Hi Maxime, Sure, I will test and reply on your patch.
Thanks, Amit Shukla > -----Original Message----- > From: Maxime Coquelin <maxime.coque...@redhat.com> > Sent: Thursday, October 6, 2022 12:55 PM > To: Amit Prakash Shukla <amitpraka...@marvell.com>; Chenbo Xia > <chenbo....@intel.com> > Cc: dev@dpdk.org; Jerin Jacob Kollanukkaran <jer...@marvell.com>; > sta...@dpdk.org; ruifeng.w...@arm.com > Subject: [EXT] Re: [PATCH v3] vhost: compilation fix for GCC-12 > > External Email > > ---------------------------------------------------------------------- > Hi Amit, > > On 10/6/22 09:22, Amit Prakash Shukla wrote: > > Ping. > > I posted a patch yesterday that fixes this issue without having to change the > runtime behavior: > > https://urldefense.proofpoint.com/v2/url?u=http- > 3A__patches.dpdk.org_project_dpdk_patch_20221005203524.89336-2D1- > 2Dmaxime.coquelin- > 40redhat.com_&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=ALGdXl3fZgFG > R69VnJLdSnADun7zLaXG1p5Rs7pXihE&m=vDZyV- > pKSmtssm0L8YUPR6doPgIw44tOh3xWgNEwD3FGjqEomaP9lcYLhrbqwGKb&s > =g54ujCkU-mDT0CQoJgqYlDllGLuzWs8lLa6YMzPfqkw&e= > > Could you test it and provide ack if OK on your side? > > Thanks, > Maxime > > >> -----Original Message----- > >> From: Amit Prakash Shukla <amitpraka...@marvell.com> > >> Sent: Friday, September 2, 2022 8:36 PM > >> To: Maxime Coquelin <maxime.coque...@redhat.com>; Chenbo Xia > >> <chenbo....@intel.com> > >> Cc: dev@dpdk.org; Jerin Jacob Kollanukkaran <jer...@marvell.com>; > >> sta...@dpdk.org; ruifeng.w...@arm.com; Amit Prakash Shukla > >> <amitpraka...@marvell.com> > >> Subject: [PATCH v3] vhost: compilation fix for GCC-12 > >> > >> GCC-12 complains about the possible use of un-initialized array. At > >> compile time it seems like it is not able to evaluate the size as it > >> involves run-time variable and at compile time it seems like gcc > >> assumes value of "size" variable to be zero which makes gcc-12 to jump > the while loop. > >> "size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf);" > >> > >> As part of the fix, "while (){}" is replaced by "do {} while()" which > >> make the compiler to generate a code in which buf_vec will never be > >> used un- initialized. > >> > >> ../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: sta...@dpdk.org > >> > >> Signed-off-by: Amit Prakash Shukla <amitpraka...@marvell.com> > >> --- > >> v2: > >> - Changes for code review suggestion > >> > >> v3: > >> - Added a description > >> > >> lib/vhost/virtio_net.c | 8 ++++---- > >> 1 file changed, 4 insertions(+), 4 deletions(-) > >> > >> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index > >> b3d954aab4..9b77d3d10f 100644 > >> --- a/lib/vhost/virtio_net.c > >> +++ b/lib/vhost/virtio_net.c > >> @@ -1069,7 +1069,7 @@ vhost_enqueue_single_packed(struct virtio_net > >> *dev, > >> else > >> max_tries = 1; > >> > >> - while (size > 0) { > >> + do { > >> /* > >> * if we tried all available ring items, and still > >> * can't get enough buf, it means something abnormal @@ - > >> 1097,7 +1097,7 @@ vhost_enqueue_single_packed(struct virtio_net > *dev, > >> avail_idx += desc_count; > >> if (avail_idx >= vq->size) > >> avail_idx -= vq->size; > >> - } > >> + } while (size > 0); > >> > >> if (mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, num_buffers, > >> false) < 0) > >> return -1; > >> @@ -1574,7 +1574,7 @@ vhost_enqueue_async_packed(struct virtio_net > >> *dev, > >> else > >> max_tries = 1; > >> > >> - while (size > 0) { > >> + do { > >> /* > >> * if we tried all available ring items, and still > >> * can't get enough buf, it means something abnormal @@ - > >> 1601,7 +1601,7 @@ vhost_enqueue_async_packed(struct virtio_net > *dev, > >> avail_idx += desc_count; > >> if (avail_idx >= vq->size) > >> avail_idx -= vq->size; > >> - } > >> + } while (size > 0); > >> > >> if (unlikely(mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, > >> *nr_buffers, true) < 0)) > >> return -1; > >> -- > >> 2.25.1 > >
