From: Ruifeng Wang <Ruifeng.Wang@arm.com>
To: Amit Prakash Shukla <amitprakashs@marvell.com>,
Maxime Coquelin <maxime.coquelin@redhat.com>,
Chenbo Xia <chenbo.xia@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"jerinj@marvell.com" <jerinj@marvell.com>,
"stable@dpdk.org" <stable@dpdk.org>, nd <nd@arm.com>
Subject: RE: [PATCH] vhost: compilation fix for GCC-12
Date: Fri, 2 Sep 2022 07:23:39 +0000 [thread overview]
Message-ID: <AS8PR08MB7080E0056C9826A40F7E1EFC9E7A9@AS8PR08MB7080.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <20220901084943.3075710-1-amitprakashs@marvell.com>
> -----Original Message-----
> From: Amit Prakash Shukla <amitprakashs@marvell.com>
> Sent: Thursday, September 1, 2022 4:50 PM
> To: Maxime Coquelin <maxime.coquelin@redhat.com>; Chenbo Xia <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; jerinj@marvell.com; stable@dpdk.org; Amit Prakash Shukla
> <amitprakashs@marvell.com>
> Subject: [PATCH] vhost: compilation fix for GCC-12
>
> ../lib/vhost/virtio_net.c:941:35: error:
> 'buf_vec[0].buf_len' may be used uninitialized
> [-Werror=maybe-uninitialized]
> 941 | buf_len = buf_vec[vec_idx].buf_len;
> | ~~~~~~~~~~~~~~~~^~~~~~~~
> ../lib/vhost/virtio_net.c: In function 'virtio_dev_rx_packed':
> ../lib/vhost/virtio_net.c:1285:27: note: 'buf_vec' declared here
> 1285 | struct buf_vector buf_vec[BUF_VECTOR_MAX];
> | ^~~~~~~
> cc1: all warnings being treated as errors
>
> Fixes: 93520085efda ("vhost: add packed ring single enqueue")
> Cc: stable@dpdk.org
>
> Signed-off-by: Amit Prakash Shukla <amitprakashs@marvell.com>
> ---
> lib/vhost/virtio_net.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index b3d954aab4..0220bc923c
> 100644
> --- a/lib/vhost/virtio_net.c
> +++ b/lib/vhost/virtio_net.c
> @@ -1069,6 +1069,12 @@ vhost_enqueue_single_packed(struct virtio_net *dev,
> else
> max_tries = 1;
>
> + /* To avoid GCC-12 warning.
> + * GCC-12 is not evaluating sizeof at compile time.
Is this a compiler behavior change against previous versions?
I tried to find some clue from gcc-12 doc but got nothing. Can you point me to any material?
> + */
> + if (unlikely(size == 0))
> + return -1;
> +
> while (size > 0) {
Change 'while(){}' to 'do{}while()' can be a simpler solution. What do you think?
Thanks.
> /*
> * if we tried all available ring items, and still @@ -1574,6 +1580,12 @@
> vhost_enqueue_async_packed(struct virtio_net *dev,
> else
> max_tries = 1;
>
> + /* To avoid GCC-12 warning.
> + * GCC-12 is not evaluating sizeof at compile time.
> + */
> + if (unlikely(size == 0))
> + return -1;
> +
> while (size > 0) {
> /*
> * if we tried all available ring items, and still
> --
> 2.25.1
next prev parent reply other threads:[~2022-09-02 7:23 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 8:49 Amit Prakash Shukla
2022-09-02 7:23 ` Ruifeng Wang [this message]
2022-09-02 11:57 ` Amit Prakash Shukla
2022-09-02 12:41 ` [PATCH v2] " Amit Prakash Shukla
2022-09-02 12:56 ` Bagas Sanjaya
2022-09-02 15:11 ` [EXT] " Amit Prakash Shukla
2022-09-02 15:06 ` [PATCH v3] " Amit Prakash Shukla
2022-10-06 7:22 ` Amit Prakash Shukla
2022-10-06 7:24 ` Maxime Coquelin
2022-10-06 8:05 ` [EXT] " Amit Prakash Shukla
2022-10-06 12:35 ` David Marchand
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