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authorPi-Hsun Shih <pihsun@chromium.org>2019-09-04 14:26:13 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-05 15:12:39 +0200
commitd0b85a37c06b3495ecf8268c7670339af3a21fce (patch)
tree13311f3aa83f411b7fb34b22c97721d1006664a7
parentbec8c6dec6058e4657ceab0fdae5a4ef0c041d3c (diff)
platform/chrome: cros_ec_rpmsg: Fix race with host command when probe failed
[ Upstream commit 71cddb7097e2b0feb855d7fd7d59afd12cbee4bb ] 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: 2de89fd98958 ("platform/chrome: cros_ec: Add EC host command support using rpmsg") Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/platform/chrome/cros_ec_rpmsg.c32
1 files changed, 28 insertions, 4 deletions
diff --git a/drivers/platform/chrome/cros_ec_rpmsg.c b/drivers/platform/chrome/cros_ec_rpmsg.c
index 5d3fb2abad1d..bec19d4814ab 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)
@@ -233,6 +257,7 @@ static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev)
struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
+ rpmsg_destroy_ept(ec_rpmsg->ept);
cancel_work_sync(&ec_rpmsg->host_event_work);
}
@@ -249,7 +274,6 @@ 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);