On 01/29/18 06:42, Rob Herring wrote: > On Sun, Jan 28, 2018 at 8:53 PM, <frowand.list@xxxxxxxxx> wrote: >> From: Frank Rowand <frank.rowand@xxxxxxxx> >> >> 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 device tree (aka expanded device tree, EDT) now > > Not really a fan of a new acronym. > >> belongs to devicetree code, which is thus responsible for freeing >> the EDT. >> >> These ownership changes prevent early freeing of the duplicated FDT >> or the EDT, 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. I should have reversed the cause and effect in that sentence to instead be: The changes to drivers/of/unittest.c require the test overlays to be in FDT form instead of unflattened devicetree form. Move overlay fragments from artificial locations in drivers/of/unittest-data/tests-overlay.dtsi into one devicetree source file per overlay and thus create one FDT per overlay. > Why the rearranging? That should be a separate patch. Bisectability. I can make the changes to the devicetree files in a second patch. After the first patch, there will be 29 self test fails. I will make the change unless you respond back to this saying not to. >> - 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. > > For this? > >> - 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 overlay >> EDT 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. >> >> Errors while developing the patch exposed inadequate error messages >> to debug problems when overlay devicetree fragment nodes contain >> an invalid target path. Improved the messages in find_target_node(). > > Sounds like another separate patch. Will do. > > Rob > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
