kernel/linux.git/drivers/of/resolver.c, branch v6.12.80

of: resolver: Fix device node refcount leakage in of_resolve_phandles()

2025-05-02T05:58:55+00:00

[ Upstream commit a46a0805635d07de50c2ac71588345323c13b2f9 ] In of_resolve_phandles(), refcount of device node @local_fixups will be increased if the for_each_child_of_node() exits early, but nowhere to decrease the refcount, so cause refcount leakage for the node. Fix by using __free() on @local_fixups. Fixes: da56d04c806a ("of/resolver: Switch to new local fixups format.") Cc: stable@vger.kernel.org Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250209-of_irq_fix-v2-9-93e3a2659aa7@quicinc.com [robh: Use __free() instead] Signed-off-by: Rob Herring (Arm) Signed-off-by: Sasha Levin

of: resolver: Simplify of_resolve_phandles() using __free()

2025-05-02T05:58:55+00:00

[ Upstream commit 5275e8b5293f65cc82a5ee5eab02dd573b911d6e ] Use the __free() cleanup to simplify of_resolve_phandles() and remove all the goto's. Signed-off-by: Rob Herring (Arm) Stable-dep-of: a46a0805635d ("of: resolver: Fix device node refcount leakage in of_resolve_phandles()") Signed-off-by: Sasha Levin

of: resolver: Simplify with scoped for each OF child loop

2024-08-26T15:50:46+00:00

Use scoped for_each_child_of_node_scoped() when iterating over device nodes to make code a bit simpler. Signed-off-by: Jinjie Ruan Link: https://lore.kernel.org/r/20240826062408.2406734-4-ruanjinjie@huawei.com Signed-off-by: Rob Herring (Arm)

of: Use scope based kfree() cleanups

2024-04-15T13:40:40+00:00

Use the relatively new scope based kfree() cleanup to simplify error handling. Doing so reduces the chances of memory leaks and simplifies error paths by avoiding the need for goto statements. Reviewed-by: Saravana Kannan Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240409-dt-cleanup-free-v2-2-5b419a4af38d@kernel.org Signed-off-by: Rob Herring

of: overlay: log the error cause on resolver failure

2020-03-02T17:32:44+00:00

When a DT overlay has a node label that is not present in the live devicetree symbols table, this error is printed: OF: resolver: overlay phandle fixup failed: -22 create_overlay: Failed to create overlay (err=-22) which does not help much in finding the node label that caused the problem and fix the overlay source. Add an error message with the name of the node label that caused the error. The new output is: OF: resolver: node label 'gpio9' not found in live devicetree symbols table OF: resolver: overlay phandle fixup failed: -22 create_overlay: Failed to create overlay (err=-22) Signed-off-by: Luca Ceresoli Reviewed-by: Frank Rowand Reviewed-by: Geert Uytterhoeven Signed-off-by: Rob Herring

of: resolver: Add of_node_put() before return and break

2019-08-12T22:52:24+00:00

Each iteration of for_each_child_of_node puts the previous node, but in the case of a return or break from the middle of the loop, there is no put, thus causing a memory leak. Hence add an of_node_put before the return or break in three places. Issue found with Coccinelle. Signed-off-by: Nishka Dasgupta Signed-off-by: Rob Herring

of: Use of_node_name_eq for node name comparisons

2018-12-05T20:45:13+00:00

Convert string compares of DT node names to use of_node_name_eq helper instead. This removes direct access to the node name pointer. Cc: Frank Rowand Cc: Pantelis Antoniou Cc: devicetree@vger.kernel.org Signed-off-by: Rob Herring

of: overlay: validate offset from property fixups

2018-05-23T20:07:43+00:00

The smatch static checker marks the data in offset as untrusted, leading it to warn: drivers/of/resolver.c:125 update_usages_of_a_phandle_reference() error: buffer underflow 'prop->value' 's32min-s32max' Add check to verify that offset is within the property data. Reported-by: Dan Carpenter Signed-off-by: Frank Rowand Cc: Signed-off-by: Rob Herring

of: cache phandle nodes to reduce cost of of_find_node_by_phandle()

2018-03-07T20:50:09+00:00

Create a cache of the nodes that contain a phandle property. Use this cache to find the node for a given phandle value instead of scanning the devicetree to find the node. If the phandle value is not found in the cache, of_find_node_by_phandle() will fall back to the tree scan algorithm. The cache is initialized in of_core_init(). The cache is freed via a late_initcall_sync() if modules are not enabled. If the devicetree is created by the dtc compiler, with all phandle property values auto generated, then the size required by the cache could be 4 * (1 + number of phandles) bytes. This results in an O(1) node lookup cost for a given phandle value. Due to a concern that the phandle property values might not be consistent with what is generated by the dtc compiler, a mask has been added to the cache lookup algorithm. To maintain the O(1) node lookup cost, the size of the cache has been increased by rounding the number of entries up to the next power of two. The overhead of finding the devicetree node containing a given phandle value has been noted by several people in the recent past, in some cases with a patch to add a hashed index of devicetree nodes, based on the phandle value of the node. One concern with this approach is the extra space added to each node. This patch takes advantage of the phandle property values auto generated by the dtc compiler, which begin with one and monotonically increase by one, resulting in a range of 1..n for n phandle values. This implementation should also provide a good reduction of overhead for any range of phandle values that are mostly in a monotonic range. Performance measurements by Chintan Pandya of several implementations of patches that are similar to this one suggest an expected reduction of boot time by ~400ms for his test system. If the cache size was decreased to 64 entries, the boot time was reduced by ~340 ms. The measurements were on a 4.9.73 kernel for arch/arm64/boot/dts/qcom/sda670-mtp.dts, contains 2371 nodes and 814 phandle values. Reported-by: Chintan Pandya Signed-off-by: Frank Rowand Signed-off-by: Rob Herring

of: change overlay apply input data from unflattened to FDT

2018-03-04T08:29:24+00:00

Move duplicating and unflattening of an overlay flattened devicetree (FDT) into the overlay application code. To accomplish this, of_overlay_apply() is replaced by of_overlay_fdt_apply(). The copy of the FDT (aka "duplicate FDT") now belongs to devicetree code, which is thus responsible for freeing the duplicate FDT. The caller of of_overlay_fdt_apply() remains responsible for freeing the original FDT. The unflattened devicetree now belongs to devicetree code, which is thus responsible for freeing the unflattened devicetree. These ownership changes prevent early freeing of the duplicated FDT or the unflattened devicetree, which could result in use after free errors. of_overlay_fdt_apply() is a private function for the anticipated overlay loader. Update unittest.c to use of_overlay_fdt_apply() instead of of_overlay_apply(). Move overlay fragments from artificial locations in drivers/of/unittest-data/tests-overlay.dtsi into one devicetree source file per overlay. This led to changes in drivers/of/unitest-data/Makefile and drivers/of/unitest.c. - Add overlay directives to the overlay devicetree source files so that dtc will compile them as true overlays into one FDT data chunk per overlay. - Set CFLAGS for drivers/of/unittest-data/testcases.dts so that symbols will be generated for overlay resolution of overlays that are no longer artificially contained in testcases.dts - Unflatten and apply each unittest overlay FDT using of_overlay_fdt_apply(). - Enable the of_resolve_phandles() check for whether the unflattened overlay is detached. This check was previously disabled because the overlays from tests-overlay.dtsi were not unflattened into detached trees. - Other changes to unittest.c infrastructure to manage multiple test FDTs built into the kernel image (access by name instead of arbitrary number). - of_unittest_overlay_high_level(): previously unused code to add properties from the overlay_base devicetree to the live tree was triggered by the restructuring of tests-overlay.dtsi and thus testcases.dts. This exposed two bugs: (1) the need to dup a property before adding it, and (2) property 'name' is auto-generated in the unflatten code and thus will be a duplicate in the __symbols__ node - do not treat this duplicate as an error. Signed-off-by: Frank Rowand