From: Ferruh Yigit <ferruh.yigit@amd.com>
To: Gagandeep Singh <G.Singh@nxp.com>, "dev@dpdk.org" <dev@dpdk.org>
Cc: "stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [PATCH 15/15] net/dpaa: fix buffer free in slow path
Date: Thu, 6 Oct 2022 10:42:29 +0100 [thread overview]
Message-ID: <3a635d69-ce9c-3240-ee3b-dccd6b3d0880@amd.com> (raw)
In-Reply-To: <AS8PR04MB8198E001E84B09DDF350190FE15C9@AS8PR04MB8198.eurprd04.prod.outlook.com>
On 10/6/2022 9:51 AM, Gagandeep Singh wrote:
> Hi,
>
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit@amd.com>
>> Sent: Wednesday, October 5, 2022 7:52 PM
>> To: Gagandeep Singh <G.Singh@nxp.com>; dev@dpdk.org
>> Cc: stable@dpdk.org
>> Subject: Re: [PATCH 15/15] net/dpaa: fix buffer free in slow path
>>
>> On 9/28/2022 6:25 AM, Gagandeep Singh wrote:
>>> Adding a check in slow path to free those buffers which are not
>>> external.
>>>
>>
>> Can you please explain what was the error before fix, what was happening
>> when you try to free all mbufs?
>>
>> Also it seems previous logic was different, with 'prev_seg' etc, can you
>> explain what/why changed there?
>>
> Actually, there were two issues, this function was converting all the segments present in HW frame
> descriptor to mbuf SG list by doing while on segments in FD (HW descriptor) and in the end
> it frees only one segment by calling the API rte_pktmbuf_free_seg(), so for other segments
> memory will be leaked.
>
ack
> Now in this change, doing the loop on each segment in FD and if the segment has a valid
> buffer pool id (HW pool id), freeing that segment in the loop itself without converting to a mbuf list.
> if we free all the buffers even those with invalid HW bpid (which will only be the external buffer case),
> then there can be double free because all the external buffer free handling is being done by the
> Xmit function.
>
Got it, can you please give more information in the commit log as above,
and can you please elaborate impact of possible double free, will it
crash etc?
>>> Fixes: 9124e65dd3eb ("net/dpaa: enable Tx queue taildrop")
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Gagandeep Singh <g.singh@nxp.com>
>>> ---
>>> drivers/net/dpaa/dpaa_rxtx.c | 23 ++++++++---------------
>>> 1 file changed, 8 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/drivers/net/dpaa/dpaa_rxtx.c
>>> b/drivers/net/dpaa/dpaa_rxtx.c index 4d285b4f38..ce4f3d6c85 100644
>>> --- a/drivers/net/dpaa/dpaa_rxtx.c
>>> +++ b/drivers/net/dpaa/dpaa_rxtx.c
>>> @@ -455,7 +455,7 @@ dpaa_free_mbuf(const struct qm_fd *fd)
>>> bp_info = DPAA_BPID_TO_POOL_INFO(fd->bpid);
>>> format = (fd->opaque & DPAA_FD_FORMAT_MASK) >>
>> DPAA_FD_FORMAT_SHIFT;
>>> if (unlikely(format == qm_fd_sg)) {
>>> - struct rte_mbuf *first_seg, *prev_seg, *cur_seg, *temp;
>>> + struct rte_mbuf *first_seg, *cur_seg;
>>> struct qm_sg_entry *sgt, *sg_temp;
>>> void *vaddr, *sg_vaddr;
>>> int i = 0;
>>> @@ -469,32 +469,25 @@ dpaa_free_mbuf(const struct qm_fd *fd)
>>> sgt = vaddr + fd_offset;
>>> sg_temp = &sgt[i++];
>>> hw_sg_to_cpu(sg_temp);
>>> - temp = (struct rte_mbuf *)
>>> - ((char *)vaddr - bp_info->meta_data_size);
>>> sg_vaddr = DPAA_MEMPOOL_PTOV(bp_info,
>>>
>> qm_sg_entry_get64(sg_temp));
>>> -
>>> first_seg = (struct rte_mbuf *)((char *)sg_vaddr -
>>> bp_info->meta_data_size);
>>> first_seg->nb_segs = 1;
>>> - prev_seg = first_seg;
>>> while (i < DPAA_SGT_MAX_ENTRIES) {
>>> sg_temp = &sgt[i++];
>>> hw_sg_to_cpu(sg_temp);
>>> - sg_vaddr = DPAA_MEMPOOL_PTOV(bp_info,
>>> + if (sg_temp->bpid != 0xFF) {
>>> + bp_info =
>> DPAA_BPID_TO_POOL_INFO(sg_temp->bpid);
>>> + sg_vaddr = DPAA_MEMPOOL_PTOV(bp_info,
>>>
>> qm_sg_entry_get64(sg_temp));
>>> - cur_seg = (struct rte_mbuf *)((char *)sg_vaddr -
>>> + cur_seg = (struct rte_mbuf *)((char
>> *)sg_vaddr -
>>> bp_info-
>>> meta_data_size);
>>> - first_seg->nb_segs += 1;
>>> - prev_seg->next = cur_seg;
>>> - if (sg_temp->final) {
>>> - cur_seg->next = NULL;
>>> - break;
>>> + rte_pktmbuf_free_seg(cur_seg);
>>> }
>>> - prev_seg = cur_seg;
>>> + if (sg_temp->final)
>>> + break;
>>> }
>>> -
>>> - rte_pktmbuf_free_seg(temp);
>>> rte_pktmbuf_free_seg(first_seg);
>>> return 0;
>>> }
>
next prev parent reply other threads:[~2022-10-06 9:42 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220928052516.1279442-1-g.singh@nxp.com>
2022-09-28 5:25 ` [PATCH 02/15] net/enetfec: fix restart issue Gagandeep Singh
2022-09-28 5:25 ` [PATCH 03/15] net/enetfec: fix buffer leak issue Gagandeep Singh
2022-09-28 5:25 ` [PATCH 04/15] net/dpaa2: fix dpdmux configuration for error behaviour Gagandeep Singh
2022-09-28 5:25 ` [PATCH 05/15] net/dpaa2: check free enqueue descriptors before Tx Gagandeep Singh
2022-10-05 14:30 ` Ferruh Yigit
2022-09-28 5:25 ` [PATCH 08/15] net/dpaa2: fix buffer free on transmit SG packets Gagandeep Singh
2022-10-06 7:48 ` Ferruh Yigit
2022-09-28 5:25 ` [PATCH 10/15] net/dpaa: fix Jumbo packet Rx in case of VSP Gagandeep Singh
2022-09-28 5:25 ` [PATCH 14/15] net/dpaa: fix buffer free on transmit SG packets Gagandeep Singh
2022-09-28 5:25 ` [PATCH 15/15] net/dpaa: fix buffer free in slow path Gagandeep Singh
2022-10-05 14:21 ` Ferruh Yigit
2022-10-06 8:51 ` Gagandeep Singh
2022-10-06 9:42 ` Ferruh Yigit [this message]
2022-10-06 11:19 ` Gagandeep Singh
[not found] ` <20221007032743.2129353-1-g.singh@nxp.com>
2022-10-07 3:27 ` [PATCH v2 02/16] net/enetfec: fix restart issue Gagandeep Singh
2022-10-07 3:27 ` [PATCH v2 03/16] net/enetfec: fix buffer leak issue Gagandeep Singh
2022-10-07 3:27 ` [PATCH v2 04/16] net/dpaa2: fix dpdmux configuration for error behaviour Gagandeep Singh
2022-10-07 3:27 ` [PATCH v2 05/16] net/dpaa2: check free enqueue descriptors before Tx Gagandeep Singh
2022-10-07 3:27 ` [PATCH v2 08/16] net/dpaa2: fix buffer free on transmit SG packets Gagandeep Singh
2022-10-07 3:27 ` [PATCH v2 10/16] net/dpaa: fix Jumbo packet Rx in case of VSP Gagandeep Singh
2022-10-07 3:27 ` [PATCH v2 15/16] net/dpaa: fix buffer free on transmit SG packets Gagandeep Singh
2022-10-07 3:27 ` [PATCH v2 16/16] net/dpaa: fix buffer free in slow path Gagandeep Singh
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