Commit 71cddb70 authored by Pi-Hsun Shih's avatar Pi-Hsun Shih Committed by Enric Balletbo i Serra

platform/chrome: cros_ec_rpmsg: Fix race with host command when probe failed

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.

Cc: stable@vger.kernel.org
Fixes: 2de89fd9 ("platform/chrome: cros_ec: Add EC host command support using rpmsg")
Signed-off-by: default avatarPi-Hsun Shih <pihsun@chromium.org>
Signed-off-by: default avatarEnric Balletbo i Serra <enric.balletbo@collabora.com>
parent 0144c00e
...@@ -41,6 +41,7 @@ struct cros_ec_rpmsg { ...@@ -41,6 +41,7 @@ struct cros_ec_rpmsg {
struct rpmsg_device *rpdev; struct rpmsg_device *rpdev;
struct completion xfer_ack; struct completion xfer_ack;
struct work_struct host_event_work; 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, ...@@ -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_command *ec_msg)
{ {
struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
struct rpmsg_device *rpdev = ec_rpmsg->rpdev;
struct ec_host_response *response; struct ec_host_response *response;
unsigned long timeout; unsigned long timeout;
int len; int len;
...@@ -85,7 +85,7 @@ static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev, ...@@ -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); dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
reinit_completion(&ec_rpmsg->xfer_ack); 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) { if (ret) {
dev_err(ec_dev->dev, "rpmsg send failed\n"); dev_err(ec_dev->dev, "rpmsg send failed\n");
return ret; return ret;
...@@ -196,11 +196,24 @@ static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data, ...@@ -196,11 +196,24 @@ static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
return 0; 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) static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev)
{ {
struct device *dev = &rpdev->dev; struct device *dev = &rpdev->dev;
struct cros_ec_rpmsg *ec_rpmsg; struct cros_ec_rpmsg *ec_rpmsg;
struct cros_ec_device *ec_dev; struct cros_ec_device *ec_dev;
int ret;
ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL); ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
if (!ec_dev) if (!ec_dev)
...@@ -225,7 +238,18 @@ static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev) ...@@ -225,7 +238,18 @@ static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev)
INIT_WORK(&ec_rpmsg->host_event_work, INIT_WORK(&ec_rpmsg->host_event_work,
cros_ec_rpmsg_host_event_function); 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) static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev)
...@@ -234,7 +258,7 @@ 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; struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
cros_ec_unregister(ec_dev); cros_ec_unregister(ec_dev);
rpmsg_destroy_ept(ec_rpmsg->ept);
cancel_work_sync(&ec_rpmsg->host_event_work); cancel_work_sync(&ec_rpmsg->host_event_work);
} }
...@@ -271,7 +295,6 @@ static struct rpmsg_driver cros_ec_driver_rpmsg = { ...@@ -271,7 +295,6 @@ static struct rpmsg_driver cros_ec_driver_rpmsg = {
}, },
.probe = cros_ec_rpmsg_probe, .probe = cros_ec_rpmsg_probe,
.remove = cros_ec_rpmsg_remove, .remove = cros_ec_rpmsg_remove,
.callback = cros_ec_rpmsg_callback,
}; };
module_rpmsg_driver(cros_ec_driver_rpmsg); module_rpmsg_driver(cros_ec_driver_rpmsg);
......
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