From: Saravana Kannan saravanak@google.com
mainline inclusion from mainline-v5.13-rc1 commit b6f617df4fa936c1ab1831c2b23563f6c1add6c4 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7R8MK CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Device link status was not getting updated correctly when device_bind_driver() is called on a device. This causes a warning[1]. Fix this by updating device links that can be updated and dropping device links that can't be updated to a sensible state.
[1] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com...
Tested-by: Jon Hunter jonathanh@nvidia.com Signed-off-by: Saravana Kannan saravanak@google.com Link: https://lore.kernel.org/r/20210302211133.2244281-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Guo Mengqi guomengqi3@huawei.com --- drivers/base/base.h | 1 + drivers/base/core.c | 35 +++++++++++++++++++++++++++++++++++ drivers/base/dd.c | 4 +++- 3 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/drivers/base/base.h b/drivers/base/base.h index 7d97447460fa..54e51876613c 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -186,6 +186,7 @@ extern int device_links_read_lock(void); extern void device_links_read_unlock(int idx); extern int device_links_read_lock_held(void); extern int device_links_check_suppliers(struct device *dev); +extern void device_links_force_bind(struct device *dev); extern void device_links_driver_bound(struct device *dev); extern void device_links_driver_cleanup(struct device *dev); extern void device_links_no_driver(struct device *dev); diff --git a/drivers/base/core.c b/drivers/base/core.c index af0024a9aa7c..1559caa7cbe9 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1099,6 +1099,41 @@ static ssize_t waiting_for_supplier_show(struct device *dev, } static DEVICE_ATTR_RO(waiting_for_supplier);
+/** + * device_links_force_bind - Prepares device to be force bound + * @dev: Consumer device. + * + * device_bind_driver() force binds a device to a driver without calling any + * driver probe functions. So the consumer really isn't going to wait for any + * supplier before it's bound to the driver. We still want the device link + * states to be sensible when this happens. + * + * In preparation for device_bind_driver(), this function goes through each + * supplier device links and checks if the supplier is bound. If it is, then + * the device link status is set to CONSUMER_PROBE. Otherwise, the device link + * is dropped. Links without the DL_FLAG_MANAGED flag set are ignored. + */ +void device_links_force_bind(struct device *dev) +{ + struct device_link *link, *ln; + + device_links_write_lock(); + + list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) { + if (!(link->flags & DL_FLAG_MANAGED)) + continue; + + if (link->status != DL_STATE_AVAILABLE) { + device_link_drop_managed(link); + continue; + } + WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE); + } + dev->links.status = DL_DEV_PROBING; + + device_links_write_unlock(); +} + /** * device_links_driver_bound - Update device links after probing its driver. * @dev: Device to update the links for. diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 5dee895e41ed..f697eb02c221 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -460,8 +460,10 @@ int device_bind_driver(struct device *dev) int ret;
ret = driver_sysfs_add(dev); - if (!ret) + if (!ret) { + device_links_force_bind(dev); driver_bound(dev); + } else if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DRIVER_NOT_BOUND, dev);