kernel/linux.git/drivers/acpi/ec.c, branch v7.0-rc7

ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()

2026-03-24T17:47:10+00:00

When ec_install_handlers() returns -EPROBE_DEFER on reduced-hardware platforms, it has already started the EC and installed the address space handler with the struct acpi_ec pointer as handler context. However, acpi_ec_setup() propagates the error without any cleanup. The caller acpi_ec_add() then frees the struct acpi_ec for non-boot instances, leaving a dangling handler context in ACPICA. Any subsequent AML evaluation that accesses an EC OpRegion field dispatches into acpi_ec_space_handler() with the freed pointer, causing a use-after-free: BUG: KASAN: slab-use-after-free in mutex_lock (kernel/locking/mutex.c:289) Write of size 8 at addr ffff88800721de38 by task init/1 Call Trace: mutex_lock (kernel/locking/mutex.c:289) acpi_ec_space_handler (drivers/acpi/ec.c:1362) acpi_ev_address_space_dispatch (drivers/acpi/acpica/evregion.c:293) acpi_ex_access_region (drivers/acpi/acpica/exfldio.c:246) acpi_ex_field_datum_io (drivers/acpi/acpica/exfldio.c:509) acpi_ex_extract_from_field (drivers/acpi/acpica/exfldio.c:700) acpi_ex_read_data_from_field (drivers/acpi/acpica/exfield.c:327) acpi_ex_resolve_node_to_value (drivers/acpi/acpica/exresolv.c:392) Allocated by task 1: acpi_ec_alloc (drivers/acpi/ec.c:1424) acpi_ec_add (drivers/acpi/ec.c:1692) Freed by task 1: kfree (mm/slub.c:6876) acpi_ec_add (drivers/acpi/ec.c:1751) The bug triggers on reduced-hardware EC platforms (ec->gpe < 0) when the GPIO IRQ provider defers probing. Once the stale handler exists, any unprivileged sysfs read that causes AML to touch an EC OpRegion (battery, thermal, backlight) exercises the dangling pointer. Fix this by calling ec_remove_handlers() in the error path of acpi_ec_setup() before clearing first_ec. ec_remove_handlers() checks each EC_FLAGS_* bit before acting, so it is safe to call regardless of how far ec_install_handlers() progressed: -ENODEV (handler not installed): only calls acpi_ec_stop() -EPROBE_DEFER (handler installed): removes handler, stops EC Fixes: 03e9a0e05739 ("ACPI: EC: Consolidate event handler installation code") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Link: https://patch.msgid.link/20260324165458.1337233-2-bestswngs@gmail.com Signed-off-by: Rafael J. Wysocki

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

ACPI: driver: Drop driver_data pointer clearing from two drivers

2026-02-13T21:19:14+00:00

It is not necessary to clear the driver_data pointer in the ACPI companion device object on driver remove in the EC and SMBUS HC ACPI drivers because that pointer is not used there any more after recent changes. Drop the unnecessary statements. Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/6242843.lOV4Wx5bFT@rafael.j.wysocki

ACPI: SMBUS HC: Convert the driver to a platform one

2025-12-29T20:04:23+00:00

While binding drivers directly to struct acpi_device objects allows basic functionality to be provided, at least in the majority of cases, there are some problems with it, related to general consistency, sysfs layout, power management operation ordering, and code cleanliness. Overall, it is better to bind drivers to platform devices than to their ACPI companions, so convert the ACPI SMBUS HC driver to a platform one. After this conversion, acpi_ec_probe() does not need to populate the driver_data pointer of the EC platform device's ACPI companion any more, so update it accordingly. While this is not expected to alter functionality, it changes sysfs layout and so it will be visible to user space. Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/13909645.uLZWGnKmhe@rafael.j.wysocki

ACPI: EC: Convert the driver to a platform one

2025-12-29T20:04:23+00:00

While binding drivers directly to struct acpi_device objects allows basic functionality to be provided, at least in the majority of cases, there are some problems with it, related to general consistency, sysfs layout, power management operation ordering, and code cleanliness. Overall, it is better to bind drivers to platform devices than to their ACPI companions, so convert the ACPI embedded controller (EC) driver to a platform one. After this conversion, acpi_bus_register_early_device() does not need to attempt to bind an ACPI driver to the struct acpi_device created by it, so update it accordingly. While this is not expected to alter functionality, it changes sysfs layout and so it will be visible to user space. Signed-off-by: Rafael J. Wysocki [ rjw: Removed excess semicolon ] Link: https://patch.msgid.link/1946304.tdWV9SEqCh@rafael.j.wysocki Signed-off-by: Rafael J. Wysocki

ACPI: EC: Add WQ_PERCPU to alloc_workqueue() users

2025-11-03T17:45:42+00:00

Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistentcy cannot be addressed without refactoring the API. alloc_workqueue() treats all queues as per-CPU by default, while unbound workqueues must opt-in via WQ_UNBOUND. This default is suboptimal: most workloads benefit from unbound queues, allowing the scheduler to place worker threads where they’re needed and reducing noise when CPUs are isolated. This change adds a new WQ_PERCPU flag to explicitly request alloc_workqueue() to be per-cpu when WQ_UNBOUND has not been specified. With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND must now use WQ_PERCPU. Once migration is complete, WQ_UNBOUND can be removed and unbound will become the implicit default. Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari [ rjw: Subject adjustment ] Link: https://patch.msgid.link/20251030154739.262582-4-marco.crivellari@suse.com Signed-off-by: Rafael J. Wysocki

ACPI: EC: Relax sanity check of the ECDT ID string

2025-08-12T17:16:27+00:00

It turns out that the ECDT table inside the ThinkBook 14 G7 IML contains a valid EC description but an invalid ID string ("_SB.PC00.LPCB.EC0"). Ignoring this ECDT based on the invalid ID string prevents the kernel from detecting the built-in touchpad, so relax the sanity check of the ID string and only reject ECDTs with empty ID strings. Reported-by: Ilya K Fixes: 7a0d59f6a913 ("ACPI: EC: Ignore ECDT tables with an invalid ID string") Signed-off-by: Armin Wolf Tested-by: Ilya K Link: https://patch.msgid.link/20250729062038.303734-1-W_Armin@gmx.de Cc: 6.16+ # 6.16+ Signed-off-by: Rafael J. Wysocki

ACPI: EC: Ignore ECDT tables with an invalid ID string

2025-06-10T18:55:31+00:00

On the MSI Modern 14 C5M the ECDT table contains invalid data: UID : 00000000 GPE Number : 00 /* Invalid, 03 would be correct */ Namepath : "" /* Invalid, "\_SB.PCI0.SBRG.EC" would * be correct */ This slows down the EC access as the wrong GPE event is used for communication. Additionally the ID string is invalid. Ignore such faulty ECDT tables by verifying that the ID string has a valid format. Tested-by: glpnk@proton.me Signed-off-by: Armin Wolf Link: https://patch.msgid.link/20250529235310.540530-1-W_Armin@gmx.de Signed-off-by: Rafael J. Wysocki

ACPI: EC: Add device to acpi_ec_no_wakeup[] qurik list

2025-05-09T19:20:03+00:00

Add the TUXEDO InfinityBook Pro AMD Gen9 to the acpi_ec_no_wakeup[] quirk list to prevent spurious wakeups. Signed-off-by: Werner Sembach Link: https://patch.msgid.link/20250508111625.12149-1-wse@tuxedocomputers.com Signed-off-by: Rafael J. Wysocki