linux/drivers/of
Frank Rowand 7c528e457d of: overlay: add missing of_node_put() after add new node to changeset
The refcount of a newly added overlay node decrements to one
(instead of zero) when the overlay changeset is destroyed.  This
change will cause the final decrement be to zero.

After applying this patch, new validation warnings will be
reported from the devicetree unittest during boot due to
a pre-existing devicetree bug.  The warnings will be similar to:

  OF: ERROR: memory leak before free overlay changeset,  /testcase-data/overlay-node/test-bus/test-unittest4

This pre-existing devicetree bug will also trigger a WARN_ONCE() from
refcount_sub_and_test_checked() when an overlay changeset is
destroyed without having first been applied.  This scenario occurs
when an error in the overlay is detected during the overlay changeset
creation:

  WARNING: CPU: 0 PID: 1 at lib/refcount.c:187 refcount_sub_and_test_checked+0xa8/0xbc
  refcount_t: underflow; use-after-free.

  (unwind_backtrace) from (show_stack+0x10/0x14)
  (show_stack) from (dump_stack+0x6c/0x8c)
  (dump_stack) from (__warn+0xdc/0x104)
  (__warn) from (warn_slowpath_fmt+0x44/0x6c)
  (warn_slowpath_fmt) from (refcount_sub_and_test_checked+0xa8/0xbc)
  (refcount_sub_and_test_checked) from (kobject_put+0x24/0x208)
  (kobject_put) from (of_changeset_destroy+0x2c/0xb4)
  (of_changeset_destroy) from (free_overlay_changeset+0x1c/0x9c)
  (free_overlay_changeset) from (of_overlay_remove+0x284/0x2cc)
  (of_overlay_remove) from (of_unittest_apply_revert_overlay_check.constprop.4+0xf8/0x1e8)
  (of_unittest_apply_revert_overlay_check.constprop.4) from (of_unittest_overlay+0x960/0xed8)
  (of_unittest_overlay) from (of_unittest+0x1cc4/0x2138)
  (of_unittest) from (do_one_initcall+0x4c/0x28c)
  (do_one_initcall) from (kernel_init_freeable+0x29c/0x378)
  (kernel_init_freeable) from (kernel_init+0x8/0x110)
  (kernel_init) from (ret_from_fork+0x14/0x2c)

Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
2018-11-08 22:10:44 -08:00
..
unittest-data of/unittest: Fix I2C bus unit-address error 2018-09-19 15:10:06 -07:00
address.c drivers/of: Make of_io_request_and_map() "name" argument optional 2018-07-10 08:08:57 -06:00
base.c Devicetree fixes for v4.20-rc1: 2018-11-01 14:45:38 -07:00
device.c Devicetree updates for 4.20: 2018-10-26 12:09:58 -07:00
dynamic.c of: overlay: add tests to validate kfrees from overlay removal 2018-11-08 22:10:35 -08:00
fdt_address.c of: Use SPDX license tag for DT files 2018-01-08 08:22:45 -06:00
fdt.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
irq.c iommu/of: make of_pci_map_rid() available for other devices too 2018-09-25 09:47:52 +02:00
Kconfig of: change overlay apply input data from unflattened to FDT 2018-03-04 00:29:24 -08:00
kobj.c of: Use SPDX license tag for DT files 2018-01-08 08:22:45 -06:00
Makefile PCI: Move OF-related PCI functions into PCI core 2018-01-17 17:36:39 -06:00
of_mdio.c of: Convert to using %pOFn instead of device_node.name 2018-09-07 11:04:41 -05:00
of_net.c of_net: Implement of_get_nvmem_mac_address helper 2018-03-30 10:40:18 -04:00
of_numa.c of: use for_each_of_cpu_node iterator 2018-09-28 14:25:58 -05:00
of_private.h of: make default address and size cells sizes private 2018-09-07 11:04:41 -05:00
of_reserved_mem.c memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
overlay.c of: overlay: add missing of_node_put() after add new node to changeset 2018-11-08 22:10:44 -08:00
pdt.c of: Use SPDX license tag for DT files 2018-01-08 08:22:45 -06:00
platform.c Devicetree updates for 4.20: 2018-10-26 12:09:58 -07:00
property.c device property: Constify device_get_match_data() 2018-02-12 10:41:11 +01:00
resolver.c of: overlay: validate offset from property fixups 2018-05-23 15:07:43 -05:00
unittest.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00