[PATCH v2 00/18] of: overlay: validation checks, subsequent fixes

From: frowand . list
Date: Sat Oct 13 2018 - 00:55:18 EST


From: Frank Rowand <frank.rowand@xxxxxxxx>

Add checks to (1) overlay apply process and (2) memory freeing
triggered by overlay release. The checks are intended to detect
possible memory leaks and invalid overlays.

The checks revealed bugs in existing code. Fixed the bugs.

While fixing bugs, noted other issues, which are fixed in
separate patches.

***** Powerpc folks: I was not able to test the patches that
***** directly impact Powerpc systems that use dynamic
***** devicetree. Please review that code carefully and
***** test. The specific patches are: 03/16, 04/16, 07/16

FPGA folks:

I made the validation checks that should result in an
invalid live devicetree report "ERROR" and cause the overlay apply
to fail.

I made the memory leak validation tests report "WARNING" and allow
the overlay apply to complete successfully. Please let me know
if you encounter the warnings. There are at least two paths
forward to deal with the cases that trigger the warning: (1) change
the warning to an error and fail the overlay apply, or (2) find a
way to detect the potential memory leaks and free the memory
appropriately.

ALL people:

The validations do _not_ address another major concern I have with
releasing overlays, which is use after free errors.

Changes since v1:

- move patch 16/16 to 17/18
- move patch 15/16 to 18/18
- new patch 15/18
- new patch 16/18

- 05/18: add_changeset_node() header comment: incorrect comment for @target

- 18/18: add same fix for of_parse_phandle_with_args()
- 18/18: add same fix for of_parse_phandle_with_args_map()

Frank Rowand (18):
of: overlay: add tests to validate kfrees from overlay removal
of: overlay: add missing of_node_put() after add new node to changeset
of: overlay: add missing of_node_get() in __of_attach_node_sysfs
powerpc/pseries: add of_node_put() in dlpar_detach_node()
of: overlay: use prop add changeset entry for property in new nodes
of: overlay: do not duplicate properties from overlay for new nodes
of: dynamic: change type of of_{at,de}tach_node() to void
of: overlay: reorder fields in struct fragment
of: overlay: validate overlay properties #address-cells and
#size-cells
of: overlay: make all pr_debug() and pr_err() messages unique
of: overlay: test case of two fragments adding same node
of: overlay: check prevents multiple fragments add or delete same node
of: overlay: check prevents multiple fragments touching same property
of: unittest: remove unused of_unittest_apply_overlay() argument
of: overlay: set node fields from properties when add new overlay node
of: unittest: allow base devicetree to have symbol metadata
of: unittest: find overlays[] entry by name instead of index
of: unittest: initialize args before calling of_*parse_*()

arch/powerpc/platforms/pseries/dlpar.c | 15 +-
arch/powerpc/platforms/pseries/reconfig.c | 6 +-
drivers/of/dynamic.c | 68 +++--
drivers/of/kobj.c | 4 +-
drivers/of/overlay.c | 298 ++++++++++++++++-----
drivers/of/unittest-data/Makefile | 2 +
.../of/unittest-data/overlay_bad_add_dup_node.dts | 28 ++
.../of/unittest-data/overlay_bad_add_dup_prop.dts | 24 ++
drivers/of/unittest-data/overlay_base.dts | 1 +
drivers/of/unittest.c | 96 +++++--
include/linux/of.h | 19 +-
11 files changed, 439 insertions(+), 122 deletions(-)
create mode 100644 drivers/of/unittest-data/overlay_bad_add_dup_node.dts
create mode 100644 drivers/of/unittest-data/overlay_bad_add_dup_prop.dts

--
Frank Rowand <frank.rowand@xxxxxxxx>