linux-toradex.git/drivers/of/overlay.c, branch v5.19

of: overlay: do not free changeset when of_overlay_apply returns error

2022-05-03T16:53:15+00:00

New unittests for overlay notifiers reveal a memory leak in
of_overlay_apply() when a notifier returns an error for action
OF_OVERLAY_POST_APPLY.  The pr_err() message is:

   OF: ERROR: memory leak, expected refcount 1 instead of 3,
   of_node_get()/of_node_put() unbalanced - destroy cset entry: attach
   overlay node /testcase-data/overlay-node/test-bus/test-unittest17

Change the error path to no longer call free_overlay_changeset(),
and document that the caller of of_overlay_fdt_apply() may choose
to remove the overlay.

Update the unittest that triggered the error to expect the changed
return values and to call of_overlay_remove().

Signed-off-by: Frank Rowand 
Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20220502181742.1402826-4-frowand.list@gmail.com

of: overlay: add entry to of_overlay_action_name[]

2022-05-03T16:53:15+00:00

The values of enum of_overlay_notify_action are used to index into
array of_overlay_action_name.  Add an entry to of_overlay_action_name
for the value recently added to of_overlay_notify_action.

Array of_overlay_action_name[] is moved into include/linux/of.h
adjacent to enum of_overlay_notify_action to make the connection
between the two more obvious if either is modified in the future.

The only use of of_overlay_action_name is for error reporting in
overlay_notify().  All callers of overlay_notify() report the same
error, but with fewer details.  Remove the redundant error reports
in the callers.

Fixes: 067c098766c6 ("of: overlay: rework overlay apply and remove kfree()s")
Reported-by: Dan Carpenter 
Signed-off-by: Frank Rowand 
Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20220502181742.1402826-2-frowand.list@gmail.com

of: overlay: rework overlay apply and remove kfree()s

2022-04-25T15:56:11+00:00

Fix various kfree() issues related to of_overlay_apply().
  - Double kfree() of fdt and tree when init_overlay_changeset()
    returns an error.
  - free_overlay_changeset() free the root of the unflattened
    overlay (variable tree) instead of the memory that contains
    the unflattened overlay.
  - For the case of a failure during applying an overlay, move kfree()
    of new_fdt and overlay_mem into free_overlay_changeset(), which
    is called by the function that allocated them.
  - For the case of removing an overlay, the kfree() of new_fdt and
    overlay_mem remains in free_overlay_changeset().
  - Check return value of of_fdt_unflatten_tree() for error instead
    of checking the returned value of overlay_root.
  - When storing pointers to allocated objects in ovcs, do so as
    near to the allocation as possible instead of in deeply layered
    function.

More clearly document policy related to lifetime of pointers into
overlay memory.

Double kfree()
Reported-by: Slawomir Stepien 

Signed-off-by: Frank Rowand 
Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20220420222505.928492-3-frowand.list@gmail.com

of: overlay: rename variables to be consistent

2022-04-25T15:56:01+00:00

Variables change name across function calls when there is not a good
reason to do so.  Fix by changing "fdt" to "new_fdt" and "tree" to
"overlay_root".

The name disparity was confusing when creating the following commit.
The name changes are in this separate commit to make review of the
following commmit less complex.

Signed-off-by: Frank Rowand 
Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20220420222505.928492-2-frowand.list@gmail.com

of: overlay: do not break notify on NOTIFY_{OK|STOP}

2022-04-25T13:50:54+00:00

We should not break overlay notifications on NOTIFY_{OK|STOP}
otherwise we might break on the first fragment. We should only stop
notifications if a *real* errno is returned by one of the listeners.

Fixes: a1d19bd4cf1fe ("of: overlay: pr_err from return NOTIFY_OK to overlay apply/remove")
Signed-off-by: Nuno Sá 
Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20220420130205.89435-1-nuno.sa@analog.com

of: overlay: Remove redundant assignment to ret

2021-05-03T18:57:56+00:00

Variable ret is set to zero but this value is never read as it is
overwritten with a new value later on, hence it is a redundant
assignment and can be removed.

Cleans up the following clang-analyzer warning:

drivers/of/overlay.c:1197:2: warning: Value stored to 'ret' is never
read [clang-analyzer-deadcode.DeadStores].

drivers/of/overlay.c:1026:2: warning: Value stored to 'ret' is never
read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot 
Signed-off-by: Jiapeng Chong 
Link: https://lore.kernel.org/r/1619347258-55002-1-git-send-email-jiapeng.chong@linux.alibaba.com
Signed-off-by: Rob Herring

Merge tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

2021-04-28T22:50:24+00:00

Pull devicetree updates from Rob Herring:

 - Refactor powerpc and arm64 kexec DT handling to common code. This
   enables IMA on arm64.

 - Add kbuild support for applying DT overlays at build time. The first
   user are the DT unittests.

 - Fix kerneldoc formatting and W=1 warnings in drivers/of/

 - Fix handling 64-bit flag on PCI resources

 - Bump dtschema version required to v2021.2.1

 - Enable undocumented compatible checks for dtbs_check. This allows
   tracking of missing binding schemas.

 - DT docs improvements. Regroup the DT docs and add the example schema
   and DT kernel ABI docs to the doc build.

 - Convert Broadcom Bluetooth and video-mux bindings to schema

 - Add QCom sm8250 Venus video codec binding schema

 - Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile
   Technologies Inc.

 - Cleanup of DT schema type references on common properties and
   standard unit properties

* tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (64 commits)
  powerpc: If kexec_build_elf_info() fails return immediately from elf64_load()
  powerpc: Free fdt on error in elf64_load()
  of: overlay: Fix kerneldoc warning in of_overlay_remove()
  of: linux/of.h: fix kernel-doc warnings
  of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses
  dt-bindings: bcm4329-fmac: add optional brcm,ccode-map
  docs: dt: update writing-schema.rst references
  dt-bindings: media: venus: Add sm8250 dt schema
  of: base: Fix spelling issue with function param 'prop'
  docs: dt: Add DT API documentation
  of: Add missing 'Return' section in kerneldoc comments
  of: Fix kerneldoc output formatting
  docs: dt: Group DT docs into relevant sub-sections
  docs: dt: Make 'Devicetree' wording more consistent
  docs: dt: writing-schema: Include the example schema in the doc build
  docs: dt: writing-schema: Remove spurious indentation
  dt-bindings: Fix reference in submitting-patches.rst to the DT ABI doc
  dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3
  dt-bindings: media: video-interfaces: Drop the example
  devicetree: bindings: clock: Minor typo fix in the file armada3700-tbg-clock.txt
  ...

of: overlay: Fix kerneldoc warning in of_overlay_remove()

2021-04-21T21:05:53+00:00

'*ovcs_id' causes a warning because '*' is treated as bold markup:

Documentation/devicetree/kernel-api:56: ../drivers/of/overlay.c:1184: WARNING: Inline emphasis start-string without end-string.

Fix this by using the normal '@' markup for function parameters. That
appears to be enough to keep the '*' from being interpretted as markup.

Reported-by: Stephen Rothwell 
Cc: Frank Rowand 
Link: https://lore.kernel.org/r/20210421154548.1192903-1-robh@kernel.org/
Signed-off-by: Rob Herring

of: unittest: overlay: ensure proper alignment of copied FDT

2021-04-08T21:38:47+00:00

The Devicetree standard specifies an 8 byte alignment of the FDT.
Code in libfdt expects this alignment for an FDT image in memory.
kmemdup() returns 4 byte alignment on openrisc.  Replace kmemdup()
with kmalloc(), align pointer, memcpy() to get proper alignment.

The 4 byte alignment exposed a related bug which triggered a crash
on openrisc with:
commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
as reported in:
https://lore.kernel.org/lkml/20210327224116.69309-1-linux@roeck-us.net/

Reported-by: Guenter Roeck 
Signed-off-by: Frank Rowand 
Link: https://lore.kernel.org/r/20210408204508.2276230-1-frowand.list@gmail.com
Signed-off-by: Rob Herring

of: properly check for error returned by fdt_get_name()

2021-04-07T18:07:30+00:00

fdt_get_name() returns error values via a parameter pointer
instead of in function return.  Fix check for this error value
in populate_node() and callers of populate_node().

Chasing up the caller tree showed callers of various functions
failing to initialize the value of pointer parameters that
can return error values.  Initialize those values to NULL.

The bug was introduced by
commit e6a6928c3ea1 ("of/fdt: Convert FDT functions to use libfdt")
but this patch can not be backported directly to that commit
because the relevant code has further been restructured by
commit dfbd4c6eff35 ("drivers/of: Split unflatten_dt_node()")

The bug became visible by triggering a crash on openrisc with:
commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
as reported in:
https://lore.kernel.org/lkml/20210327224116.69309-1-linux@roeck-us.net/

Fixes: 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
Reported-by: Guenter Roeck 
Signed-off-by: Frank Rowand 
Tested-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20210405032845.1942533-1-frowand.list@gmail.com
Signed-off-by: Rob Herring