There is no need to call spin_unlock_irqrestore() in every conditional
block, as release_nodes() can safely be called with an empty list, in
case we hit the "if else" or "else" case.
We do not use a scoped_guard() here to not unnecessarily change the
indentation level.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260202235210.55176-8-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently, there are three "subclasses" of struct devres_node, which are
struct devres, struct devres_group, struct devres_action.
release_nodes(), which only knows about the base struct devres_node,
assumes that for all "subclasses" struct devres_node is the first member
in the structure and calls kfree() on struct devres_node.
While this technically works, we can still improve semantical
correctness and type safety with a corresponding free_node() callback.
Additionally, we will need this callback soon in the Rust Devres code,
to allocate and free the required memory on the Rust side.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260202235210.55176-6-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently, devres actions are allocated with devres_alloc(), which
allocates a struct devres with a flexible array member for the actual
data of the resource. The flexible array member is aligned to
ARCH_DMA_MINALIGN, which is wasteful for devres actions that only need
to store a struct action_devres.
Introduce struct devres_action to handle devres actions separately from
struct devres, analogous to what we do for struct devres_group.
Speaking of which, without this patch struct devres_group is treated as
struct devres in release_nodes(). While this is not an actual bug, as
release callbacks for devres nodes in struct devres_group are empty
functions anyways, it is a bit messy and can be confusing.
(Note that besides devres actions, the Rust devres code will also make
use of this. The Rust compiler can figure out the correct alignment of T
in Devres<T> itself, i.e. no need to force a minimum alignment.)
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260202235210.55176-5-dakr@kernel.org
[ Add missing node->release check in devres_for_each_res() and
find_dr(); use kzalloc_obj(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Immutable tag for the driver core tree to pull from
devres: Move devm_*_action*() APIs to devres.h
devres: Add devm_is_action_added() helper
* tag 'gpiod-devm-is-action-added-for-v6.16-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
devres: Add devm_is_action_added() helper
devres: Move devm_*_action*() APIs to devres.h
When releasing a device, if the release action causes a group to be
released, a warning is emitted because it can't find the group. This
happens because devres_release_all() moves the entire list to a todo
list and also move the group markers. Considering r* normal resource
nodes and g1 a group resource node:
g1 -----------.
v v
r1 -> r2 -> g1[0] -> r3-> g[1] -> r4
After devres_release_all(), dev->devres_head becomes empty and the todo
list it iterates on becomes:
g1
v
r1 -> r2 -> r3-> r4 -> g1[0]
When a call to component_del() is made and takes down the aggregate
device, a warning like this happen:
RIP: 0010:devres_release_group+0x362/0x530
...
Call Trace:
<TASK>
component_unbind+0x156/0x380
component_unbind_all+0x1d0/0x270
mei_component_master_unbind+0x28/0x80 [mei_hdcp]
take_down_aggregate_device+0xc1/0x160
component_del+0x1c6/0x3e0
intel_hdcp_component_fini+0xf1/0x170 [xe]
xe_display_fini+0x1e/0x40 [xe]
Because the devres group corresponding to the hdcp component cannot be
found. Just ignore this corner case: if the dev->devres_head is empty
and the caller is trying to remove a group, it's likely in the process
of device cleanup so just ignore it instead of warning.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250222001051.3012936-2-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
devm_remove_action() warns if the action to remove does not exist
(anymore).
The Rust devres abstraction, however, has a use-case to call
devm_remove_action() at a point where it can't be guaranteed that the
corresponding action hasn't been released yet.
In particular, an instance of `Devres<T>` may be dropped after the
action has been released. So far, `Devres<T>` worked around this by
keeping the inner type alive.
Hence, add devm_remove_action_nowarn(), which returns an error code if
the action has been removed already.
A subsequent patch uses devm_remove_action_nowarn() to remove the action
when `Devres<T>` is dropped.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250107122609.8135-1-dakr@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
devm_free_percpu() calls devres_release() with a pointer in percpu
address space. devres_release() expects pointers in the generic address
space, so address space needs to be stripped from the argument.
When strict percpu address space checks are enabled, then the current
direct cast from the percpu address space to the generic address space
fails the compilation on x86_64 with:
devres.c:1234:32: error: cast to generic address space pointer from disjoint ‘__seg_gs’ address space pointer
Add intermediate casts to unsigned long to remove address space of
the pointer before casting it to the generic AS, as advised in [1]
and [2].
Side note: sparse still requires __force, although the documentation
[2] allows casts to unsigned long without __force attribute.
Found by GCC's named address space checks.
There were no changes in the resulting object file.
[1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html#x86-Named-Address-Spaces
[2] https://sparse.docs.kernel.org/en/latest/annotations.html#address-space-name
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20240830083406.9695-1-ubizjak@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Danilo Krummrich
Kees Cook
Andy ShevchenkoandDanilo Krummrich
Bartosz GolaszewskiandLinus Walleij
Greg Kroah-Hartman
Raag JadavandGreg Kroah-Hartman
Lucas De Marchi
Uros BizjakandGreg Kroah-Hartman
Zijun HuandGreg Kroah-Hartman