The initial Zinc patchset, after some mailing list discussion, contained code to ensure that kernel_fpu_enable would not be kept on for more than a 4k chunk, since it disables preemption. The choice of 4k isn't totally scientific, but it's not a bad guess either, and it's what's used in both the x86 poly1305, blake2s, and nhpoly1305 code already (in the form of PAGE_SIZE, which this commit corrects to be explicitly 4k).
Ard did some back of the envelope calculations and found that at 5 cycles/byte (overestimate) on a 1ghz processor (pretty slow), 4k means we have a maximum preemption disabling of 20us, which Sebastian confirmed was probably a good limit.
Unfortunately the chunking appears to have been left out of the final patchset that added the glue code. So, this commit adds it back in.
Fixes: 84e03fa39fbe ("crypto: x86/chacha - expose SIMD ChaCha routine as library function") Fixes: b3aad5bad26a ("crypto: arm64/chacha - expose arm64 ChaCha routine as library function") Fixes: a44a3430d71b ("crypto: arm/chacha - expose ARM ChaCha routine as library function") Fixes: d7d7b8535662 ("crypto: x86/poly1305 - wire up faster implementations for kernel") Fixes: f569ca164751 ("crypto: arm64/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation") Fixes: a6b803b3ddc7 ("crypto: arm/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation") Fixes: 0f961f9f670e ("crypto: x86/nhpoly1305 - add AVX2 accelerated NHPoly1305") Fixes: 012c82388c03 ("crypto: x86/nhpoly1305 - add SSE2 accelerated NHPoly1305") Fixes: a00fa0c88774 ("crypto: arm64/nhpoly1305 - add NEON-accelerated NHPoly1305") Fixes: 16aae3595a9d ("crypto: arm/nhpoly1305 - add NEON-accelerated NHPoly1305") Fixes: ed0356eda153 ("crypto: blake2s - x86_64 SIMD implementation") Cc: Eric Biggers ebiggers@google.com Cc: Ard Biesheuvel ardb@kernel.org Cc: Sebastian Andrzej Siewior bigeasy@linutronix.de Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com --- Changes v1->v2: - [Ard] Use explicit 4k chunks instead of PAGE_SIZE. - [Eric] Prefer do-while over for (;;).
arch/arm/crypto/chacha-glue.c | 14 +++++++++++--- arch/arm/crypto/nhpoly1305-neon-glue.c | 2 +- arch/arm/crypto/poly1305-glue.c | 15 +++++++++++---- arch/arm64/crypto/chacha-neon-glue.c | 14 +++++++++++--- arch/arm64/crypto/nhpoly1305-neon-glue.c | 2 +- arch/arm64/crypto/poly1305-glue.c | 15 +++++++++++---- arch/x86/crypto/blake2s-glue.c | 10 ++++------ arch/x86/crypto/chacha_glue.c | 14 +++++++++++--- arch/x86/crypto/nhpoly1305-avx2-glue.c | 2 +- arch/x86/crypto/nhpoly1305-sse2-glue.c | 2 +- arch/x86/crypto/poly1305_glue.c | 13 ++++++------- 11 files changed, 69 insertions(+), 34 deletions(-)
diff --git a/arch/arm/crypto/chacha-glue.c b/arch/arm/crypto/chacha-glue.c index 6fdb0ac62b3d..59da6c0b63b6 100644 --- a/arch/arm/crypto/chacha-glue.c +++ b/arch/arm/crypto/chacha-glue.c @@ -91,9 +91,17 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, return; }
- kernel_neon_begin(); - chacha_doneon(state, dst, src, bytes, nrounds); - kernel_neon_end(); + do { + unsigned int todo = min_t(unsigned int, bytes, SZ_4K); + + kernel_neon_begin(); + chacha_doneon(state, dst, src, todo, nrounds); + kernel_neon_end(); + + bytes -= todo; + src += todo; + dst += todo; + } while (bytes); } EXPORT_SYMBOL(chacha_crypt_arch);
diff --git a/arch/arm/crypto/nhpoly1305-neon-glue.c b/arch/arm/crypto/nhpoly1305-neon-glue.c index ae5aefc44a4d..ffa8d73fe722 100644 --- a/arch/arm/crypto/nhpoly1305-neon-glue.c +++ b/arch/arm/crypto/nhpoly1305-neon-glue.c @@ -30,7 +30,7 @@ static int nhpoly1305_neon_update(struct shash_desc *desc, return crypto_nhpoly1305_update(desc, src, srclen);
do { - unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE); + unsigned int n = min_t(unsigned int, srclen, SZ_4K);
kernel_neon_begin(); crypto_nhpoly1305_update_helper(desc, src, n, _nh_neon); diff --git a/arch/arm/crypto/poly1305-glue.c b/arch/arm/crypto/poly1305-glue.c index ceec04ec2f40..13cfef4ae22e 100644 --- a/arch/arm/crypto/poly1305-glue.c +++ b/arch/arm/crypto/poly1305-glue.c @@ -160,13 +160,20 @@ void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src, unsigned int len = round_down(nbytes, POLY1305_BLOCK_SIZE);
if (static_branch_likely(&have_neon) && do_neon) { - kernel_neon_begin(); - poly1305_blocks_neon(&dctx->h, src, len, 1); - kernel_neon_end(); + do { + unsigned int todo = min_t(unsigned int, len, SZ_4K); + + kernel_neon_begin(); + poly1305_blocks_neon(&dctx->h, src, todo, 1); + kernel_neon_end(); + + len -= todo; + src += todo; + } while (len); } else { poly1305_blocks_arm(&dctx->h, src, len, 1); + src += len; } - src += len; nbytes %= POLY1305_BLOCK_SIZE; }
diff --git a/arch/arm64/crypto/chacha-neon-glue.c b/arch/arm64/crypto/chacha-neon-glue.c index 37ca3e889848..af2bbca38e70 100644 --- a/arch/arm64/crypto/chacha-neon-glue.c +++ b/arch/arm64/crypto/chacha-neon-glue.c @@ -87,9 +87,17 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, !crypto_simd_usable()) return chacha_crypt_generic(state, dst, src, bytes, nrounds);
- kernel_neon_begin(); - chacha_doneon(state, dst, src, bytes, nrounds); - kernel_neon_end(); + do { + unsigned int todo = min_t(unsigned int, bytes, SZ_4K); + + kernel_neon_begin(); + chacha_doneon(state, dst, src, todo, nrounds); + kernel_neon_end(); + + bytes -= todo; + src += todo; + dst += todo; + } while (bytes); } EXPORT_SYMBOL(chacha_crypt_arch);
diff --git a/arch/arm64/crypto/nhpoly1305-neon-glue.c b/arch/arm64/crypto/nhpoly1305-neon-glue.c index 895d3727c1fb..c5405e6a6db7 100644 --- a/arch/arm64/crypto/nhpoly1305-neon-glue.c +++ b/arch/arm64/crypto/nhpoly1305-neon-glue.c @@ -30,7 +30,7 @@ static int nhpoly1305_neon_update(struct shash_desc *desc, return crypto_nhpoly1305_update(desc, src, srclen);
do { - unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE); + unsigned int n = min_t(unsigned int, srclen, SZ_4K);
kernel_neon_begin(); crypto_nhpoly1305_update_helper(desc, src, n, _nh_neon); diff --git a/arch/arm64/crypto/poly1305-glue.c b/arch/arm64/crypto/poly1305-glue.c index e97b092f56b8..f33ada70c4ed 100644 --- a/arch/arm64/crypto/poly1305-glue.c +++ b/arch/arm64/crypto/poly1305-glue.c @@ -143,13 +143,20 @@ void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src, unsigned int len = round_down(nbytes, POLY1305_BLOCK_SIZE);
if (static_branch_likely(&have_neon) && crypto_simd_usable()) { - kernel_neon_begin(); - poly1305_blocks_neon(&dctx->h, src, len, 1); - kernel_neon_end(); + do { + unsigned int todo = min_t(unsigned int, len, SZ_4K); + + kernel_neon_begin(); + poly1305_blocks_neon(&dctx->h, src, todo, 1); + kernel_neon_end(); + + len -= todo; + src += todo; + } while (len); } else { poly1305_blocks(&dctx->h, src, len, 1); + src += len; } - src += len; nbytes %= POLY1305_BLOCK_SIZE; }
diff --git a/arch/x86/crypto/blake2s-glue.c b/arch/x86/crypto/blake2s-glue.c index 06ef2d4a4701..6737bcea1fa1 100644 --- a/arch/x86/crypto/blake2s-glue.c +++ b/arch/x86/crypto/blake2s-glue.c @@ -32,16 +32,16 @@ void blake2s_compress_arch(struct blake2s_state *state, const u32 inc) { /* SIMD disables preemption, so relax after processing each page. */ - BUILD_BUG_ON(PAGE_SIZE / BLAKE2S_BLOCK_SIZE < 8); + BUILD_BUG_ON(SZ_4K / BLAKE2S_BLOCK_SIZE < 8);
if (!static_branch_likely(&blake2s_use_ssse3) || !crypto_simd_usable()) { blake2s_compress_generic(state, block, nblocks, inc); return; }
- for (;;) { + do { const size_t blocks = min_t(size_t, nblocks, - PAGE_SIZE / BLAKE2S_BLOCK_SIZE); + SZ_4K / BLAKE2S_BLOCK_SIZE);
kernel_fpu_begin(); if (IS_ENABLED(CONFIG_AS_AVX512) && @@ -52,10 +52,8 @@ void blake2s_compress_arch(struct blake2s_state *state, kernel_fpu_end();
nblocks -= blocks; - if (!nblocks) - break; block += blocks * BLAKE2S_BLOCK_SIZE; - } + } while (nblocks); } EXPORT_SYMBOL(blake2s_compress_arch);
diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c index b412c21ee06e..22250091cdbe 100644 --- a/arch/x86/crypto/chacha_glue.c +++ b/arch/x86/crypto/chacha_glue.c @@ -153,9 +153,17 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, bytes <= CHACHA_BLOCK_SIZE) return chacha_crypt_generic(state, dst, src, bytes, nrounds);
- kernel_fpu_begin(); - chacha_dosimd(state, dst, src, bytes, nrounds); - kernel_fpu_end(); + do { + unsigned int todo = min_t(unsigned int, bytes, SZ_4K); + + kernel_fpu_begin(); + chacha_dosimd(state, dst, src, todo, nrounds); + kernel_fpu_end(); + + bytes -= todo; + src += todo; + dst += todo; + } while (bytes); } EXPORT_SYMBOL(chacha_crypt_arch);
diff --git a/arch/x86/crypto/nhpoly1305-avx2-glue.c b/arch/x86/crypto/nhpoly1305-avx2-glue.c index f7567cbd35b6..80fcb85736e1 100644 --- a/arch/x86/crypto/nhpoly1305-avx2-glue.c +++ b/arch/x86/crypto/nhpoly1305-avx2-glue.c @@ -29,7 +29,7 @@ static int nhpoly1305_avx2_update(struct shash_desc *desc, return crypto_nhpoly1305_update(desc, src, srclen);
do { - unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE); + unsigned int n = min_t(unsigned int, srclen, SZ_4K);
kernel_fpu_begin(); crypto_nhpoly1305_update_helper(desc, src, n, _nh_avx2); diff --git a/arch/x86/crypto/nhpoly1305-sse2-glue.c b/arch/x86/crypto/nhpoly1305-sse2-glue.c index a661ede3b5cf..cc6b7c1a2705 100644 --- a/arch/x86/crypto/nhpoly1305-sse2-glue.c +++ b/arch/x86/crypto/nhpoly1305-sse2-glue.c @@ -29,7 +29,7 @@ static int nhpoly1305_sse2_update(struct shash_desc *desc, return crypto_nhpoly1305_update(desc, src, srclen);
do { - unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE); + unsigned int n = min_t(unsigned int, srclen, SZ_4K);
kernel_fpu_begin(); crypto_nhpoly1305_update_helper(desc, src, n, _nh_sse2); diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c index 6dfec19f7d57..dfe921efa9b2 100644 --- a/arch/x86/crypto/poly1305_glue.c +++ b/arch/x86/crypto/poly1305_glue.c @@ -91,8 +91,8 @@ static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len, struct poly1305_arch_internal *state = ctx;
/* SIMD disables preemption, so relax after processing each page. */ - BUILD_BUG_ON(PAGE_SIZE < POLY1305_BLOCK_SIZE || - PAGE_SIZE % POLY1305_BLOCK_SIZE); + BUILD_BUG_ON(SZ_4K < POLY1305_BLOCK_SIZE || + SZ_4K % POLY1305_BLOCK_SIZE);
if (!static_branch_likely(&poly1305_use_avx) || (len < (POLY1305_BLOCK_SIZE * 18) && !state->is_base2_26) || @@ -102,8 +102,8 @@ static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len, return; }
- for (;;) { - const size_t bytes = min_t(size_t, len, PAGE_SIZE); + do { + const size_t bytes = min_t(size_t, len, SZ_4K);
kernel_fpu_begin(); if (IS_ENABLED(CONFIG_AS_AVX512) && static_branch_likely(&poly1305_use_avx512)) @@ -113,11 +113,10 @@ static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len, else poly1305_blocks_avx(ctx, inp, bytes, padbit); kernel_fpu_end(); + len -= bytes; - if (!len) - break; inp += bytes; - } + } while (len); }
static void poly1305_simd_emit(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],