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 more than 16 bytes.
Reported-by: Eric Biggers ebiggers@kernel.org Fixes: 1d481f1cd892 ("crypto: arm/crct10dif - port x86 SSE implementation to ARM") Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org --- arch/arm/crypto/crct10dif-ce-core.S | 14 ++++++------ arch/arm/crypto/crct10dif-ce-glue.c | 23 +++++--------------- 2 files changed, 13 insertions(+), 24 deletions(-)
diff --git a/arch/arm/crypto/crct10dif-ce-core.S b/arch/arm/crypto/crct10dif-ce-core.S index ce45ba0c0687..16019b5961e7 100644 --- a/arch/arm/crypto/crct10dif-ce-core.S +++ b/arch/arm/crypto/crct10dif-ce-core.S @@ -124,10 +124,10 @@ ENTRY(crc_t10dif_pmull) vext.8 q10, qzr, q0, #4
// receive the initial 64B data, xor the initial crc value - vld1.64 {q0-q1}, [arg2, :128]! - vld1.64 {q2-q3}, [arg2, :128]! - vld1.64 {q4-q5}, [arg2, :128]! - vld1.64 {q6-q7}, [arg2, :128]! + vld1.64 {q0-q1}, [arg2]! + vld1.64 {q2-q3}, [arg2]! + vld1.64 {q4-q5}, [arg2]! + vld1.64 {q6-q7}, [arg2]! CPU_LE( vrev64.8 q0, q0 ) CPU_LE( vrev64.8 q1, q1 ) CPU_LE( vrev64.8 q2, q2 ) @@ -167,7 +167,7 @@ CPU_LE( vrev64.8 q7, q7 ) _fold_64_B_loop:
.macro fold64, reg1, reg2 - vld1.64 {q11-q12}, [arg2, :128]! + vld1.64 {q11-q12}, [arg2]!
vmull.p64 q8, \reg1()h, d21 vmull.p64 \reg1, \reg1()l, d20 @@ -238,7 +238,7 @@ _16B_reduction_loop: vmull.p64 q7, d15, d21 veor.8 q7, q7, q8
- vld1.64 {q0}, [arg2, :128]! + vld1.64 {q0}, [arg2]! CPU_LE( vrev64.8 q0, q0 ) vswp d0, d1 veor.8 q7, q7, q0 @@ -335,7 +335,7 @@ _less_than_128: vmov.i8 q0, #0 vmov s3, arg1_low32 // get the initial crc value
- vld1.64 {q7}, [arg2, :128]! + vld1.64 {q7}, [arg2]! CPU_LE( vrev64.8 q7, q7 ) vswp d14, d15 veor.8 q7, q7, q0 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; }