Re: [PATCH] crypto: arm: workaround for building with old binutils

From: Ard Biesheuvel
Date: Sat Apr 11 2015 - 03:41:27 EST

On 10 April 2015 at 21:57, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> 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.
>
> This patch uses the 'as-option' Kbuild macro to find out whether the
> support is present in the assembler, and otherwise passes a macro
> definition to each affected file, which in turn disables that code
> entirely and results in empty modules.
>
> In order to help users figure out what to do, we also add a #warning
> state in place of the removed to that tells users which version to use.
>
> 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")
>
> diff --git a/arch/arm/crypto/Makefile b/arch/arm/crypto/Makefile
> index ef46e898f98b..60f2101e0586 100644
> --- a/arch/arm/crypto/Makefile
> +++ b/arch/arm/crypto/Makefile
> @@ -25,6 +25,10 @@ sha2-arm-ce-y := sha2-ce-core.o sha2-ce-glue.o
> aes-arm-ce-y := aes-ce-core.o aes-ce-glue.o
> ghash-arm-ce-y := ghash-ce-core.o ghash-ce-glue.o
>
> +armv8-ce-flags := $(call as-option,-Wa$(comma)-mfpu=crypto-neon-fp-armv8,-DARMV8_CE_DISABLED)
> +asflags-y := $(armv8-ce-flags)
> +ccflags-y := $(armv8-ce-flags)
> +

Could you perhaps put the rules that build these modules inside a

ifneq ($(armv8-ce-flags),-DARMV8_CE_DISABLED)
...
endif

block?


> quiet_cmd_perl = PERL $@
> cmd_perl = $(PERL) $(<) > $(@)
>
> diff --git a/arch/arm/crypto/aes-ce-core.S b/arch/arm/crypto/aes-ce-core.S
> index 8cfa468ee570..f2132ba91353 100644
> --- a/arch/arm/crypto/aes-ce-core.S
> +++ b/arch/arm/crypto/aes-ce-core.S
> @@ -8,11 +8,14 @@
> * published by the Free Software Foundation.
> */
>
> +#ifdef ARMV8_CE_DISABLED
> +#warning ARMv8 Crypto Extensions need binutils 2.23 or higher
> +#else
> +
> #include <linux/linkage.h>
> #include <asm/assembler.h>
>
> .text
> - .fpu crypto-neon-fp-armv8
> .align 3
>
> .macro enc_round, state, key
> @@ -516,3 +519,5 @@ ENTRY(ce_aes_invert)
> vst1.8 {q0}, [r0]
> bx lr
> ENDPROC(ce_aes_invert)
> +
> +#endif
> diff --git a/arch/arm/crypto/aes-ce-glue.c b/arch/arm/crypto/aes-ce-glue.c
> index b445a5d56f43..4cba201a64a9 100644
> --- a/arch/arm/crypto/aes-ce-glue.c
> +++ b/arch/arm/crypto/aes-ce-glue.c
> @@ -510,13 +510,16 @@ static struct crypto_alg aes_algs[] = { {
>
> static int __init aes_init(void)
> {
> - if (!(elf_hwcap2 & HWCAP2_AES))
> + if (IS_ENABLED(ARMV8_CE_DISABLED) || !(elf_hwcap2 & HWCAP2_AES))
> return -ENODEV;
> return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
> }
>
> static void __exit aes_exit(void)
> {
> + if (IS_ENABLED(ARMV8_CE_DISABLED))
> + return;
> +
> crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
> }
>
> diff --git a/arch/arm/crypto/ghash-ce-core.S b/arch/arm/crypto/ghash-ce-core.S
> index f6ab8bcc9efe..4fe75df41162 100644
> --- a/arch/arm/crypto/ghash-ce-core.S
> +++ b/arch/arm/crypto/ghash-ce-core.S
> @@ -8,6 +8,10 @@
> * by the Free Software Foundation.
> */
>
> +#ifdef ARMV8_CE_DISABLED
> +#warning ARMv8 Crypto Extensions need binutils 2.23 or higher
> +#else
> +
> #include <linux/linkage.h>
> #include <asm/assembler.h>
>
> @@ -33,8 +37,6 @@
> XH_L .req d14
>
> .text
> - .fpu crypto-neon-fp-armv8
> -
> /*
> * void pmull_ghash_update(int blocks, u64 dg[], const char *src,
> * struct ghash_key const *k, const char *head)
> @@ -92,3 +94,5 @@ ENTRY(pmull_ghash_update)
> vst1.64 {XL}, [r1]
> bx lr
> ENDPROC(pmull_ghash_update)
> +
> +#endif
> diff --git a/arch/arm/crypto/ghash-ce-glue.c b/arch/arm/crypto/ghash-ce-glue.c
> index 03a39fe29246..880afe904e5d 100644
> --- a/arch/arm/crypto/ghash-ce-glue.c
> +++ b/arch/arm/crypto/ghash-ce-glue.c
> @@ -293,7 +293,7 @@ static int __init ghash_ce_mod_init(void)
> {
> int err;
>
> - if (!(elf_hwcap2 & HWCAP2_PMULL))
> + if (IS_ENABLED(ARMV8_CE_DISABLED) || !(elf_hwcap2 & HWCAP2_AES))
> return -ENODEV;
>
> err = crypto_register_shash(&ghash_alg);
> @@ -312,6 +312,9 @@ err_shash:
>
> static void __exit ghash_ce_mod_exit(void)
> {
> + if (IS_ENABLED(ARMV8_CE_DISABLED))
> + return;
> +
> crypto_unregister_ahash(&ghash_async_alg);
> crypto_unregister_shash(&ghash_alg);
> }
> diff --git a/arch/arm/crypto/sha1-ce-core.S b/arch/arm/crypto/sha1-ce-core.S
> index 4aad520935d8..ab0fe554a6cf 100644
> --- a/arch/arm/crypto/sha1-ce-core.S
> +++ b/arch/arm/crypto/sha1-ce-core.S
> @@ -9,11 +9,14 @@
> * published by the Free Software Foundation.
> */
>
> +#ifdef ARMV8_CE_DISABLED
> +#warning ARMv8 Crypto Extensions need binutils 2.23 or higher
> +#else
> +
> #include <linux/linkage.h>
> #include <asm/assembler.h>
>
> .text
> - .fpu crypto-neon-fp-armv8
>
> k0 .req q0
> k1 .req q1
> @@ -132,3 +135,5 @@ ENTRY(sha1_ce_transform)
> vstr dgbs, [r2, #16]
> bx lr
> ENDPROC(sha1_ce_transform)
> +
> +#endif
> diff --git a/arch/arm/crypto/sha1-ce-glue.c b/arch/arm/crypto/sha1-ce-glue.c
> index a9dd90df9fd7..045cabad9296 100644
> --- a/arch/arm/crypto/sha1-ce-glue.c
> +++ b/arch/arm/crypto/sha1-ce-glue.c
> @@ -136,13 +136,16 @@ static struct shash_alg alg = {
>
> static int __init sha1_ce_mod_init(void)
> {
> - if (!(elf_hwcap2 & HWCAP2_SHA1))
> + if (IS_ENABLED(ARMV8_CE_DISABLED) || !(elf_hwcap2 & HWCAP2_AES))
> return -ENODEV;
> return crypto_register_shash(&alg);
> }
>
> static void __exit sha1_ce_mod_fini(void)
> {
> + if (IS_ENABLED(ARMV8_CE_DISABLED))
> + return;
> +
> crypto_unregister_shash(&alg);
> }
>
> diff --git a/arch/arm/crypto/sha2-ce-core.S b/arch/arm/crypto/sha2-ce-core.S
> index 96af09fe957b..3db821c5f4cd 100644
> --- a/arch/arm/crypto/sha2-ce-core.S
> +++ b/arch/arm/crypto/sha2-ce-core.S
> @@ -9,11 +9,14 @@
> * published by the Free Software Foundation.
> */
>
> +#ifdef ARMV8_CE_DISABLED
> +#warning ARMv8 Crypto Extensions need binutils 2.23 or higher
> +#else
> +
> #include <linux/linkage.h>
> #include <asm/assembler.h>
>
> .text
> - .fpu crypto-neon-fp-armv8
>
> k0 .req q7
> k1 .req q8
> @@ -132,3 +135,5 @@ ENTRY(sha2_ce_transform)
> vst1.32 {dga-dgb}, [r2]
> bx lr
> ENDPROC(sha2_ce_transform)
> +
> +#endif
> diff --git a/arch/arm/crypto/sha2-ce-glue.c b/arch/arm/crypto/sha2-ce-glue.c
> index 0449eca3aab3..3f8010837310 100644
> --- a/arch/arm/crypto/sha2-ce-glue.c
> +++ b/arch/arm/crypto/sha2-ce-glue.c
> @@ -189,13 +189,16 @@ static struct shash_alg algs[] = { {
>
> static int __init sha2_ce_mod_init(void)
> {
> - if (!(elf_hwcap2 & HWCAP2_SHA2))
> + if (IS_ENABLED(ARMV8_CE_DISABLED) || !(elf_hwcap2 & HWCAP2_AES))
> return -ENODEV;
> return crypto_register_shashes(algs, ARRAY_SIZE(algs));
> }
>
> static void __exit sha2_ce_mod_fini(void)
> {
> + if (IS_ENABLED(ARMV8_CE_DISABLED))
> + return;
> +
> crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
> }
>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/