From 832fe89013bc92dec7d17fcf5d6633c156371015 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Tue, 28 Jun 2016 13:31:21 -0700 Subject: [PATCH] Vectorized fletcher_4 must be 64-bit aligned The fletcher_4_native() and fletcher_4_byteswap() functions may only safely use the vectorized implementations when the buffer is 128-bit aligned. This is because both the AVX2 and SSE implementations process four 32-bit words per iterations. Fallback to the scalar implementation which only processes a single 32-bit word for unaligned buffers. Signed-off-by: Brian Behlendorf Issue #4330 --- module/zcommon/zfs_fletcher.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/module/zcommon/zfs_fletcher.c b/module/zcommon/zfs_fletcher.c index 2c2d01d5c2c5..e76c5b8a5835 100644 --- a/module/zcommon/zfs_fletcher.c +++ b/module/zcommon/zfs_fletcher.c @@ -334,7 +334,12 @@ fletcher_4_impl_get(void) void fletcher_4_native(const void *buf, uint64_t size, zio_cksum_t *zcp) { - const fletcher_4_ops_t *ops = fletcher_4_impl_get(); + const fletcher_4_ops_t *ops; + + if (IS_P2ALIGNED(size, 4 * sizeof (uint32_t))) + ops = fletcher_4_impl_get(); + else + ops = &fletcher_4_scalar_ops; ops->init(zcp); ops->compute(buf, size, zcp); @@ -345,7 +350,12 @@ fletcher_4_native(const void *buf, uint64_t size, zio_cksum_t *zcp) void fletcher_4_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp) { - const fletcher_4_ops_t *ops = fletcher_4_impl_get(); + const fletcher_4_ops_t *ops; + + if (IS_P2ALIGNED(size, 4 * sizeof (uint32_t))) + ops = fletcher_4_impl_get(); + else + ops = &fletcher_4_scalar_ops; ops->init(zcp); ops->compute_byteswap(buf, size, zcp);