user/sven/linux.git/drivers/base/swnode.c, branch v5.4.90

Revert "software node: Simplify software_node_release() function"

2020-05-10T08:31:30Z

commit 7589238a8cf37331607c3222a64ac3140b29532d upstream. This reverts commit 3df85a1ae51f6b256982fe9d17c2dc5bfb4cc402. The reverted commit says "It's possible to release the node ID immediately when fwnode_remove_software_node() is called, no need to wait for software_node_release() with that." However, releasing the node ID before waiting for software_node_release() to be called causes the node ID to be released before the kobject and the underlying sysfs entry; this means there is a period of time where a sysfs entry exists that is associated with an unallocated node ID. Once consequence of this is that there is a race condition where it is possible to call fwnode_create_software_node() with no parent node specified (NULL) and have it fail with -EEXIST because the node ID that was assigned is still associated with a stale sysfs entry that hasn't been cleaned up yet. Although it is difficult to reproduce this race condition under normal conditions, it can be deterministically reproduced with the following minconfig on UML: CONFIG_KUNIT_DRIVER_PE_TEST=y CONFIG_DEBUG_KERNEL=y CONFIG_DEBUG_OBJECTS=y CONFIG_DEBUG_OBJECTS_TIMERS=y CONFIG_DEBUG_KOBJECT_RELEASE=y CONFIG_KUNIT=y Running the tests with this configuration causes the following failure: kobject: 'node0' ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed 400) ok 1 - pe_test_uints sysfs: cannot create duplicate filename '/kernel/software_nodes/node0' CPU: 0 PID: 28 Comm: kunit_try_catch Not tainted 5.6.0-rc3-next-20200227 #14 kobject_add_internal failed for node0 with -EEXIST, don't try to register things with the same name in the same directory. kobject: 'node0' ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed 100) # pe_test_uint_arrays: ASSERTION FAILED at drivers/base/test/property-entry-test.c:123 Expected node is not error, but is: -17 not ok 2 - pe_test_uint_arrays Reported-by: Heidi Fahim Signed-off-by: Brendan Higgins Reviewed-by: Heikki Krogerus Cc: 5.3+ # 5.3+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

software node: Get reference to parent swnode in get_parent op

2020-01-26T09:01:04Z

[ Upstream commit 51c100a651a471fcb8ead1ecc1224471eb0d61b9 ] The software_node_get_parent() returned a pointer to the parent swnode, but did not take a reference to it, leading the caller to put a reference that was not taken. Take that reference now. Fixes: 59abd83672f7 ("drivers: base: Introducing software nodes to the firmware node framework") Signed-off-by: Sakari Ailus Reviewed-by: Heikki Krogerus Reviewed-by: Andy Shevchenko Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

software node: Initialize the return value in software_node_find_by_name()

2019-09-11T17:10:12Z

The software node is searched from a list that may be empty when the function is called. This makes sure that the function returns NULL if the list is empty. Fixes: 1666faedb567 ("software node: Add software_node_find_by_name()") Reported-by: kbuild test robot Reported-by: Dan Carpenter Signed-off-by: Heikki Krogerus Reviewed-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki

software node: Initialize the return value in software_node_to_swnode()

2019-09-04T21:03:19Z

The software node is searched from a list that may be empty when the function is called. This makes sure that the function returns NULL even if the list is empty. Fixes: 80488a6b1d3c ("software node: Add support for static node descriptors") Reported-by: kbuild test robot Reported-by: Dan Carpenter Signed-off-by: Heikki Krogerus Reviewed-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki

software node: Add software_node_find_by_name()

2019-08-26T09:35:13Z

Function that searches software nodes by node name. Signed-off-by: Heikki Krogerus Reviewed-by: Hans de Goede Tested-by: Hans de Goede Reviewed-by: Andy Shevchenko Signed-off-by: Rafael J. Wysocki

software node: Add software_node_get_reference_args()

2019-06-03T08:55:38Z

This makes it possible to support drivers that use fwnode_property_get_reference_args() function. Signed-off-by: Heikki Krogerus Tested-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

software node: Use kobject name when finding child nodes by name

2019-06-03T08:55:38Z

Using the kobject name of the node instead of a device property "name" in software_node_get_named_child_node(). Signed-off-by: Heikki Krogerus Tested-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

software node: Add support for static node descriptors

2019-06-03T08:55:38Z

Until now the software nodes could only be created dynamically with fwnode_create_software_node() function. This introduces struct software_node data structure, which makes it possible to describe the software nodes also statically. The statically described software nodes can be registered with a new function fwnode_register_software_node(). This also adds a helper fwnode_register_software_nodes() which makes it possible to register an array of struct software_nodes, i.e. multiple nodes at the same time. There is no difference between statically described and dynamically allocated software nodes. Even the registration does not differ, except that during node creation the device properties are only copied if the node is created dynamically. With statically described nodes, the property entries in the descriptor (struct software_node) are assigned directly to the new software node that is being created without any copies. Signed-off-by: Heikki Krogerus Tested-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

software node: Simplify software_node_release() function

2019-06-03T08:55:38Z

It's possible to release the node ID immediately when fwnode_remove_software_node() is called, no need to wait for software_node_release() with that. Signed-off-by: Heikki Krogerus Tested-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

software node: Allow node creation without properties

2019-06-03T08:55:38Z

Software nodes are not forced to have device properties. Adding check to property_entries_dup() to make it possible to create software nodes that don't have any properties. Signed-off-by: Heikki Krogerus Tested-by: Hans de Goede Signed-off-by: Rafael J. Wysocki