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crypto: arch/lib - limit simd usage to 4k chunks

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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 for the
former two).

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: 84e03fa39f ("crypto: x86/chacha - expose SIMD ChaCha routine as library function")
Fixes: b3aad5bad2 ("crypto: arm64/chacha - expose arm64 ChaCha routine as library function")
Fixes: a44a3430d7 ("crypto: arm/chacha - expose ARM ChaCha routine as library function")
Fixes: d7d7b85356 ("crypto: x86/poly1305 - wire up faster implementations for kernel")
Fixes: f569ca1647 ("crypto: arm64/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation")
Fixes: a6b803b3dd ("crypto: arm/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation")
Fixes: ed0356eda1 ("crypto: blake2s - x86_64 SIMD implementation")
Cc: Eric Biggers <ebiggers@google.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Jason A. Donenfeld 2020-04-22 17:18:53 -06:00 committed by Herbert Xu
parent 55b3209acb
commit 706024a52c
7 changed files with 65 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
arch/arm/crypto/chacha-glue.c
View File

@ -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);

15
arch/arm/crypto/poly1305-glue.c
View File

@ -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;
}

14
arch/arm64/crypto/chacha-neon-glue.c
View File

@ -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);

15
arch/arm64/crypto/poly1305-glue.c
View File

@ -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;
}

10
arch/x86/crypto/blake2s-glue.c
View File

@ -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);

14
arch/x86/crypto/chacha_glue.c
View File

@ -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);

13
arch/x86/crypto/poly1305_glue.c
View File

@ -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],