On Sat, Apr 11, 2015 at 03:32:34PM +0200, Ard Biesheuvel wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > 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 <arnd@xxxxxxxx> > 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 <ard.biesheuvel@xxxxxxxxxx> Patch applied. -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html