user/sven/linux.git/drivers/of/resolver.c, branch v4.19.135

of: overlay: validate offset from property fixups

2018-05-23T20:07:43Z

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()

2018-03-07T20:50:09Z

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

2018-03-04T08:29:24Z

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

of: Use SPDX license tag for DT files

2018-01-08T14:22:45Z

Convert remaining DT files to use SPDX-License-Identifier tags. Cc: Benjamin Herrenschmidt Cc: Guennadi Liakhovetski Cc: Paul Mackerras Cc: Pantelis Antoniou Reviewed-by: Frank Rowand Reviewed-by: Philippe Ombredanne Signed-off-by: Rob Herring

of: overlay: avoid race condition between applying multiple overlays

2017-10-18T01:47:27Z

The process of applying an overlay consists of: - unflatten an overlay FDT (flattened device tree) into an EDT (expanded device tree) - fixup the phandle values in the overlay EDT to fit in a range above the phandle values in the live device tree - create the overlay changeset to reflect the contents of the overlay EDT - apply the overlay changeset, to modify the live device tree, potentially changing the maximum phandle value in the live device tree There is currently no protection against two overlay applies concurrently determining what range of phandle values are in use in the live device tree, and subsequently changing that range. Add a mutex to prevent multiple overlay applies from occurring simultaneously. Move of_resolve_phandles() into of_overlay_apply() so that it does not have to be duplicated by each caller of of_overlay_apply(). The test in of_resolve_phandles() that the overlay tree is detached is temporarily disabled so that old style overlay unittests do not fail. Signed-off-by: Frank Rowand Signed-off-by: Rob Herring

of/resolver: Replace kmalloc + memcpy with kmemdup()

2017-10-16T21:43:29Z

Save one line. Signed-off-by: Stephen Boyd Reviewed-by: Frank Rowand Signed-off-by: Rob Herring

of/resolver: Simplify to be32_add_cpu()

2017-10-16T21:42:56Z

This is the same as be32_add_cpu(), so simplify the code and remove the now unused local variable. Signed-off-by: Stephen Boyd Reviewed-by: Frank Rowand Signed-off-by: Rob Herring

of: find_node_by_full_name rewrite to compare each level

2017-06-22T17:38:29Z

find_node_by_full_name() does the same thing as of_find_node_by_path(), but takes no locks and doesn't work on aliases. Refactor of_find_node_opts_by_path() into __of_find_node_by_full_path() and replace find_node_by_full_name() with it. Signed-off-by: Rob Herring

of: use kbasename instead of open coding

2017-06-22T17:37:46Z

Several places in DT code open code the equivalent of kbasename. Replace them. The behavior for root nodes in node_name_cmp will be slightly different. Instead of comparing "/", "" will be compared. The comparison will be the same. Reviewed-by: Andy Shevchenko Signed-off-by: Rob Herring

of: fix sparse warnings in fdt, irq, reserved mem, and resolver code

2017-05-04T19:01:13Z

sparse generates the following warnings in drivers/of/: ../drivers/of/fdt.c:63:36: warning: cast to restricted __be32 ../drivers/of/fdt.c:68:33: warning: cast to restricted __be32 ../drivers/of/irq.c:105:88: warning: incorrect type in initializer (different base types) ../drivers/of/irq.c:105:88: expected restricted __be32 ../drivers/of/irq.c:105:88: got int ../drivers/of/irq.c:526:35: warning: incorrect type in assignment (different modifiers) ../drivers/of/irq.c:526:35: expected int ( *const [usertype] irq_init_cb )( ... ) ../drivers/of/irq.c:526:35: got void const *const data ../drivers/of/of_reserved_mem.c:200:50: warning: incorrect type in initializer (different modifiers) ../drivers/of/of_reserved_mem.c:200:50: expected int ( *[usertype] initfn )( ... ) ../drivers/of/of_reserved_mem.c:200:50: got void const *const data ../drivers/of/resolver.c:95:42: warning: incorrect type in assignment (different base types) ../drivers/of/resolver.c:95:42: expected unsigned int [unsigned] [usertype] ../drivers/of/resolver.c:95:42: got restricted __be32 [usertype] All these are harmless type mismatches fixed by adjusting the types. Signed-off-by: Rob Herring