* Re: [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails
[not found] <1628029342-3638-1-git-send-email-rishabhb@codeaurora.org>
@ 2021-08-04 8:33 ` Cristian Marussi
2021-08-04 8:40 ` Cristian Marussi
0 siblings, 1 reply; 2+ messages in thread
From: Cristian Marussi @ 2021-08-04 8:33 UTC (permalink / raw)
To: Rishabh Bhatnagar
Cc: sudeep.holla, linux-arm-kernel, linux-kernel, avajid, adharmap
On Tue, Aug 03, 2021 at 03:22:22PM -0700, Rishabh Bhatnagar wrote:
> Mailbox channels for the base protocol are setup during probe.
> There can be a scenario where probe fails to acquire the base
> protocol due to a timeout leading to cleaning up of all device
> managed memory including the scmi_mailbox structure setup during
> mailbox_chan_setup function.
> [ 12.735104]arm-scmi soc:qcom,scmi: timed out in resp(caller: version_get+0x84/0x140)
> [ 12.735224]arm-scmi soc:qcom,scmi: unable to communicate with SCMI
> [ 12.735947]arm-scmi: probe of soc:qcom,scmi failed with error -110
>
> Now when a message arrives at cpu slightly after the timeout, the mailbox
> controller will try to call the rx_callback of the client and might end
> up accessing freed memory.
> [ 12.758363][ C0] Call trace:
> [ 12.758367][ C0] rx_callback+0x24/0x160
> [ 12.758372][ C0] mbox_chan_received_data+0x44/0x94
> [ 12.758386][ C0] __handle_irq_event_percpu+0xd4/0x240
> This patch frees the mailbox channels setup during probe and adds some more
> error handling in case the probe fails.
>
> Change-Id: I1214ec2c4c92c4a3ca5fa73de11e0e403b13b46a
> Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Hi Rishabh,
Good catch, thanks for this.
> ---
> drivers/firmware/arm_scmi/driver.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
> index 9b2e8d4..518c7b9 100644
> --- a/drivers/firmware/arm_scmi/driver.c
> +++ b/drivers/firmware/arm_scmi/driver.c
> @@ -1430,7 +1430,7 @@ static int scmi_probe(struct platform_device *pdev)
>
> ret = scmi_xfer_info_init(info);
> if (ret)
> - return ret;
> + goto clear_txrx_setup;
>
> if (scmi_notification_init(handle))
> dev_err(dev, "SCMI Notifications NOT available.\n");
> @@ -1443,7 +1443,7 @@ static int scmi_probe(struct platform_device *pdev)
> ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE);
> if (ret) {
> dev_err(dev, "unable to communicate with SCMI\n");
> - return ret;
> + goto notification_exit;
> }
>
> mutex_lock(&scmi_list_mutex);
> @@ -1482,6 +1482,13 @@ static int scmi_probe(struct platform_device *pdev)
> }
>
> return 0;
> +
> +notification_exit:
> + scmi_notification_exit(&info->handle);
> +clear_txrx_setup:
> + idr_for_each(&info->tx_idr, info->desc->ops->chan_free, &info->tx_idr);
> + idr_for_each(&info->rx_idr, info->desc->ops->chan_free, &info->rx_idr);
> + return ret;
> }
>
Shouldn't we also clear the internal IDRs memory allocs after these
idr_for_each() adding a couple of:
idr_destroy(&info->tx_idr);
idr_destroy(&info->rx_idr);
like scmi_remove() does ?
Thanks,
Cristian
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails
2021-08-04 8:33 ` [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails Cristian Marussi
@ 2021-08-04 8:40 ` Cristian Marussi
0 siblings, 0 replies; 2+ messages in thread
From: Cristian Marussi @ 2021-08-04 8:40 UTC (permalink / raw)
To: Rishabh Bhatnagar
Cc: sudeep.holla, linux-arm-kernel, linux-kernel, avajid, adharmap
On Wed, Aug 04, 2021 at 09:33:58AM +0100, Cristian Marussi wrote:
> On Tue, Aug 03, 2021 at 03:22:22PM -0700, Rishabh Bhatnagar wrote:
> > Mailbox channels for the base protocol are setup during probe.
> > There can be a scenario where probe fails to acquire the base
> > protocol due to a timeout leading to cleaning up of all device
> > managed memory including the scmi_mailbox structure setup during
> > mailbox_chan_setup function.
> > [ 12.735104]arm-scmi soc:qcom,scmi: timed out in resp(caller: version_get+0x84/0x140)
> > [ 12.735224]arm-scmi soc:qcom,scmi: unable to communicate with SCMI
> > [ 12.735947]arm-scmi: probe of soc:qcom,scmi failed with error -110
> >
> > Now when a message arrives at cpu slightly after the timeout, the mailbox
> > controller will try to call the rx_callback of the client and might end
> > up accessing freed memory.
> > [ 12.758363][ C0] Call trace:
> > [ 12.758367][ C0] rx_callback+0x24/0x160
> > [ 12.758372][ C0] mbox_chan_received_data+0x44/0x94
> > [ 12.758386][ C0] __handle_irq_event_percpu+0xd4/0x240
> > This patch frees the mailbox channels setup during probe and adds some more
> > error handling in case the probe fails.
> >
> > Change-Id: I1214ec2c4c92c4a3ca5fa73de11e0e403b13b46a
> > Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
>
> Hi Rishabh,
>
> Good catch, thanks for this.
>
Hi again,
sorry forgot one thing.
> > ---
> > drivers/firmware/arm_scmi/driver.c | 11 +++++++++--
> > 1 file changed, 9 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
> > index 9b2e8d4..518c7b9 100644
> > --- a/drivers/firmware/arm_scmi/driver.c
> > +++ b/drivers/firmware/arm_scmi/driver.c
> > @@ -1430,7 +1430,7 @@ static int scmi_probe(struct platform_device *pdev)
> >
> > ret = scmi_xfer_info_init(info);
> > if (ret)
> > - return ret;
> > + goto clear_txrx_setup;
> >
> > if (scmi_notification_init(handle))
> > dev_err(dev, "SCMI Notifications NOT available.\n");
> > @@ -1443,7 +1443,7 @@ static int scmi_probe(struct platform_device *pdev)
> > ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE);
> > if (ret) {
> > dev_err(dev, "unable to communicate with SCMI\n");
> > - return ret;
> > + goto notification_exit;
> > }
> >
> > mutex_lock(&scmi_list_mutex);
> > @@ -1482,6 +1482,13 @@ static int scmi_probe(struct platform_device *pdev)
> > }
> >
> > return 0;
> > +
> > +notification_exit:
> > + scmi_notification_exit(&info->handle);
> > +clear_txrx_setup:
> > + idr_for_each(&info->tx_idr, info->desc->ops->chan_free, &info->tx_idr);
> > + idr_for_each(&info->rx_idr, info->desc->ops->chan_free, &info->rx_idr);
> > + return ret;
> > }
> >
>
> Shouldn't we also clear the internal IDRs memory allocs after these
> idr_for_each() adding a couple of:
>
> idr_destroy(&info->tx_idr);
>
> idr_destroy(&info->rx_idr);
>
> like scmi_remove() does ?
>
Maybe it could be worth at this point unifying this common "cleanup-all-channels"
logic shared between scmi_probe()-error-path and scmi_remove() into its own
helper function to call from both sites.
Thanks,
Cristian
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linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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2021-08-04 8:33 ` [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails Cristian Marussi
2021-08-04 8:40 ` Cristian Marussi
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