From 62fecf295e3c48be1b5f17c440b93875b9adb4d6 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sun, 27 Jan 2019 10:16:52 +0100 Subject: crypto: arm/crct10dif - revert to C code for short inputs The SIMD routine ported from x86 used to have a special code path for inputs < 16 bytes, which got lost somewhere along the way. Instead, the current glue code aligns the input pointer to permit the NEON routine to use special versions of the vld1 instructions that assume 16 byte alignment, but this could result in inputs of less than 16 bytes to be passed in. This not only fails the new extended tests that Eric has implemented, it also results in the code reading past the end of the input, which could potentially result in crashes when dealing with less than 16 bytes of input at the end of a page which is followed by an unmapped page. So update the glue code to only invoke the NEON routine if the input is at least 16 bytes. Reported-by: Eric Biggers Reviewed-by: Eric Biggers Fixes: 1d481f1cd892 ("crypto: arm/crct10dif - port x86 SSE implementation to ARM") Cc: # v4.10+ Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- arch/arm/crypto/crct10dif-ce-glue.c | 23 ++++++----------------- 1 file changed, 6 insertions(+), 17 deletions(-) (limited to 'arch/arm/crypto/crct10dif-ce-glue.c') diff --git a/arch/arm/crypto/crct10dif-ce-glue.c b/arch/arm/crypto/crct10dif-ce-glue.c index d428355cf38d..14c19c70a841 100644 --- a/arch/arm/crypto/crct10dif-ce-glue.c +++ b/arch/arm/crypto/crct10dif-ce-glue.c @@ -35,26 +35,15 @@ static int crct10dif_update(struct shash_desc *desc, const u8 *data, unsigned int length) { u16 *crc = shash_desc_ctx(desc); - unsigned int l; - if (!may_use_simd()) { - *crc = crc_t10dif_generic(*crc, data, length); + if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && may_use_simd()) { + kernel_neon_begin(); + *crc = crc_t10dif_pmull(*crc, data, length); + kernel_neon_end(); } else { - if (unlikely((u32)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) { - l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE - - ((u32)data % CRC_T10DIF_PMULL_CHUNK_SIZE)); - - *crc = crc_t10dif_generic(*crc, data, l); - - length -= l; - data += l; - } - if (length > 0) { - kernel_neon_begin(); - *crc = crc_t10dif_pmull(*crc, data, length); - kernel_neon_end(); - } + *crc = crc_t10dif_generic(*crc, data, length); } + return 0; } -- cgit v1.2.3