From mboxrd@z Thu Jan 1 00:00:00 1970 From: Herbert Xu Subject: Re: [PATCH] crypto: arm: workaround for building with old binutils Date: Mon, 13 Apr 2015 12:12:37 +0800 Message-ID: <20150413041236.GA11091@gondor.apana.org.au> References: <1428759154-16251-1-git-send-email-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux@arm.linux.org.uk, linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, davem@davemloft.net, arnd@arndb.de To: Ard Biesheuvel Return-path: Content-Disposition: inline In-Reply-To: <1428759154-16251-1-git-send-email-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Sat, Apr 11, 2015 at 03:32:34PM +0200, Ard Biesheuvel wrote: > From: Arnd Bergmann > > How about something like this: > > A warning will be emitted by make when descending into the arch/arm/crypto > directory, but only if any ARMv8 Crypto modules were in fact selected. > > /home/ard/linux-2.6/arch/arm/crypto/Makefile:22: These ARMv8 Crypto Extensions modules need binutils 2.23 or higher > /home/ard/linux-2.6/arch/arm/crypto/Makefile:23: aes-arm-ce.o sha1-arm-ce.o sha2-arm-ce.o ghash-arm-ce.o > > > ----------------->8------------------ > Old versions of binutils (before 2.23) do not yet understand the > crypto-neon-fp-armv8 fpu instructions, and an attempt to build these > files results in a build failure: > > arch/arm/crypto/aes-ce-core.S:133: Error: selected processor does not support ARM mode `vld1.8 {q10-q11},[ip]!' > arch/arm/crypto/aes-ce-core.S:133: Error: bad instruction `aese.8 q0,q8' > arch/arm/crypto/aes-ce-core.S:133: Error: bad instruction `aesmc.8 q0,q0' > arch/arm/crypto/aes-ce-core.S:133: Error: bad instruction `aese.8 q0,q9' > arch/arm/crypto/aes-ce-core.S:133: Error: bad instruction `aesmc.8 q0,q0' > > Since the affected versions are still in widespread use, and this breaks > 'allmodconfig' builds, we should try to at least get a successful kernel > build. Unfortunately, I could not come up with a way to make the Kconfig > symbol depend on the binutils version, which would be the nicest solution. > > Instead, this patch uses the 'as-instr' Kbuild macro to find out whether > the support is present in the assembler, and otherwise emits a non-fatal > warning indicating which selected modules could not be built. > > Signed-off-by: Arnd Bergmann > Link: http://storage.kernelci.org/next/next-20150410/arm-allmodconfig/build.log > Fixes: 864cbeed4ab22d ("crypto: arm - add support for SHA1 using ARMv8 Crypto Instructions") > [ard.biesheuvel: > - omit modules entirely instead of building empty ones if binutils is too old > - update commit log accordingly] > Signed-off-by: Ard Biesheuvel Patch applied. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt