[PATCH v3] hash: fix pointer alignment

[Radu Nicolau]

rte_hash_crc assumes input pointer address is 8 byte aligned
which may not be always the case.
This fix aligns the input pointer before proceeding to process it
in 8 byte chunks.

Bugzilla ID: 1892
Fixes: 504a29af13a7 ("hash: fix strict-aliasing for CRC")
Cc: stable at dpdk.org
Cc: stephen at networkplumber.org

Signed-off-by: Radu Nicolau <radu.nicolau at intel.com>
Acked-by: Marat Khalili <marat.khalili at huawei.com>
---
v3: revert alignment code to simple loop, it was getting too complex for a corner case


 lib/hash/rte_hash_crc.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/hash/rte_hash_crc.h b/lib/hash/rte_hash_crc.h
index fa07c97685..f60f4598d8 100644
--- a/lib/hash/rte_hash_crc.h
+++ b/lib/hash/rte_hash_crc.h
@@ -127,6 +127,16 @@ rte_hash_crc(const void *data, uint32_t data_len, uint32_t init_val)
 	unsigned i;
 	uintptr_t pd = (uintptr_t) data;
 
+	/* align input to 8 byte boundary if needed */
+	if (pd & 0x7) {
+		unsigned int unaligned_bytes = RTE_MIN(8 - (pd & 0x7), data_len);
+		for (i = 0; i < unaligned_bytes; i++) {
+			init_val = rte_hash_crc_1byte(*(const uint8_t *)pd, init_val);
+			pd++;
+			data_len--;
+		}
+	}
+
 	for (i = 0; i < data_len / 8; i++) {
 		init_val = rte_hash_crc_8byte(*(const uint64_t *)pd, init_val);
 		pd += 8;
-- 
2.52.0