devcoredump: Send uevent once devcd is ready

commit af54d778a0 upstream.

dev_coredumpm() creates a devcoredump device and adds it
to the core kernel framework which eventually end up
sending uevent to the user space and later creates a
symbolic link to the failed device. An application
running in userspace may be interested in this symbolic
link to get the name of the failed device.

In a issue scenario, once uevent sent to the user space
it start reading '/sys/class/devcoredump/devcdX/failing_device'
to get the actual name of the device which might not been
created and it is in its path of creation.

To fix this, suppress sending uevent till the failing device
symbolic link gets created and send uevent once symbolic
link is created successfully.

Fixes: 833c95456a ("device coredump: add new device coredump class")
Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1700232572-25823-1-git-send-email-quic_mojha@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mukesh Ojha 2023-11-17 20:19:32 +05:30 committed by Greg Kroah-Hartman
parent 74799b43d8
commit 0553d52908

View file

@ -363,6 +363,7 @@ void dev_coredumpm(struct device *dev, struct module *owner,
devcd->devcd_dev.class = &devcd_class;
mutex_lock(&devcd->mutex);
dev_set_uevent_suppress(&devcd->devcd_dev, true);
if (device_add(&devcd->devcd_dev))
goto put_device;
@ -377,6 +378,8 @@ void dev_coredumpm(struct device *dev, struct module *owner,
"devcoredump"))
dev_warn(dev, "devcoredump create_link failed\n");
dev_set_uevent_suppress(&devcd->devcd_dev, false);
kobject_uevent(&devcd->devcd_dev.kobj, KOBJ_ADD);
INIT_DELAYED_WORK(&devcd->del_wk, devcd_del);
schedule_delayed_work(&devcd->del_wk, DEVCD_TIMEOUT);
mutex_unlock(&devcd->mutex);