A comment in the review of the patch adding the phandle cache said that
the cache would have to be updated when modules are applied and removed.
This patch implements the cache updates.
Fixes: 0b3ce78e90 ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Reported-by: Alan Tull <atull@kernel.org>
Suggested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Only the overlay notifier callbacks have a chance to potentially get
hold of references to those two resources, but they are not supposed to
store them beyond OF_OVERLAY_POST_REMOVE.
Document the overlay notifier API, its constraint regarding pointer
lifetime, and then remove intentional leaks of ovcs->overlay_tree and
ovcs->fdt from free_overlay_changeset.
See also https://lkml.org/lkml/2018/4/23/1063 and following.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
While technically the ovcs_id is still returned by of_overlay_apply(),
this is an internal function. All public callers of of_overlay_remove()
pass an ovcs_id returned by the public function of_overlay_fdt_apply().
Fixes: 39a751a4cb ("of: change overlay apply input data from unflattened to FDT")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>
Struct device_node full_name no longer includes the full path name
when the devicetree is created from a flattened device tree (FDT).
The overlay node creation code was not modified to reflect this
change. Fix the node full_name generated by overlay code to contain
only the basename.
Unittests call an overlay internal function to create new nodes.
Fix up these calls to provide basename only instead of the full
path.
Fixes: a7e4cfb0a7 ("of/fdt: only store the device node basename
in full_name")
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Errors while developing the patch to create of_overlay_fdt_apply()
exposed inadequate error messages to debug problems when overlay
devicetree fragment nodes contain an invalid target path. Improve
the messages in find_target_node() to remedy this.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
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 <frank.rowand@sony.com>
Make it more clear that nodes without "__overlay__" subnodes are
skipped, by reverting the logic and using continue.
This also reduces indentation level.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>
If an overlay has no "__symbols__" node, but it has nodes without
"__overlay__" subnodes at the end (e.g. a "__fixups__" node), after
filling in all fragments for nodes with "__overlay__" subnodes,
"fragment = &fragments[cnt]" will point beyond the end of the allocated
array.
Hence writing to "fragment->overlay" will overwrite unallocated memory,
which may lead to a crash later.
Fix this by deferring both the assignment to "fragment" and the
offending write afterwards until we know for sure the node has an
"__overlay__" subnode, and thus a valid entry in "fragments[]".
Fixes: 61b4de4e0b ("of: overlay: minor restructuring")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>
The special overlay mutex is taken first, hence it should be released
last in the error path.
of_resolve_phandles() must be called with of_mutex held. Without it, a
node and new phandle could be added via of_attach_node(), making the max
phandle wrong.
free_overlay_changeset() must be called with of_mutex held, if any
non-trivial cleanup is to be done.
Hence move "mutex_lock(&of_mutex)" up, as suggested by Frank, and merge
the two tail statements of the success and error paths, now they became
identical.
Note that while the two mutexes are adjacent, we still need both:
__of_changeset_apply_notify(), which is called by __of_changeset_apply()
unlocks of_mutex, then does notifications then locks of_mutex. So the
mutex get released in the middle of of_overlay_apply()
Fixes: f948d6d8b7 ("of: overlay: avoid race condition between applying multiple overlays")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
If of_resolve_phandles() fails, free_overlay_changeset() is called in
the error path. However, that function returns early if the list hasn't
been initialized yet, before freeing the object.
Explicitly calling kfree() instead would solve that issue. However, that
complicates matter, by having to consider which of two different methods
to use to dispose of the same object.
Hence make free_overlay_changeset() consider initialization state of the
different parts of the object, making it always safe to call (once!) to
dispose of a (partially) initialized overlay_changeset:
- Only destroy the changeset if the list was initialized,
- Make init_overlay_changeset() store the ID in ovcs->id on success,
to avoid calling idr_remove() with an error value or an already
released ID.
Reported-by: Colin King <colin.king@canonical.com>
Fixes: f948d6d8b7 ("of: overlay: avoid race condition between applying multiple overlays")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
If an "if" branch is terminated by a "goto", there's no need to have an
"else" statement and an indented block of code.
Remove the "else" statement to simplify the code flow for the casual
reviewer.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>
The same error string occurs in drivers/of/resolver.c. Change
the error here to more precisely describe this case, and avoid
the possible confusion of looking in the wrong source location
to understand the cause of an error.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
A device tree overlay notifier can return NOTIFY_OK, NOTIFY_STOP,
or an embedded errno. overlay_notify() incorrectly reports an
error for NOTIFY_OK.
Reported-by: atull@kernel.org
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
kbasename() will not return NULL if passed a valid string. If
the parameter passed to kbasename() in this case is already NULL
then the devicetree has been corrupted.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
The "%pOF" printf format was recently added to print the
full name of a device tree node, with the intent of changing
the node full_name field to contain only the node name instead
of the full path of the node.
dup_and_fixup_symbol_prop() duplicates a property from the
"/__symbols__" node of an overlay device tree. The value
of each duplicated property must be fixed up to include
the full path of a node in the live device tree. The
current code uses the node's full_name for that purpose.
Update the code to use the "%pOF" printf format to
determine the node's full path.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
The code to apply symbols from an overlay to the live device tree
was implemented with the intent to be minimally intrusive on the
existing code. After recent restructuring of the overlay apply
code, it is easier to disintangle the code that applies the
symbols, and to make the overlay changeset creation code more
straight forward and understandable.
Remove the extra complexity, and make the code more obvious.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
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 <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
When an overlay contains a node that already exists in
the live device tree, the overlay node is not allowed
to change the phandle of the existing node.
The existing check refused to allow an overlay node to
set the node phandle even when the existing node did
not have a phandle. Relax the check to allow an
overlay node to set the phandle value if the existing
node does not have a phandle.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
The test of whether it is safe to remove an overlay changeset
looked at whether any node in the overlay changeset was in a
subtree rooted at any more recently applied overlay changeset
node.
The test failed to determine whether any node in the overlay
changeset was the root of a subtree that contained a more
recently applied overlay changeset node. Add this additional
check to the test.
The test is still lacking any check for any phandle dependencies.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
When an attempt to apply an overlay changeset fails, an effort
is made to revert any partial application of the changeset.
When an attempt to remove an overlay changeset fails, an effort
is made to re-apply any partial reversion of the changeset.
The existing code does not check for failure to recover a failed
overlay changeset application or overlay changeset revert.
Add the missing checks and flag the devicetree as corrupt if the
state of the devicetree can not be determined.
Improve and expand the returned errors to more fully reflect the
result of the effort to undo the partial effects of a failed attempt
to apply or remove an overlay changeset.
If the device tree might be corrupt, do not allow further attempts
to apply or remove an overlay changeset.
When creating an overlay changeset from an overlay device tree,
add some additional warnings if the state of the overlay device
tree is not as expected.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Continue improving the readability of overlay.c. The previous patches
renamed identifiers. This patch is split out from the previous patches
to make the previous patches easier to review.
Changes are:
- minor code restructuring
- some initialization of an overlay changeset occurred outside of
init_overlay_changeset(), move that into init_overlay_changeset()
- consolidate freeing an overlay changeset into free_overlay_changeset()
This patch is intended to not introduce any functional change.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
More renaming of identifiers to better reflect what they do.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Rob Herring
Frank Rowand
Jan Kiszka
Geert Uytterhoeven