Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <260b4b85d714df822da259554ef8cc2873f3096f.camel@HansenPartnership.com>
Subject: Re: [PATCH 0/1] Add explicit error for missing CONFIG_ASN1
From:   James Bottomley <James.Bottomley@HansenPartnership.com>
To:     Randy Dunlap <rdunlap@infradead.org>, linux-kbuild@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Masahiro Yamada <masahiroy@kernel.org>
Date:   Tue, 22 Sep 2020 12:19:34 -0700
In-Reply-To: <dfae4d4f-aa96-674d-93b1-d4c097e720e4@infradead.org>
References: <20200922155341.17906-1-James.Bottomley@HansenPartnership.com>
         <dfae4d4f-aa96-674d-93b1-d4c097e720e4@infradead.org>
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.34.4 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Tue, 2020-09-22 at 11:54 -0700, Randy Dunlap wrote:
> On 9/22/20 8:53 AM, James Bottomley wrote:
> > I recently ran into this as an error from 0day.  On x86 it's pretty
> > much impossible to build a configuration where CONFIG_ASN1 isn't
> > set, so you rarely notice a problem using the ASN.1 compiler
> > because something else has selected it.  However, this compiler is
> > never built if CONFIG_ASN1 isn't set and the error you get from
> > kbuild is particularly unhelpful:
> > 
> >    make[4]: *** No rule to make target 'security/keys/trusted-
> > keys/tpm2key.asn1.o', needed by 'security/keys/trusted-keys/built-
> > in.a'.
> >    make[4]: *** [scripts/Makefile.build:283: security/keys/trusted-
> > keys/trusted_tpm2.o] Error 1
> >    make[4]: Target '__build' not remade because of errors.
> > 
> > This patch changes the above error to the much easier to diagnose:
> > 
> >    scripts/Makefile.build:387: *** CONFIG_ASN1 must be defined for
> > the asn1_compiler.  Stop.
> >    make[3]: *** [scripts/Makefile.build:505: security/keys/trusted-
> > keys] Error 2
> > 
> > James
> > 
> > ---
> > 
> > James Bottomley (1):
> >   Makefile.build: Add an explicit error for missing ASN.1 compiler
> > 
> >  scripts/Makefile.build | 5 +++++
> >  1 file changed, 5 insertions(+)
> 
> Is there a missing
> 	select ASN1
> somewhere?

You mean in the build used to produce the errors above?  Yes, so the
patch is to make the problem more explicit.

James