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authorJason A. Donenfeld <Jason@zx2c4.com>2020-04-22 17:18:53 -0600
committerHerbert Xu <herbert@gondor.apana.org.au>2020-04-30 15:16:59 +1000
commit706024a52c614b478b63f7728d202532ce6591a9 (patch)
tree0ed965bee44426700d70ca1d6ed40f2f26508684 /arch/x86/crypto
parent55b3209acbb01cb02b1ee6b1afe80d83b1aab36d (diff)
crypto: arch/lib - limit simd usage to 4k chunks
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: 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: ed0356eda153 ("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>
Diffstat (limited to 'arch/x86/crypto')
-rw-r--r--arch/x86/crypto/blake2s-glue.c10
-rw-r--r--arch/x86/crypto/chacha_glue.c14
-rw-r--r--arch/x86/crypto/poly1305_glue.c13
3 files changed, 21 insertions, 16 deletions
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/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],