diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2025-04-08 10:12:20 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2025-04-09 21:35:27 +0800 |
| commit | 3be3f70ee95da03a87d94c4a714ee679a5c7b34d (patch) | |
| tree | 60dbcfbf1cff998e200460bf19a526fde967add0 /arch/x86/crypto | |
| parent | 5322584385d938773cbb562db64d8423dd5fd026 (diff) | |
crypto: x86/chacha - Restore SSSE3 fallback path
The chacha_use_simd static branch is required for x86 machines that
lack SSSE3 support. Restore it and the generic fallback code.
Reported-by: Eric Biggers <ebiggers@kernel.org>
Fixes: 9b4400215e0e ("crypto: x86/chacha - Remove SIMD fallback path")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/x86/crypto')
| -rw-r--r-- | arch/x86/crypto/chacha_glue.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c index b7fd7a1f0e15..fcc14c006bde 100644 --- a/arch/x86/crypto/chacha_glue.c +++ b/arch/x86/crypto/chacha_glue.c @@ -5,11 +5,12 @@ * Copyright (C) 2015 Martin Willi */ +#include <asm/simd.h> #include <crypto/chacha.h> +#include <linux/jump_label.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/sizes.h> -#include <asm/simd.h> asmlinkage void chacha_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src, unsigned int len, int nrounds); @@ -31,6 +32,7 @@ asmlinkage void chacha_4block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src, asmlinkage void chacha_8block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src, unsigned int len, int nrounds); +static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_simd); static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx2); static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx512vl); @@ -117,15 +119,23 @@ static void chacha_dosimd(u32 *state, u8 *dst, const u8 *src, void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds) { - kernel_fpu_begin(); - hchacha_block_ssse3(state, stream, nrounds); - kernel_fpu_end(); + if (!static_branch_likely(&chacha_use_simd)) { + hchacha_block_generic(state, stream, nrounds); + } else { + kernel_fpu_begin(); + hchacha_block_ssse3(state, stream, nrounds); + kernel_fpu_end(); + } } EXPORT_SYMBOL(hchacha_block_arch); void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, int nrounds) { + if (!static_branch_likely(&chacha_use_simd) || + bytes <= CHACHA_BLOCK_SIZE) + return chacha_crypt_generic(state, dst, src, bytes, nrounds); + do { unsigned int todo = min_t(unsigned int, bytes, SZ_4K); @@ -142,7 +152,7 @@ EXPORT_SYMBOL(chacha_crypt_arch); bool chacha_is_arch_optimized(void) { - return true; + return static_key_enabled(&chacha_use_simd); } EXPORT_SYMBOL(chacha_is_arch_optimized); @@ -151,6 +161,8 @@ static int __init chacha_simd_mod_init(void) if (!boot_cpu_has(X86_FEATURE_SSSE3)) return 0; + static_branch_enable(&chacha_use_simd); + if (boot_cpu_has(X86_FEATURE_AVX) && boot_cpu_has(X86_FEATURE_AVX2) && cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) { |