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From:   Michael Kelley <mikelley@microsoft.com>
To:     "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>,
        KY Srinivasan <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>
CC:     "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 5/8] Drivers: hv: vmbus: Use channel_mutex in
 channel_vp_mapping_show()
Thread-Topic: [PATCH 5/8] Drivers: hv: vmbus: Use channel_mutex in
 channel_vp_mapping_show()
Thread-Index: AQHWRMcQpYkZTtgfg0etCx877itD1ajes3Iw
Date:   Thu, 18 Jun 2020 18:31:13 +0000
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References: <20200617164642.37393-1-parri.andrea@gmail.com>
 <20200617164642.37393-6-parri.andrea@gmail.com>
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From: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Sent: Wednesday, Ju=
ne 17, 2020 9:47 AM
>=20
> The primitive currently uses channel->lock to protect the loop over
> sc_list w.r.t. list additions/deletions but it doesn't protect the
> target_cpu(s) loads w.r.t. a concurrent target_cpu_store(): while the
> data races on target_cpu are hardly of any concern here, replace the
> channel->lock critical section with a channel_mutex critical section
> and extend the latter to include the loads of target_cpu; this same
> pattern is also used in hv_synic_cleanup().
>=20
> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
> ---
>  drivers/hv/vmbus_drv.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)

Reviewed-By: Michael Kelley <mikelley@microsoft.com>