4.19-stable review patch. If anyone has any objections, please let me know.
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From: Mukesh Ojha quic_mojha@quicinc.com
[ Upstream commit af54d778a03853801d681c98c0c2a6c316ef9ca7 ]
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: 833c95456a70 ("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@quici... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/devcoredump.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c index 1ba4af7f2f21f..b13574cdef69b 100644 --- a/drivers/base/devcoredump.c +++ b/drivers/base/devcoredump.c @@ -376,6 +376,7 @@ 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;
@@ -387,6 +388,8 @@ void dev_coredumpm(struct device *dev, struct module *owner, "devcoredump")) /* nothing - symlink will be missing */;
+ 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);