diff options
| author | Eric Biggers <ebiggers@kernel.org> | 2025-11-02 15:42:08 -0800 |
|---|---|---|
| committer | Eric Biggers <ebiggers@kernel.org> | 2025-11-05 20:30:52 -0800 |
| commit | cd5528621abb01664a477392cd3e76be2ef6296b (patch) | |
| tree | ecbb13c1f67c44fecfa557cbeff758e961b2e6af /lib | |
| parent | a7acd77ebd7f17b07a6ab2ca1dd1e4d487bdfa80 (diff) | |
lib/crypto: x86/blake2s: Avoid writing back unchanged 'f' value
Just before returning, blake2s_compress_ssse3() and
blake2s_compress_avx512() store updated values to the 'h', 't', and 'f'
fields of struct blake2s_ctx. But 'f' is always unchanged (which is
correct; only the C code changes it). So, there's no need to write to
'f'. Use 64-bit stores (movq and vmovq) instead of 128-bit stores
(movdqu and vmovdqu) so that only 't' is written.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20251102234209.62133-6-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/crypto/x86/blake2s-core.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/crypto/x86/blake2s-core.S b/lib/crypto/x86/blake2s-core.S index f805a49c590d..869064f6ac16 100644 --- a/lib/crypto/x86/blake2s-core.S +++ b/lib/crypto/x86/blake2s-core.S @@ -193,7 +193,7 @@ SYM_FUNC_START(blake2s_compress_ssse3) movdqu %xmm0,(CTX) // Store new h[0..3] movdqu %xmm1,16(CTX) // Store new h[4..7] - movdqu %xmm14,32(CTX) // Store new t and f + movq %xmm14,32(CTX) // Store new t (f is unchanged) RET SYM_FUNC_END(blake2s_compress_ssse3) @@ -287,7 +287,7 @@ SYM_FUNC_START(blake2s_compress_avx512) vmovdqu %xmm0,(CTX) // Store new h[0..3] vmovdqu %xmm1,16(CTX) // Store new h[4..7] - vmovdqu %xmm4,32(CTX) // Store new t and f + vmovq %xmm4,32(CTX) // Store new t (f is unchanged) vzeroupper RET SYM_FUNC_END(blake2s_compress_avx512) |