On Wed, Jul 7, 2021 at 10:31 PM Nick Desaulniers
[off-list ref] wrote:

Which patch in the series adds the definition of rust_fmt_argument?
Sorry, I haven't looked through the entire series yet, but I don't
think it was an earlier patch in the series.  If it's later in the
series, you may want to rebase this to be after (or combine it with
the patch that provides the definition).  For instance, let's say the
first half of this series was accepted/merged, but not the latter
half. It would be weird to provide such definitions/calls to undefined
symbols.

It is in https://lore.kernel.org/lkml/20210704202756.29107-11-ojeda@kernel.org/#Z30rust:kernel:print.rs (local)

Yeah, perhaps it would have been better to put it in the `kernel`
crate commit alongside `include/linux/spinlock.h` and
`kernel/printk/printk.c`.

On the other hand, having C changes on other commits may be easier to
read and explain (note that compilation still works, given things are
only enabled near the end in the Kbuild commit).

Cheers,
Miguel