From b55e1a39543f5e9aadf1149f8ad4bcff5cace8a4 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 12 Mar 2019 22:12:47 -0700 Subject: [PATCH] crypto: simd,testmgr - introduce crypto_simd_usable() So that the no-SIMD fallback code can be tested by the crypto self-tests, add a macro crypto_simd_usable() which wraps may_use_simd(), but also returns false if the crypto self-tests have set a per-CPU bool to disable SIMD in crypto code on the current CPU. Signed-off-by: Eric Biggers Reviewed-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- crypto/testmgr.c | 26 +++++++++++++++++++++++++- include/crypto/internal/simd.h | 24 ++++++++++++++++++++++++ 2 files changed, 49 insertions(+), 1 deletion(-) diff --git a/crypto/testmgr.c b/crypto/testmgr.c index 5d56b2990762..52417dde811f 100644 --- a/crypto/testmgr.c +++ b/crypto/testmgr.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "internal.h" @@ -52,6 +53,9 @@ MODULE_PARM_DESC(noextratests, "disable expensive crypto self-tests"); static unsigned int fuzz_iterations = 100; module_param(fuzz_iterations, uint, 0644); MODULE_PARM_DESC(fuzz_iterations, "number of fuzz test iterations"); + +DEFINE_PER_CPU(bool, crypto_simd_disabled_for_test); +EXPORT_PER_CPU_SYMBOL_GPL(crypto_simd_disabled_for_test); #endif #ifdef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS @@ -838,7 +842,27 @@ static void generate_random_testvec_config(struct testvec_config *cfg, WARN_ON_ONCE(!valid_testvec_config(cfg)); } -#endif /* CONFIG_CRYPTO_MANAGER_EXTRA_TESTS */ + +static void crypto_disable_simd_for_test(void) +{ + preempt_disable(); + __this_cpu_write(crypto_simd_disabled_for_test, true); +} + +static void crypto_reenable_simd_for_test(void) +{ + __this_cpu_write(crypto_simd_disabled_for_test, false); + preempt_enable(); +} +#else /* !CONFIG_CRYPTO_MANAGER_EXTRA_TESTS */ +static void crypto_disable_simd_for_test(void) +{ +} + +static void crypto_reenable_simd_for_test(void) +{ +} +#endif /* !CONFIG_CRYPTO_MANAGER_EXTRA_TESTS */ static int check_nonfinal_hash_op(const char *op, int err, u8 *result, unsigned int digestsize, diff --git a/include/crypto/internal/simd.h b/include/crypto/internal/simd.h index a23b18b6ad61..d2316242a988 100644 --- a/include/crypto/internal/simd.h +++ b/include/crypto/internal/simd.h @@ -6,6 +6,9 @@ #ifndef _CRYPTO_INTERNAL_SIMD_H #define _CRYPTO_INTERNAL_SIMD_H +#include +#include + /* skcipher support */ struct simd_skcipher_alg; @@ -42,4 +45,25 @@ int simd_register_aeads_compat(struct aead_alg *algs, int count, void simd_unregister_aeads(struct aead_alg *algs, int count, struct simd_aead_alg **simd_algs); +/* + * crypto_simd_usable() - is it allowed at this time to use SIMD instructions or + * access the SIMD register file? + * + * This delegates to may_use_simd(), except that this also returns false if SIMD + * in crypto code has been temporarily disabled on this CPU by the crypto + * self-tests, in order to test the no-SIMD fallback code. This override is + * currently limited to configurations where the extra self-tests are enabled, + * because it might be a bit too invasive to be part of the regular self-tests. + * + * This is a macro so that , which some architectures don't have, + * doesn't have to be included directly here. + */ +#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS +DECLARE_PER_CPU(bool, crypto_simd_disabled_for_test); +#define crypto_simd_usable() \ + (may_use_simd() && !this_cpu_read(crypto_simd_disabled_for_test)) +#else +#define crypto_simd_usable() may_use_simd() +#endif + #endif /* _CRYPTO_INTERNAL_SIMD_H */