Messages in this thread | | | Subject | Re: [PATCH] platform/chrome: cros_ec_rpmsg: Fix race with host command when probe failed. | From | Enric Balletbo i Serra <> | Date | Thu, 19 Sep 2019 15:04:26 +0200 |
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Hi,
On 4/9/19 8:26, Pi-Hsun Shih wrote: > Since the rpmsg_endpoint is created before probe is called, it's > possible that a host event is received during cros_ec_register, and > there would be some pending work in the host_event_work workqueue while > cros_ec_register is called. > > If cros_ec_register fails, when the leftover work in host_event_work > run, the ec_dev from the drvdata of the rpdev could be already set to > NULL, causing kernel crash when trying to run cros_ec_get_next_event. > > Fix this by creating the rpmsg_endpoint by ourself, and when > cros_ec_register fails (or on remove), destroy the endpoint first (to > make sure there's no more new calls to cros_ec_rpmsg_callback), and then > cancel all works in the host_event_work workqueue. > > Fixes: 2de89fd98958 ("platform/chrome: cros_ec: Add EC host command support using rpmsg") > Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org> > ---
Added the stable tag and applied for 5.4, the patches went to linux-next some time ago, so sorry for late notice.
Thanks, Enric
> drivers/platform/chrome/cros_ec_rpmsg.c | 33 +++++++++++++++++++++---- > 1 file changed, 28 insertions(+), 5 deletions(-) > > diff --git a/drivers/platform/chrome/cros_ec_rpmsg.c b/drivers/platform/chrome/cros_ec_rpmsg.c > index 8b6bd775cc9a..0c3738c3244d 100644 > --- a/drivers/platform/chrome/cros_ec_rpmsg.c > +++ b/drivers/platform/chrome/cros_ec_rpmsg.c > @@ -41,6 +41,7 @@ struct cros_ec_rpmsg { > struct rpmsg_device *rpdev; > struct completion xfer_ack; > struct work_struct host_event_work; > + struct rpmsg_endpoint *ept; > }; > > /** > @@ -72,7 +73,6 @@ static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev, > struct cros_ec_command *ec_msg) > { > struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; > - struct rpmsg_device *rpdev = ec_rpmsg->rpdev; > struct ec_host_response *response; > unsigned long timeout; > int len; > @@ -85,7 +85,7 @@ static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev, > dev_dbg(ec_dev->dev, "prepared, len=%d\n", len); > > reinit_completion(&ec_rpmsg->xfer_ack); > - ret = rpmsg_send(rpdev->ept, ec_dev->dout, len); > + ret = rpmsg_send(ec_rpmsg->ept, ec_dev->dout, len); > if (ret) { > dev_err(ec_dev->dev, "rpmsg send failed\n"); > return ret; > @@ -196,11 +196,24 @@ static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data, > return 0; > } > > +static struct rpmsg_endpoint * > +cros_ec_rpmsg_create_ept(struct rpmsg_device *rpdev) > +{ > + struct rpmsg_channel_info chinfo = {}; > + > + strscpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE); > + chinfo.src = rpdev->src; > + chinfo.dst = RPMSG_ADDR_ANY; > + > + return rpmsg_create_ept(rpdev, cros_ec_rpmsg_callback, NULL, chinfo); > +} > + > static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev) > { > struct device *dev = &rpdev->dev; > struct cros_ec_rpmsg *ec_rpmsg; > struct cros_ec_device *ec_dev; > + int ret; > > ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL); > if (!ec_dev) > @@ -225,7 +238,18 @@ static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev) > INIT_WORK(&ec_rpmsg->host_event_work, > cros_ec_rpmsg_host_event_function); > > - return cros_ec_register(ec_dev); > + ec_rpmsg->ept = cros_ec_rpmsg_create_ept(rpdev); > + if (!ec_rpmsg->ept) > + return -ENOMEM; > + > + ret = cros_ec_register(ec_dev); > + if (ret < 0) { > + rpmsg_destroy_ept(ec_rpmsg->ept); > + cancel_work_sync(&ec_rpmsg->host_event_work); > + return ret; > + } > + > + return 0; > } > > static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev) > @@ -234,7 +258,7 @@ static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev) > struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; > > cros_ec_unregister(ec_dev); > - > + rpmsg_destroy_ept(ec_rpmsg->ept); > cancel_work_sync(&ec_rpmsg->host_event_work); > } > > @@ -271,7 +295,6 @@ static struct rpmsg_driver cros_ec_driver_rpmsg = { > }, > .probe = cros_ec_rpmsg_probe, > .remove = cros_ec_rpmsg_remove, > - .callback = cros_ec_rpmsg_callback, > }; > > module_rpmsg_driver(cros_ec_driver_rpmsg); >
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