patches for DPDK stable branches
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From: Thomas Monjalon <thomas@monjalon.net>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: dev@dpdk.org, cheng1.jiang@intel.com, chenbo.xia@intel.com,
	zhoumin@loongson.cn, david.marchand@redhat.com, stable@dpdk.org
Subject: Re: [PATCH v3] vhost: fix build issues with GCC 12
Date: Thu, 06 Oct 2022 12:21:34 +0200	[thread overview]
Message-ID: <3636953.MHq7AAxBmi@thomas> (raw)
In-Reply-To: <20221005203524.89336-1-maxime.coquelin@redhat.com>

05/10/2022 22:35, Maxime Coquelin:
> 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.
> 
> This patch also fixes similar patterns in three other
> places, including one that also produces similar build
> issue on ARM64 in vhost_enqueue_single_packed().
> 
> Fixes: 873e8dad6f49 ("vhost: support packed ring in async datapath")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Reviewed-by: David Marchand <david.marchand@redhat.com>
Tested-by: Amit Prakash Shukla <amitprakashs@marvell.com>

Applied, thanks.




      parent reply	other threads:[~2022-10-06 10:21 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-05 15:11 [PATCH v2] vhost: fix compilation issue in async path Maxime Coquelin
2022-10-05 15:36 ` Maxime Coquelin
2022-10-05 16:34   ` David Marchand
2022-10-05 20:35 ` [PATCH v3] vhost: fix build issues with GCC 12 Maxime Coquelin
2022-10-06  0:01   ` Stephen Hemminger
2022-10-06  7:51     ` Maxime Coquelin
2022-10-06  8:22       ` [EXT] " Amit Prakash Shukla
2022-10-06  9:05         ` Maxime Coquelin
2022-10-06 10:21   ` Thomas Monjalon [this message]

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