword yeah...

[...]

> 
> Since the probe is expanded well before include ../../../lib.mk, would it
> be possible to mirror lib.mk's own CC derivation here, or to move the probe
> after lib.mk is included, so the gate always matches the compiler that
> builds iou-zcrx?

Well this is what I wanted to avoid :(

Let me reword the commit log for V2, Matthieu if that's OK I'll also keep your
R-b, as I'll leave the code as-is unless someone has any objection ?

Maxime