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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/arm64
parent55b3209acbb01cb02b1ee6b1afe80d83b1aab36d (diff)
downloadlinux-706024a52c614b478b63f7728d202532ce6591a9.tar.bz2
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/arm64')
-rw-r--r--arch/arm64/crypto/chacha-neon-glue.c14
-rw-r--r--arch/arm64/crypto/poly1305-glue.c15
2 files changed, 22 insertions, 7 deletions
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/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;
}