[PATCH v2] vhost: fix compilation issue in async path
Maxime Coquelin
maxime.coquelin at redhat.com
Wed Oct 5 17:11:59 CEST 2022
This patch fixes a compilation issue met with GCC 12 on
LoongArch64:
In function ‘mbuf_to_desc’,
inlined from ‘vhost_enqueue_async_packed’ at ../../../dpdk/lib/vhost/virtio_net.c:1822:6,
inlined from ‘virtio_dev_rx_async_packed’ at ../../../dpdk/lib/vhost/virtio_net.c:1836:6,
inlined from ‘virtio_dev_rx_async_submit_packed’ at ../../../dpdk/lib/vhost/virtio_net.c:1895:7:
../../../dpdk/lib/vhost/virtio_net.c:1159:18: error: ‘buf_vec[0].buf_addr’ may be used uninitialized [-Werror=maybe-uninitialized]
1159 | buf_addr = buf_vec[vec_idx].buf_addr;
| ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../dpdk/lib/vhost/virtio_net.c: In function ‘virtio_dev_rx_async_submit_packed’:
../../../dpdk/lib/vhost/virtio_net.c:1834:27: note: ‘buf_vec’ declared here
1834 | struct buf_vector buf_vec[BUF_VECTOR_MAX];
| ^~~~~~~
It happens because the compiler assumes that 'size'
variable in vhost_enqueue_async_packed could wrap to 0 since
'size' is uint32_t and pkt->pkt_len too.
In practice, it would never happen since 'pkt->pkt_len' is
unlikely to be close to UINT32_MAX, but let's just change
'size' to uint64_t to make the compiler happy without
having to add runtime checks.
Fixes: 873e8dad6f49 ("vhost: support packed ring in async datapath")
Cc: stable at dpdk.org
Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
lib/vhost/virtio_net.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index 8f4d0f0502..b86fb26040 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -1780,7 +1780,7 @@ vhost_enqueue_async_packed(struct virtio_net *dev,
uint16_t buf_id = 0;
uint32_t len = 0;
uint16_t desc_count = 0;
- uint32_t size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf);
+ uint64_t size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf);
uint32_t buffer_len[vq->size];
uint16_t buffer_buf_id[vq->size];
uint16_t buffer_desc_count[vq->size];
--
2.37.3
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