Hi, On 5/9/23 11:35, Vadim Pasternak wrote: > > >> -----Original Message----- >> From: Liming Sun <limings@xxxxxxxxxx> >> Sent: Wednesday, 26 April 2023 17:24 >> To: Vadim Pasternak <vadimp@xxxxxxxxxx>; David Thompson >> <davthompson@xxxxxxxxxx>; Hans de Goede <hdegoede@xxxxxxxxxx>; >> Mark Gross <markgross@xxxxxxxxxx> >> Cc: Liming Sun <limings@xxxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx; >> linux-kernel@xxxxxxxxxxxxxxx >> Subject: [PATCH v1 1/1] platform/mellanox: fix potential race in mlxbf-tmfifo >> driver >> >> This commit adds memory barrier for the 'vq' update in function >> mlxbf_tmfifo_virtio_find_vqs() to avoid potential race due to out-of-order >> memory write. It also adds barrier for the 'is_ready' >> flag to make sure the initializations are visible before this flag is checked. >> >> Signed-off-by: Liming Sun <limings@xxxxxxxxxx> > > Reviewed-by: Vadim Pasternak <vadimp@xxxxxxxxxx> Thank you for your patch, I've applied this patch to my fixes branch: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=fixes Note it will show up in my fixes branch once I've pushed my local branch there, which might take a while. I will include this patch in my next fixes pull-req to Linus for the current kernel development cycle. Regards, Hans >> --- >> drivers/platform/mellanox/mlxbf-tmfifo.c | 11 +++++++++-- >> 1 file changed, 9 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/platform/mellanox/mlxbf-tmfifo.c >> b/drivers/platform/mellanox/mlxbf-tmfifo.c >> index 91a077c35b8b..a79318e90a13 100644 >> --- a/drivers/platform/mellanox/mlxbf-tmfifo.c >> +++ b/drivers/platform/mellanox/mlxbf-tmfifo.c >> @@ -784,7 +784,7 @@ static void mlxbf_tmfifo_rxtx(struct >> mlxbf_tmfifo_vring *vring, bool is_rx) >> fifo = vring->fifo; >> >> /* Return if vdev is not ready. */ >> - if (!fifo->vdev[devid]) >> + if (!fifo || !fifo->vdev[devid]) >> return; >> >> /* Return if another vring is running. */ @@ -980,9 +980,13 @@ >> static int mlxbf_tmfifo_virtio_find_vqs(struct virtio_device *vdev, >> >> vq->num_max = vring->num; >> >> + vq->priv = vring; >> + >> + /* Make vq update visible before using it. */ >> + virtio_mb(false); >> + >> vqs[i] = vq; >> vring->vq = vq; >> - vq->priv = vring; >> } >> >> return 0; >> @@ -1302,6 +1306,9 @@ static int mlxbf_tmfifo_probe(struct >> platform_device *pdev) >> >> mod_timer(&fifo->timer, jiffies + MLXBF_TMFIFO_TIMER_INTERVAL); >> >> + /* Make all updates visible before setting the 'is_ready' flag. */ >> + virtio_mb(false); >> + >> fifo->is_ready = true; >> return 0; >> >> -- >> 2.30.1 >
