This is for target i686-native-linuxapp-gcc and gcc6,
Compilation error is:
== Build drivers/net/virtio
CC virtio_rxtx_simple.o
In file included from
.../build/include/rte_mempool.h:77:0,
from
.../drivers/net/virtio/virtio_rxtx_simple.c:46:
.../drivers/net/virtio/virtio_rxtx_simple.c: In
function ?virtio_xmit_pkts_simple?:
.../build/include/rte_memcpy.h:551:2: error: array
subscript is above array bounds [-Werror=array-bounds]
rte_mov16((uint8_t *)dst + 1 * 16, (const uint8_t *)src + 1 * 16);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Call stack is as following:
virtio_xmit_pkts_simple
virtio_xmit_cleanup
rte_mempool_put_bulk
rte_mempool_generic_put
__mempool_generic_put
rte_memcpy
The array used as source buffer in virtio_xmit_cleanup (free) is a
pointer array with 32 elements, in 32bit this makes 128 bytes.
in rte_memcpy() implementation, there a code piece as following:
if (size > 256) {
rte_move128(...);
rte_move128(...); <--- [1]
....
}
The compiler traces the array all through the call stack and knows the
size of array is 128 and generates a warning on above [1] which tries to
access beyond byte 128.
But unfortunately it ignores the "(size > 256)" check.
Giving a hint to compiler that variable "size" is related to the size of
the source buffer fixes compiler warning.
Fixes: 863bfb474493 ("mempool: optimize copy in cache")
Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
---
drivers/net/virtio/virtio_rxtx_simple.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/net/virtio/virtio_rxtx_simple.c
b/drivers/net/virtio/virtio_rxtx_simple.c
index 242ad90..d8fcc15 100644
--- a/drivers/net/virtio/virtio_rxtx_simple.c
+++ b/drivers/net/virtio/virtio_rxtx_simple.c
@@ -301,7 +301,7 @@ static inline void
virtio_xmit_cleanup(struct virtqueue *vq)
{
uint16_t i, desc_idx;
- int nb_free = 0;
+ uint32_t nb_free = 0;
struct rte_mbuf *m, *free[VIRTIO_TX_MAX_FREE_BUF_SZ];
desc_idx = (uint16_t)(vq->vq_used_cons_idx &
@@ -319,13 +319,16 @@ virtio_xmit_cleanup(struct virtqueue *vq)
free[nb_free++] = m;
else {
rte_mempool_put_bulk(free[0]->pool,
- (void **)free, nb_free);
+ (void **)free,
+ RTE_MIN(RTE_DIM(free),
+ nb_free));
free[0] = m;
nb_free = 1;
}
}
}
- rte_mempool_put_bulk(free[0]->pool, (void **)free, nb_free);
+ rte_mempool_put_bulk(free[0]->pool, (void **)free,
+ RTE_MIN(RTE_DIM(free), nb_free));
} else {
for (i = 1; i < VIRTIO_TX_FREE_NR; i++) {
m = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie;
--
2.7.4
