Re: [PATCH v2] scripts/checkpatch: more checks on files imported from Linux

[Peter Maydell <peter.maydell@linaro.org>]

On Thu, 16 Jan 2025 at 09:26, David Woodhouse <dwmw2@infradead.org> wrote:
>
> On Thu, 2024-07-18 at 09:20 +0200, Stefano Garzarella wrote:
> > If a file imported from Linux is touched, emit a warning and suggest
> > using scripts/update-linux-headers.sh.
> >
> > Also check that updating imported files from Linux are not mixed with
> > other changes, in which case emit an error.
> >
> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
>
> This now seems to complain about a commit which simply adds a file to
> update-linux-headers.sh and simultaneously adds the newly-imported
> file. Such as commit aa274c33c39e7de981dc195abe60e1a246c9d248.
>
> Was that the intent? Do we really need to have *three* separate
> commits, one for update-linux-headers.sh, one to import the new header,
> and then the third to add the QEMU code which actually uses the new
> header?
>
> $ scripts/checkpatch.pl 0001-update-linux-headers-import-linux-kvm_para.h-header.patch
> WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
> #36:
> new file mode 100644
>
> WARNING: added, moved or deleted file(s) imported from Linux, are you using scripts/update-linux-headers.sh?
> #41: FILE: include/standard-headers/linux/kvm_para.h:1:
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
>
> ERROR: headers imported from Linux should be self-contained in a patch with no other changes
> #99: FILE: scripts/update-linux-headers.sh:63:
>                                       -e 'linux/kernel' \

Just to state for the record the conclusion of our conversation
on IRC; yes, the error is correct. Header-imports from
Linux should be in a patch of their own which has no
changes except the results of running update-linux-headers.sh
(and ideally we would not have let aa274c33c39e7 through
code review). So, yes, you have a series of three patches:
 * change update-linux-headers.sh
 * automated-change-only commit resulting from running the script
 * the change you want to make that requires the new header

thanks
-- PMM