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author | Jan Kiszka <jan.kiszka@siemens.com> | 2018-04-26 13:00:30 +0200 |
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committer | Rob Herring <robh@kernel.org> | 2018-04-27 04:18:13 +0200 |
commit | 83ef4777f5ff3689e6e52d3913a13d79aa25f1b5 (patch) | |
tree | 59e9979916a0d2c16f9b90cb8147e63250215a18 /Documentation/devicetree/overlay-notes.txt | |
parent | dtc: checks: drop warning for missing PCI bridge bus-range (diff) | |
download | linux-83ef4777f5ff3689e6e52d3913a13d79aa25f1b5.tar.xz linux-83ef4777f5ff3689e6e52d3913a13d79aa25f1b5.zip |
of: overlay: Stop leaking resources on overlay removal
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 <jan.kiszka@siemens.com>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'Documentation/devicetree/overlay-notes.txt')
-rw-r--r-- | Documentation/devicetree/overlay-notes.txt | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt index a4feb6dde8cd..725fb8d255c1 100644 --- a/Documentation/devicetree/overlay-notes.txt +++ b/Documentation/devicetree/overlay-notes.txt @@ -98,6 +98,14 @@ Finally, if you need to remove all overlays in one-go, just call of_overlay_remove_all() which will remove every single one in the correct order. +In addition, there is the option to register notifiers that get called on +overlay operations. See of_overlay_notifier_register/unregister and +enum of_overlay_notify_action for details. + +Note that a notifier callback is not supposed to store pointers to a device +tree node or its content beyond OF_OVERLAY_POST_REMOVE corresponding to the +respective node it received. + Overlay DTS Format ------------------ |