linux-kernel - Re: [PATCH] Bluetooth: Clear suspend tasks on unregister

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] [day] [month] [year] [list]

Date:   Mon, 31 Aug 2020 09:51:56 -0700
From:   Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
To:     Marcel Holtmann <marcel@...tmann.org>
Cc:     linux-bluetooth <linux-bluetooth@...r.kernel.org>,
        CrosBT Upstreaming <chromeos-bluetooth-upstreaming@...omium.org>,
        "David S. Miller" <davem@...emloft.net>,
        Johan Hedberg <johan.hedberg@...il.com>,
        netdev <netdev@...r.kernel.org>,
        kernel list <linux-kernel@...r.kernel.org>,
        Jakub Kicinski <kuba@...nel.org>,
        Miao-chen Chou <mcchou@...omium.org>
Subject: Re: [PATCH] Bluetooth: Clear suspend tasks on unregister

v2 sent with fix.

On Mon, Aug 31, 2020 at 8:49 AM Marcel Holtmann <marcel@...tmann.org> wrote:
>
> Hi Abhishek,
>
> > While unregistering, make sure to clear the suspend tasks before
> > cancelling the work. If the unregister is called during resume from
> > suspend, this will unnecessarily add 2s to the resume time otherwise.
> >
> > Fixes: 4e8c36c3b0d73d (Bluetooth: Fix suspend notifier race)
> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
> > ---
> > This was discovered with RT8822CE using the btusb driver. This chipset
> > will reset on resume during system suspend and was unnecessarily adding
> > 2s to every resume. Since we're unregistering anyway, there's no harm in
> > just clearing the pending events.
> >
> > net/bluetooth/hci_core.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> > index 68bfe57b66250f..ed4cb3479433c0 100644
> > --- a/net/bluetooth/hci_core.c
> > +++ b/net/bluetooth/hci_core.c
> > @@ -3442,6 +3442,16 @@ void hci_copy_identity_address(struct hci_dev *hdev, bdaddr_t *bdaddr,
> >       }
> > }
> >
> > +static void hci_suspend_clear_tasks(struct hci_dev *hdev)
> > +{
> > +     int i;
> > +
> > +     for (i = 0; i < __SUSPEND_NUM_TASKS; ++i)
> > +             clear_bit(i, hdev->suspend_tasks);
>
> I prefer i++ instead of ++i.
>
> Regards
>
> Marcel
>