Re: [PATCH v2] lib/ethdev: fix segfault in secondary process by validating dev_private pointer

[Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>]

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Thanks, no.
Can, I ?

On Wed, Jul 23, 2025, 18:24 Ivan Malov <ivan.malov@arknetworks.am> wrote:

> Hi Khadem,
>
> On Wed, 23 Jul 2025, Khadem Ullah wrote:
>
> > Please check v3 of this patch.
>
> Checked. In the meantime, you're not overlooking to mark previous versions
> [1]
> with status 'SUPERSEDED' in DPDK Patchwork, are you?
>
> [1]
> https://patches.dpdk.org/project/dpdk/patch/20250723045022.1580829-1-14pwcse1224@uetpeshawar.edu.pk/
>
> >
> > On Wed, Jul 23, 2025 at 5:19 PM Khadem Ullah <
> 14pwcse1224@uetpeshawar.edu.pk> wrote:
> >
> > Secondary application not only breaking on device closing,
> > it's also getting segfault when we do "show device info all" from
> secondary
> > after primary closes:
> > testpmd> show device info all
> > ********************* Infos for device 0000:03:00.0 *********************
> > Bus name: pci
> > Bus information: vendor_id=15b3, device_id=101d
> > Driver name: mlx5_pci
> > Devargs:
> > Connect to socket: 0
> > Segmentation fault (core dumped)
> > This patch prevents these crashes and it seems that these fixes should
> be in PMD along with the ethdev layer. Some more checks will be added in
> the next version to prevent "show device i
> > nfo all" crash.
> >
> >
> > On Wed, Jul 23, 2025 at 9:50 AM Khadem Ullah <
> 14pwcse1224@uetpeshawar.edu.pk> wrote:
> >       In secondary processes, directly accessing
> 'dev->data->dev_private' can
> >       cause a segmentation fault if the primary process has exited or if
> the
> >       shared memory is no longer accessible.
> >
> >       This patch adds a safety check using rte_mem_virt2phy(), with an
> >       unlikely() branch hint to minimize performance impact in the fast
> path.
> >       This ensures 'dev_private' is still valid before accessing it.
> >
> >       Fixes: bdad90d12ec8 ("ethdev: change device info get callback to
> return int")
> >       Cc: stable@dpdk.org
> >
> >       Signed-off-by: Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>
> >       ---
> >        lib/ethdev/rte_ethdev.c | 7 +++++++
> >        1 file changed, 7 insertions(+)
> >
> >       diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> >       index dd7c00bc94..ef5dc55f2e 100644
> >       --- a/lib/ethdev/rte_ethdev.c
> >       +++ b/lib/ethdev/rte_ethdev.c
> >       @@ -4079,6 +4079,13 @@ rte_eth_dev_info_get(uint16_t port_id,
> struct rte_eth_dev_info *dev_info)
> >
> >               if (dev->dev_ops->dev_infos_get == NULL)
> >                       return -ENOTSUP;
> >       +       if (rte_eal_process_type() == RTE_PROC_SECONDARY &&
> >       +               unlikely(rte_mem_virt2phy(dev->data->dev_private)
> == RTE_BAD_PHYS_ADDR)) {
> >       +                       RTE_ETHDEV_LOG_LINE(ERR,
> >       +                       "Secondary: dev_private not accessible
> (primary exited?)");
> >       +                       rte_errno = ENODEV;
> >       +                       return -rte_errno;
> >       +       }
> >               diag = dev->dev_ops->dev_infos_get(dev, dev_info);
> >               if (diag != 0) {
> >                       /* Cleanup already filled in device information */
> >       --
> >       2.43.0
> >
> >
> >
> > --
> > Engr. Khadem Ullah,
> > Software Engineer,
> > Dreambig Semiconductor Inc
> > https://dreambigsemi.com/
> >
> >
> >
> > --
> > Engr. Khadem Ullah,
> > Software Engineer,
> > Dreambig Semiconductor Inc
> > https://dreambigsemi.com/
> >
> >

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