Re: [PATCH v6 1/3] check-uapi: Introduce check-uapi.sh

From: Greg Kroah-Hartman
Date: Tue Nov 14 2023 - 07:25:07 EST


On Tue, Nov 14, 2023 at 07:10:51PM +0900, Masahiro Yamada wrote:
> On Sat, Oct 28, 2023 at 4:31 AM John Moon <quic_johmoo@xxxxxxxxxxx> wrote:
> >
> > While the kernel community has been good at maintaining backwards
> > compatibility with kernel UAPIs, it would be helpful to have a tool
> > to check if a commit introduces changes that break backwards
> > compatibility.
> >
> > To that end, introduce check-uapi.sh: a simple shell script that
> > checks for changes to UAPI headers using libabigail.
> >
> > libabigail is "a framework which aims at helping developers and
> > software distributors to spot some ABI-related issues like interface
> > incompatibility in ELF shared libraries by performing a static
> > analysis of the ELF binaries at hand."
> >
> > The script uses one of libabigail's tools, "abidiff", to compile the
> > changed header before and after the commit to detect any changes.
> >
> > abidiff "compares the ABI of two shared libraries in ELF format. It
> > emits a meaningful report describing the differences between the two
> > ABIs."
> >
> > The script also includes the ability to check the compatibility of
> > all UAPI headers across commits. This allows developers to inspect
> > the stability of the UAPIs over time.
> >
> > Signed-off-by: John Moon <quic_johmoo@xxxxxxxxxxx>
> > ---
> > - Add abidiff suppressions to filter out common things like enum
> > variants named .*_MAX being changed and expansion into padding
> > fields.
> > - Bump minimum abidiff version to 2.4 to accomodate new
> > suppressions.
> > - Add option (-i) to suppress ambiguous breaking changes.
> > - Remove printing of full file diffs when ABI breakage is found
> > as this was too noisy.
> > - Wait for all files to be checked before printing results as
> > printing from parallel threads was garbling output.
> > - Suppress all output when -q is passed.
> > - Avoid messing up user's git tree by using "git archive" instead
> > of checking out references.
>
>
>
> The code looks almost good to me.
>
> (I left some more comments below, but they are minor).
>
>
>
> Greg,
> Could you check the output from the tool?

I will, give me a chance to catch up after the merge window and this
week at Plumbers.... Should be a week or so, thanks.

greg k-h