kernel/linux.git/drivers/of/overlay.c, branch v4.19.112

of: overlay: add_changeset_property() memory leak

2019-12-17T19:35:56+00:00

[ Upstream commit 637392a8506a3a7dd24ab9094a14f7522adb73b4 ] No changeset entries are created for #address-cells and #size-cells properties, but the duplicated properties are never freed. This results in a memory leak which is detected by kmemleak: unreferenced object 0x85887180 (size 64): backtrace: kmem_cache_alloc_trace+0x1fb/0x1fc __of_prop_dup+0x25/0x7c add_changeset_property+0x17f/0x370 build_changeset_next_level+0x29/0x20c of_overlay_fdt_apply+0x32b/0x6b4 ... Fixes: 6f75118800ac ("of: overlay: validate overlay properties #address-cells and #size-cells") Reported-by: Vincent Whitchurch Signed-off-by: Frank Rowand Tested-by: Vincent Whitchurch Signed-off-by: Rob Herring Signed-off-by: Sasha Levin

of: overlay: set node fields from properties when add new overlay node

2019-06-09T07:17:24+00:00

commit f96278810150fc39085d1872e5b39ea06366d03e upstream. Overlay nodes added by add_changeset_node() do not have the node fields name, phandle, and type set. The node passed to __of_attach_node() when the add node changeset entry is processed does not contain any properties. The node's properties are located in add property changeset entries that will be processed after the add node changeset is applied. Set the node's fields in the node contained in the add node changeset entry and do not set them to incorrect values in add_changeset_node(). A visible symptom that is fixed by this patch is the names of nodes added by overlays that have an entry in /sys/bus/platform/drivers/*/ will contain the unit-address but the node-name will be , for example, "fc4ab000.". After applying the patch the name, in this example, for node restart@fc4ab000 is "fc4ab000.restart". Tested-by: Alan Tull Signed-off-by: Frank Rowand Cc: Phil Elwell Signed-off-by: Greg Kroah-Hartman

of: overlay: validate overlay properties #address-cells and #size-cells

2019-06-09T07:17:24+00:00

commit 6f75118800acf77f8ad6afec61ca1b2349ade371 upstream. If overlay properties #address-cells or #size-cells are already in the live devicetree for any given node, then the values in the overlay must match the values in the live tree. If the properties are already in the live tree then there is no need to create a changeset entry to add them since they must have the same value. This reduces the memory used by the changeset and eliminates a possible memory leak. Tested-by: Alan Tull Signed-off-by: Frank Rowand Signed-off-by: Greg Kroah-Hartman

of: overlay: do not duplicate properties from overlay for new nodes

2019-02-06T16:30:16+00:00

commit 8814dc46bd9e347d4de55ec5bf8f16ea54470499 upstream. When allocating a new node, add_changeset_node() was duplicating the properties from the respective node in the overlay instead of allocating a node with no properties. When this patch is applied the errors reported by the devictree unittest from patch "of: overlay: add tests to validate kfrees from overlay removal" will no longer occur. These error messages are of the form: "OF: ERROR: ..." and the unittest results will change from: ### dt-test ### end of unittest - 203 passed, 7 failed to ### dt-test ### end of unittest - 210 passed, 0 failed Tested-by: Alan Tull Signed-off-by: Frank Rowand Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

of: overlay: use prop add changeset entry for property in new nodes

2019-02-06T16:30:15+00:00

commit 6b4955ba7bc05e40c8c41071cc121bc26ca65277 upstream. The changeset entry 'update property' was used for new properties in an overlay instead of 'add property'. The decision of whether to use 'update property' was based on whether the property already exists in the subtree where the node is being spliced into. At the top level of creating a changeset describing the overlay, the target node is in the live devicetree, so checking whether the property exists in the target node returns the correct result. As soon as the changeset creation algorithm recurses into a new node, the target is no longer in the live devicetree, but is instead in the detached overlay tree, thus all properties are incorrectly found to already exist in the target. This fix will expose another devicetree bug that will be fixed in the following patch in the series. When this patch is applied the errors reported by the devictree unittest will change, and the unittest results will change from: ### dt-test ### end of unittest - 210 passed, 0 failed to ### dt-test ### end of unittest - 203 passed, 7 failed Tested-by: Alan Tull Signed-off-by: Frank Rowand Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

of: overlay: add tests to validate kfrees from overlay removal

2019-02-06T16:30:15+00:00

commit 144552c786925314c1e7cb8f91a71dae1aca8798 upstream. Add checks: - attempted kfree due to refcount reaching zero before overlay is removed - properties linked to an overlay node when the node is removed - node refcount > one during node removal in a changeset destroy, if the node was created by the changeset After applying this patch, several validation warnings will be reported from the devicetree unittest during boot due to pre-existing devicetree bugs. The warnings will be similar to: OF: ERROR: of_node_release(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11 OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/ hvac-medium-2 Tested-by: Alan Tull Signed-off-by: Frank Rowand Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

of: Convert to using %pOFn instead of device_node.name

2019-02-06T16:30:15+00:00

commit a613b26a50136ae90ab13943afe90bcbd34adb44 upstream. In preparation to remove the node name pointer from struct device_node, convert printf users to use the %pOFn format specifier. Reviewed-by: Frank Rowand Cc: Andrew Lunn Cc: Florian Fainelli Cc: netdev@vger.kernel.org Signed-off-by: Rob Herring Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

of: overlay: add missing of_node_put() after add new node to changeset

2019-01-26T08:32:34+00:00

[ Upstream commit 7c528e457d53c75107d5aa56892316d265c778de ] The refcount of a newly added overlay node decrements to one (instead of zero) when the overlay changeset is destroyed. This change will cause the final decrement be to zero. After applying this patch, new validation warnings will be reported from the devicetree unittest during boot due to a pre-existing devicetree bug. The warnings will be similar to: OF: ERROR: memory leak before free overlay changeset, /testcase-data/overlay-node/test-bus/test-unittest4 This pre-existing devicetree bug will also trigger a WARN_ONCE() from refcount_sub_and_test_checked() when an overlay changeset is destroyed without having first been applied. This scenario occurs when an error in the overlay is detected during the overlay changeset creation: WARNING: CPU: 0 PID: 1 at lib/refcount.c:187 refcount_sub_and_test_checked+0xa8/0xbc refcount_t: underflow; use-after-free. (unwind_backtrace) from (show_stack+0x10/0x14) (show_stack) from (dump_stack+0x6c/0x8c) (dump_stack) from (__warn+0xdc/0x104) (__warn) from (warn_slowpath_fmt+0x44/0x6c) (warn_slowpath_fmt) from (refcount_sub_and_test_checked+0xa8/0xbc) (refcount_sub_and_test_checked) from (kobject_put+0x24/0x208) (kobject_put) from (of_changeset_destroy+0x2c/0xb4) (of_changeset_destroy) from (free_overlay_changeset+0x1c/0x9c) (free_overlay_changeset) from (of_overlay_remove+0x284/0x2cc) (of_overlay_remove) from (of_unittest_apply_revert_overlay_check.constprop.4+0xf8/0x1e8) (of_unittest_apply_revert_overlay_check.constprop.4) from (of_unittest_overlay+0x960/0xed8) (of_unittest_overlay) from (of_unittest+0x1cc4/0x2138) (of_unittest) from (do_one_initcall+0x4c/0x28c) (do_one_initcall) from (kernel_init_freeable+0x29c/0x378) (kernel_init_freeable) from (kernel_init+0x8/0x110) (kernel_init) from (ret_from_fork+0x14/0x2c) Tested-by: Alan Tull Signed-off-by: Frank Rowand Signed-off-by: Sasha Levin

of: overlay: update phandle cache on overlay apply and remove

2018-07-16T14:41:32+00:00

A comment in the review of the patch adding the phandle cache said that the cache would have to be updated when modules are applied and removed. This patch implements the cache updates. Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()") Reported-by: Alan Tull Suggested-by: Alan Tull Signed-off-by: Frank Rowand Signed-off-by: Rob Herring

of: overlay: Stop leaking resources on overlay removal

2018-04-27T02:18:13+00:00

Only the overlay notifier callbacks have a chance to potentially get hold of references to those two resources, but they are not supposed to store them beyond OF_OVERLAY_POST_REMOVE. Document the overlay notifier API, its constraint regarding pointer lifetime, and then remove intentional leaks of ovcs->overlay_tree and ovcs->fdt from free_overlay_changeset. See also https://lkml.org/lkml/2018/4/23/1063 and following. Signed-off-by: Jan Kiszka Reviewed-by: Frank Rowand Signed-off-by: Rob Herring