netdev - Re: [PATCH] net/tg3: resolve deadlock in tg3_reset

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CALs4sv3kA96-bfgR5VW967cKsW6z2Q1Y=ZMMomQDNT5_7jSWeg@mail.gmail.com>
Date:   Tue, 24 Jan 2023 14:42:35 +0530
From:   Pavan Chebbi <pavan.chebbi@...adcom.com>
To:     Michael Chan <michael.chan@...adcom.com>
Cc:     David Christensen <drc@...ux.vnet.ibm.com>, netdev@...r.kernel.org,
        Siva Reddy Kallam <siva.kallam@...adcom.com>,
        Prashant Sreedharan <prashant@...adcom.com>,
        Michael Chan <mchan@...adcom.com>
Subject: Re: [PATCH] net/tg3: resolve deadlock in tg3_reset_task() during EEH

On Tue, Jan 24, 2023 at 2:13 PM Michael Chan <michael.chan@...adcom.com> wrote:
>
> On Mon, Jan 23, 2023 at 11:25 PM Pavan Chebbi <pavan.chebbi@...adcom.com> wrote:
> >
> > On Tue, Jan 24, 2023 at 6:01 AM David Christensen
> > <drc@...ux.vnet.ibm.com> wrote:
> > >
> > >
> > > diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
> > > index 59debdc344a5..ee4604e6900e 100644
> > > --- a/drivers/net/ethernet/broadcom/tg3.c
> > > +++ b/drivers/net/ethernet/broadcom/tg3.c
> > > @@ -11166,7 +11166,8 @@ static void tg3_reset_task(struct work_struct *work)
> > >         rtnl_lock();
> > >         tg3_full_lock(tp, 0);
> > >
> > > -       if (!netif_running(tp->dev)) {
> > > +       // Skip reset task if no netdev or already in PCI recovery
> > > +       if (!tp->dev || tp->pcierr_recovery || !netif_running(tp->dev)) {
> >
> > Thanks for the patch. Can we not use netif_device_present() here?
>
> Take a look at the beginning of tg3_io_error_detected().  I think he
> is trying to follow the same recipe there.  Basically, if a PCIe AER
> has already been detected, then let it finish and do nothing here.
>

Agree. Just that tg3_io_error_detected() will have done a
netif_device_detach() earlier, I thought it may be a simpler check.
Fine with this as well. The submitter may choose to re-spin to remove
the tp->dev check otherwise looks good to me.
Reviewed-by: Pavan Chebbi <pavan.chebbi@...adcom.com>

> I don't think the tp->dev check is needed though.  We always call
> tg3_reset_task_cancel() before we call unregister_netdev() and
> free_netdev().
>
> >
> > >                 tg3_flag_clear(tp, RESET_TASK_PENDING);
> > >                 tg3_full_unlock(tp);
> > >                 rtnl_unlock();
> > > @@ -18101,6 +18102,9 @@ static pci_ers_result_t tg3_io_error_detected(struct pci_dev *pdev,
> > >
> > >         netdev_info(netdev, "PCI I/O error detected\n");
> > >
> > > +       /* Want to make sure that the reset task doesn't run */
> > > +       tg3_reset_task_cancel(tp);
> > > +
> > >         rtnl_lock();
> > >
> > >         /* Could be second call or maybe we don't have netdev yet */
> > > @@ -18117,9 +18121,6 @@ static pci_ers_result_t tg3_io_error_detected(struct pci_dev *pdev,
> > >
> > >         tg3_timer_stop(tp);
> > >
> > > -       /* Want to make sure that the reset task doesn't run */
> > > -       tg3_reset_task_cancel(tp);
> > > -
> > >         netif_device_detach(netdev);
> > >
> > >         /* Clean up software state, even if MMIO is blocked */
> > > --
> > > 2.31.1
> > >

Download attachment "smime.p7s" of type "application/pkcs7-signature" (4209 bytes)