kernel/linux.git/drivers/of/overlay.c, branch v5.6.17

of: overlay: kmemleak in dup_and_fixup_symbol_prop()

2020-04-23T08:37:54+00:00

commit 478ff649b1c8eb2409b1a54fb75eb46f7c29f140 upstream. kmemleak reports several memory leaks from devicetree unittest. This is the fix for problem 4 of 5. target_path was not freed in the non-error path. Fixes: e0a58f3e08d4 ("of: overlay: remove a dependency on device node full_name") Reported-by: Erhard F. Signed-off-by: Frank Rowand Signed-off-by: Rob Herring Signed-off-by: Greg Kroah-Hartman

of: overlay: Remove blank line between assignment and check

2020-01-08T16:49:23+00:00

There used to be blank lines between assignment and check of the __of_changeset_revert_entries() result, to make the phandle cache management operations stand out. After the removal of those operations in commit 90dc0d1ce890419f ("of: Rework and simplify phandle cache to use a fixed size"), there is no longer a reason to have such a blank line. Remove the blank line, to rejoin visibly the status assignement and check, and to match coding style. Signed-off-by: Geert Uytterhoeven Signed-off-by: Rob Herring

of: Rework and simplify phandle cache to use a fixed size

2019-12-24T21:17:52+00:00

The phandle cache was added to speed up of_find_node_by_phandle() by avoiding walking the whole DT to find a matching phandle. The implementation has several shortcomings: - The cache is designed to work on a linear set of phandle values. This is true for dtc generated DTs, but not for other cases such as Power. - The cache isn't enabled until of_core_init() and a typical system may see hundreds of calls to of_find_node_by_phandle() before that point. - The cache is freed and re-allocated when the number of phandles changes. - It takes a raw spinlock around a memory allocation which breaks on RT. Change the implementation to a fixed size and use hash_32() as the cache index. This greatly simplifies the implementation. It avoids the need for any re-alloc of the cache and taking a reference on nodes in the cache. We only have a single source of removing cache entries which is of_detach_node(). Using hash_32() removes any assumption on phandle values improving the hit rate for non-linear phandle values. The effect on linear values using hash_32() is about a 10% collision. The chances of thrashing on colliding values seems to be low. To compare performance, I used a RK3399 board which is a pretty typical system. I found that just measuring boot time as done previously is noisy and may be impacted by other things. Also bringing up secondary cores causes some issues with measuring, so I booted with 'nr_cpus=1'. With no caching, calls to of_find_node_by_phandle() take about 20124 us for 1248 calls. There's an additional 288 calls before time keeping is up. Using the average time per hit/miss with the cache, we can calculate these calls to take 690 us (277 hit / 11 miss) with a 128 entry cache and 13319 us with no cache or an uninitialized cache. Comparing the 3 implementations the time spent in of_find_node_by_phandle() is: no cache: 20124 us (+ 13319 us) 128 entry cache: 5134 us (+ 690 us) current cache: 819 us (+ 13319 us) We could move the allocation of the cache earlier to improve the current cache, but that just further complicates the situation as it needs to be after slab is up, so we can't do it when unflattening (which uses memblock). Reported-by: Sebastian Andrzej Siewior Cc: Michael Ellerman Cc: Segher Boessenkool Cc: Frank Rowand Acked-by: Sebastian Andrzej Siewior Reviewed-by: Frank Rowand Tested-by: Frank Rowand Signed-off-by: Rob Herring

of: overlay: add_changeset_property() memory leak

2019-11-26T19:32:21+00:00

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

of: Remove struct device_node.type pointer

2019-01-10T22:24:44+00:00

Now that all users of device_node.type pointer have been removed in favor of accessor functions, we can remove it. Cc: Frank Rowand Cc: devicetree@vger.kernel.org Signed-off-by: Rob Herring

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

2018-11-09T06:12:17+00:00

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

of: overlay: check prevents multiple fragments touching same property

2018-11-09T06:12:03+00:00

Add test case of two fragments updating the same property. After adding the test case, the system hangs at end of boot, after after slub stack dumps from kfree() in crypto modprobe code. Multiple overlay fragments adding, modifying, or deleting the same property is not supported. Add check to detect the attempt and fail the overlay apply. Before this patch, the first fragment error would terminate processing. Allow fragment checking to proceed and report all of the fragment errors before terminating the overlay apply. This is not a hot path, thus not a performance issue (the error is not transient and requires fixing the overlay before attempting to apply it again). After applying this patch, the devicetree unittest messages will include: OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/rpm_avail ... ### dt-test ### end of unittest - 212 passed, 0 failed The check to detect two fragments updating the same property is folded into the patch that created the test case to maintain bisectability. Tested-by: Alan Tull Signed-off-by: Frank Rowand

of: overlay: check prevents multiple fragments add or delete same node

2018-11-09T06:11:57+00:00

Multiple overlay fragments adding or deleting the same node is not supported. Replace code comment of such, with check to detect the attempt and fail the overlay apply. Devicetree unittest where multiple fragments added the same node was added in the previous patch in the series. After applying this patch the unittest messages will no longer include: Duplicate name in motor-1, renamed to "controller#1" OF: overlay: of_overlay_apply() err=0 ### dt-test ### of_overlay_fdt_apply() expected -22, ret=0, overlay_bad_add_dup_node ### dt-test ### FAIL of_unittest_overlay_high_level():2419 Adding overlay 'overlay_bad_add_dup_node' failed ... ### dt-test ### end of unittest - 210 passed, 1 failed but will instead include: OF: overlay: ERROR: multiple overlay fragments add and/or delete node /testcase-data-2/substation@100/motor-1/controller ... ### dt-test ### end of unittest - 211 passed, 0 failed Tested-by: Alan Tull Signed-off-by: Frank Rowand

of: overlay: make all pr_debug() and pr_err() messages unique

2018-11-09T06:11:39+00:00

Make overlay.c debug and error messages unique so that they can be unambiguously found by grep. Tested-by: Alan Tull Signed-off-by: Frank Rowand

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

2018-11-09T06:11:32+00:00

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