On Fri, 22 Nov 2019 at 10:46, Jason A. Donenfeld <Jason@xxxxxxxxx> wrote:
>
> For glue code that's used by Zinc, the actual Crypto API functions might
> not necessarily exist, and don't need to exist either. Before this
> patch, there are valid build configurations that lead to a unbuildable
> kernel. This fixes it to conditionalize those symbols on the existence
> of the proper config entry.
>
> Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
> ---
> Changes v2->v3:
> - v2 was a dud, with a find and replace operation gone wild. v3 is
> what v2 should have been.
> Changes v1->v2:
> - Discussing with Ard on IRC, we concluded that IS_REACHABLE makes
> more sense than IS_ENABLED.
>
Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
with the note that with this arrangement, e.g., the accelerated
Curve25519 code will not be exposed via the CRYPTO_KPP interface if
the former is builtin while the latter is built as a module. This is
somewhat related to how the accelerated library code interacts with
builtin generic code, for which I added some Kconfig dependencies, and
which we should be able to revisit this once support for static calls
has made it into mainline.
> arch/arm/crypto/chacha-glue.c | 26 ++++++++++++++++----------
> arch/arm/crypto/curve25519-glue.c | 5 +++--
> arch/arm/crypto/poly1305-glue.c | 9 ++++++---
> arch/arm64/crypto/chacha-neon-glue.c | 5 +++--
> arch/arm64/crypto/poly1305-glue.c | 5 +++--
> arch/mips/crypto/chacha-glue.c | 6 ++++--
> arch/mips/crypto/poly1305-glue.c | 6 ++++--
> arch/x86/crypto/blake2s-glue.c | 6 ++++--
> arch/x86/crypto/chacha_glue.c | 6 ++++--
> arch/x86/crypto/curve25519-x86_64.c | 7 ++++---
> arch/x86/crypto/poly1305_glue.c | 5 +++--
> 11 files changed, 54 insertions(+), 32 deletions(-)
>
> diff --git a/arch/arm/crypto/chacha-glue.c b/arch/arm/crypto/chacha-glue.c
> index 3f0c057aa050..6ebbb2b241d2 100644
> --- a/arch/arm/crypto/chacha-glue.c
> +++ b/arch/arm/crypto/chacha-glue.c
> @@ -286,11 +286,13 @@ static struct skcipher_alg neon_algs[] = {
>
> static int __init chacha_simd_mod_init(void)
> {
> - int err;
> + int err = 0;
>
> - err = crypto_register_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
> - if (err)
> - return err;
> + if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) {
> + err = crypto_register_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
> + if (err)
> + return err;
> + }
>
> if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) {
> int i;
> @@ -310,18 +312,22 @@ static int __init chacha_simd_mod_init(void)
> static_branch_enable(&use_neon);
> }
>
> - err = crypto_register_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
> - if (err)
> - crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
> + if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) {
> + err = crypto_register_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
> + if (err)
> + crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
> + }
> }
> return err;
> }
>
> static void __exit chacha_simd_mod_fini(void)
> {
> - crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
> - if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON))
> - crypto_unregister_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
> + if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) {
> + crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
> + if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON))
> + crypto_unregister_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
> + }
> }
>
> module_init(chacha_simd_mod_init);
> diff --git a/arch/arm/crypto/curve25519-glue.c b/arch/arm/crypto/curve25519-glue.c
> index 2e9e12d2f642..f3f42cf3b893 100644
> --- a/arch/arm/crypto/curve25519-glue.c
> +++ b/arch/arm/crypto/curve25519-glue.c
> @@ -108,14 +108,15 @@ static int __init mod_init(void)
> {
> if (elf_hwcap & HWCAP_NEON) {
> static_branch_enable(&have_neon);
> - return crypto_register_kpp(&curve25519_alg);
> + return IS_REACHABLE(CONFIG_CRYPTO_KPP) ?
> + crypto_register_kpp(&curve25519_alg) : 0;
> }
> return 0;
> }
>
> static void __exit mod_exit(void)
> {
> - if (elf_hwcap & HWCAP_NEON)
> + if (IS_REACHABLE(CONFIG_CRYPTO_KPP) && elf_hwcap & HWCAP_NEON)
> crypto_unregister_kpp(&curve25519_alg);
> }
>
> diff --git a/arch/arm/crypto/poly1305-glue.c b/arch/arm/crypto/poly1305-glue.c
> index 74a725ac89c9..abe3f2d587dc 100644
> --- a/arch/arm/crypto/poly1305-glue.c
> +++ b/arch/arm/crypto/poly1305-glue.c
> @@ -249,16 +249,19 @@ static int __init arm_poly1305_mod_init(void)
> if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
> (elf_hwcap & HWCAP_NEON))
> static_branch_enable(&have_neon);
> - else
> + else if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
> /* register only the first entry */
> return crypto_register_shash(&arm_poly1305_algs[0]);
>
> - return crypto_register_shashes(arm_poly1305_algs,
> - ARRAY_SIZE(arm_poly1305_algs));
> + return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
> + crypto_register_shashes(arm_poly1305_algs,
> + ARRAY_SIZE(arm_poly1305_algs)) : 0;
> }
>
> static void __exit arm_poly1305_mod_exit(void)
> {
> + if (!IS_REACHABLE(CONFIG_CRYPTO_HASH))
> + return;
> if (!static_branch_likely(&have_neon)) {
> crypto_unregister_shash(&arm_poly1305_algs[0]);
> return;
> diff --git a/arch/arm64/crypto/chacha-neon-glue.c b/arch/arm64/crypto/chacha-neon-glue.c
> index b08029d7bde6..c1f9660d104c 100644
> --- a/arch/arm64/crypto/chacha-neon-glue.c
> +++ b/arch/arm64/crypto/chacha-neon-glue.c
> @@ -211,12 +211,13 @@ static int __init chacha_simd_mod_init(void)
>
> static_branch_enable(&have_neon);
>
> - return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
> + return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
> + crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
> }
>
> static void __exit chacha_simd_mod_fini(void)
> {
> - if (cpu_have_named_feature(ASIMD))
> + if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && cpu_have_named_feature(ASIMD))
> crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
> }
>
> diff --git a/arch/arm64/crypto/poly1305-glue.c b/arch/arm64/crypto/poly1305-glue.c
> index dd843d0ee83a..83a2338a8826 100644
> --- a/arch/arm64/crypto/poly1305-glue.c
> +++ b/arch/arm64/crypto/poly1305-glue.c
> @@ -220,12 +220,13 @@ static int __init neon_poly1305_mod_init(void)
>
> static_branch_enable(&have_neon);
>
> - return crypto_register_shash(&neon_poly1305_alg);
> + return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
> + crypto_register_shash(&neon_poly1305_alg) : 0;
> }
>
> static void __exit neon_poly1305_mod_exit(void)
> {
> - if (cpu_have_named_feature(ASIMD))
> + if (IS_REACHABLE(CONFIG_CRYPTO_HASH) && cpu_have_named_feature(ASIMD))
> crypto_unregister_shash(&neon_poly1305_alg);
> }
>
> diff --git a/arch/mips/crypto/chacha-glue.c b/arch/mips/crypto/chacha-glue.c
> index 779e399c9bef..d1fd23e6ef84 100644
> --- a/arch/mips/crypto/chacha-glue.c
> +++ b/arch/mips/crypto/chacha-glue.c
> @@ -128,12 +128,14 @@ static struct skcipher_alg algs[] = {
>
> static int __init chacha_simd_mod_init(void)
> {
> - return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
> + return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
> + crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
> }
>
> static void __exit chacha_simd_mod_fini(void)
> {
> - crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
> + if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER))
> + crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
> }
>
> module_init(chacha_simd_mod_init);
> diff --git a/arch/mips/crypto/poly1305-glue.c b/arch/mips/crypto/poly1305-glue.c
> index b759b6ccc361..b37d29cf5d0a 100644
> --- a/arch/mips/crypto/poly1305-glue.c
> +++ b/arch/mips/crypto/poly1305-glue.c
> @@ -187,12 +187,14 @@ static struct shash_alg mips_poly1305_alg = {
>
> static int __init mips_poly1305_mod_init(void)
> {
> - return crypto_register_shash(&mips_poly1305_alg);
> + return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
> + crypto_register_shash(&mips_poly1305_alg) : 0;
> }
>
> static void __exit mips_poly1305_mod_exit(void)
> {
> - crypto_unregister_shash(&mips_poly1305_alg);
> + if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
> + crypto_unregister_shash(&mips_poly1305_alg);
> }
>
> module_init(mips_poly1305_mod_init);
> diff --git a/arch/x86/crypto/blake2s-glue.c b/arch/x86/crypto/blake2s-glue.c
> index 4a37ba7cdbe5..1d9ff8a45e1f 100644
> --- a/arch/x86/crypto/blake2s-glue.c
> +++ b/arch/x86/crypto/blake2s-glue.c
> @@ -210,12 +210,14 @@ static int __init blake2s_mod_init(void)
> XFEATURE_MASK_AVX512, NULL))
> static_branch_enable(&blake2s_use_avx512);
>
> - return crypto_register_shashes(blake2s_algs, ARRAY_SIZE(blake2s_algs));
> + return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
> + crypto_register_shashes(blake2s_algs,
> + ARRAY_SIZE(blake2s_algs)) : 0;
> }
>
> static void __exit blake2s_mod_exit(void)
> {
> - if (boot_cpu_has(X86_FEATURE_SSSE3))
> + if (IS_REACHABLE(CONFIG_CRYPTO_HASH) && boot_cpu_has(X86_FEATURE_SSSE3))
> crypto_unregister_shashes(blake2s_algs, ARRAY_SIZE(blake2s_algs));
> }
>
> diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c
> index b391e13a9e41..ce67bc8a9f4e 100644
> --- a/arch/x86/crypto/chacha_glue.c
> +++ b/arch/x86/crypto/chacha_glue.c
> @@ -299,12 +299,14 @@ static int __init chacha_simd_mod_init(void)
> boot_cpu_has(X86_FEATURE_AVX512BW)) /* kmovq */
> static_branch_enable(&chacha_use_avx512vl);
> }
> - return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
> + return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
> + crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
> }
>
> static void __exit chacha_simd_mod_fini(void)
> {
> - crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
> + if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER))
> + crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
> }
>
> module_init(chacha_simd_mod_init);
> diff --git a/arch/x86/crypto/curve25519-x86_64.c b/arch/x86/crypto/curve25519-x86_64.c
> index a52a3fb15727..eec7d2d24239 100644
> --- a/arch/x86/crypto/curve25519-x86_64.c
> +++ b/arch/x86/crypto/curve25519-x86_64.c
> @@ -2457,13 +2457,14 @@ static int __init curve25519_mod_init(void)
> static_branch_enable(&curve25519_use_adx);
> else
> return 0;
> - return crypto_register_kpp(&curve25519_alg);
> + return IS_REACHABLE(CONFIG_CRYPTO_KPP) ?
> + crypto_register_kpp(&curve25519_alg) : 0;
> }
>
> static void __exit curve25519_mod_exit(void)
> {
> - if (boot_cpu_has(X86_FEATURE_BMI2) ||
> - boot_cpu_has(X86_FEATURE_ADX))
> + if (IS_REACHABLE(CONFIG_CRYPTO_KPP) &&
> + (boot_cpu_has(X86_FEATURE_BMI2) || boot_cpu_has(X86_FEATURE_ADX)))
> crypto_unregister_kpp(&curve25519_alg);
> }
>
> diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c
> index 370cd88068ec..0cc4537e6617 100644
> --- a/arch/x86/crypto/poly1305_glue.c
> +++ b/arch/x86/crypto/poly1305_glue.c
> @@ -224,12 +224,13 @@ static int __init poly1305_simd_mod_init(void)
> cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL))
> static_branch_enable(&poly1305_use_avx2);
>
> - return crypto_register_shash(&alg);
> + return IS_REACHABLE(CONFIG_CRYPTO_HASH) ? crypto_register_shash(&alg) : 0;
> }
>
> static void __exit poly1305_simd_mod_exit(void)
> {
> - crypto_unregister_shash(&alg);
> + if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
> + crypto_unregister_shash(&alg);
> }
>
> module_init(poly1305_simd_mod_init);
> --
> 2.24.0
>
