Re: [PATCH] drivers: infiniband: sw: rxe: fix kconfig dependency on CRYPTO

From: Arnd Bergmann <arnd@kernel.org>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>, Leon Romanovsky <leon@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>, Zhu Yanjun <zyjzyj2000@gmail.com>,
	Julian Braha <julianbraha@gmail.com>,
	Doug Ledford <dledford@redhat.com>,
	RDMA mailing list <linux-rdma@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] drivers: infiniband: sw: rxe: fix kconfig dependency on CRYPTO
Date: Tue, 23 Feb 2021 21:36:22 +0100	[thread overview]
Message-ID: <CAK8P3a3z0_TNWP7TAVcZC8+MDJKhAZMbQoEH8tgfLQy2MJmG0Q@mail.gmail.com> (raw)
In-Reply-To: <850d8bf2-c5a0-9fee-f95f-2dfc7d22a528@infradead.org>

On Mon, Feb 22, 2021 at 5:53 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> On 2/22/21 8:46 AM, Jason Gunthorpe wrote:
>
> > There is nearly 1000 places that use a 'select CRYPTO_*' in the
> > kernel.
> >
> > I see only 60 'select CRYPTO' statements.

I think most of these are correct, as you typically have a single
'select CRYPTO'
in combination with a couple of 'select CRYPTO_*' ones for the specific
algorithms. I just added a lot of 'select CRC32' statements to deal with
all the build failures in drivers that require this but fail to have an extra
select statement. The way I got the list was to start with 'make allmodconfig'
and then recursively disable everything that had an explicit select, until
I was left with all the modules that need it without selecting it.

The same method could be used for CONFIG_CRYPTO, but it's a few
hours of work.

> Correct. :(
> We (community) tend to fix bug reports, not do global audits
> to see what needs to be fixed (with a few exceptions).
>
>
> I'll gladly wait to see what Arnd says.

For the specific case of CRC32, it might actually a good idea to change
the code to call into the CRC32 code directly instead of the CRYPTO_CRC32
abstraction. Would that work for RDMA_RXE?

       Arnd