kernel/linux.git/drivers/acpi/acpi_processor.c, branch v6.6.132

ACPI: processor: Fix previous acpi_processor_errata_piix4() fix

2026-03-25T10:06:08+00:00

[ Upstream commit bf504b229cb8d534eccbaeaa23eba34c05131e25 ] After commi f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()"), device pointers may be dereferenced after dropping references to the device objects pointed to by them, which may cause a use-after-free to occur. Moreover, debug messages about enabling the errata may be printed if the errata flags corresponding to them are unset. Address all of these issues by moving message printing to the points in the code where the errata flags are set. Fixes: f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()") Reported-by: Guenter Roeck Closes: https://lore.kernel.org/linux-acpi/938e2206-def5-4b7a-9b2c-d1fd37681d8a@roeck-us.net/ Reviewed-by: Guenter Roeck Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/5975693.DvuYhMxLoT@rafael.j.wysocki Signed-off-by: Sasha Levin

ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()

2026-03-04T12:20:34+00:00

[ Upstream commit f132e089fe89cadc2098991f0a3cb05c3f824ac6 ] In acpi_processor_errata_piix4(), the pointer dev is first assigned an IDE device and then reassigned an ISA device: dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB, ...); dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB_0, ...); If the first lookup succeeds but the second fails, dev becomes NULL. This leads to a potential null-pointer dereference when dev_dbg() is called: if (errata.piix4.bmisx) dev_dbg(&dev->dev, ...); To prevent this, use two temporary pointers and retrieve each device independently, avoiding overwriting dev with a possible NULL value. Signed-off-by: Tuo Li [ rjw: Subject adjustment, added an empty code line ] Link: https://patch.msgid.link/20260111163214.202262-1-islituo@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: processor: fix acpi_object initialization

2025-08-28T14:28:17+00:00

[ Upstream commit 13edf7539211d8f7d0068ce3ed143005f1da3547 ] Initialization of the local acpi_object in acpi_processor_get_info() only sets the first 4 bytes to zero and is thus incomplete. This is indicated by messages like: acpi ACPI0007:be: Invalid PBLK length [166288104] Fix this by initializing all 16 bytes of the processor member of that union. Signed-off-by: Sebastian Ott Link: https://patch.msgid.link/20250703124215.12522-1-sebott@redhat.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: processor: Fix memory leaks in error paths of processor_add()

2024-09-12T09:11:42+00:00

[ Upstream commit 47ec9b417ed9b6b8ec2a941cd84d9de62adc358a ] If acpi_processor_get_info() returned an error, pr and the associated pr->throttling.shared_cpu_map were leaked. The unwind code was in the wrong order wrt to setup, relying on some unwind actions having no affect (clearing variables that were never set etc). That makes it harder to reason about so reorder and add appropriate labels to only undo what was actually set up in the first place. Acked-by: Rafael J. Wysocki Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-6-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

ACPI: processor: Return an error if acpi_processor_get_info() fails in processor_add()

2024-09-12T09:11:42+00:00

[ Upstream commit fadf231f0a06a6748a7fc4a2c29ac9ef7bca6bfd ] Rafael observed [1] that returning 0 from processor_add() will result in acpi_default_enumeration() being called which will attempt to create a platform device, but that makes little sense when the processor is known to be not available. So just return the error code from acpi_processor_get_info() instead. Link: https://lore.kernel.org/all/CAJZ5v0iKU8ra9jR+EmgxbuNm=Uwx2m1-8vn_RAZ+aCiUVLe3Pw@mail.gmail.com/ [1] Suggested-by: Rafael J. Wysocki Acked-by: Rafael J. Wysocki Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-5-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

cpu-hotplug: Provide prototypes for arch CPU registration

2023-10-11T12:27:37+00:00

Provide common prototypes for arch_register_cpu() and arch_unregister_cpu(). These are called by acpi_processor.c, with weak versions, so the prototype for this is already set. It is generally not necessary for function prototypes to be conditional on preprocessor macros. Some architectures (e.g. Loongarch) are missing the prototype for this, and rather than add it to Loongarch's asm/cpu.h, do the job once for everyone. Since this covers everyone, remove the now unnecessary prototypes in asm/cpu.h, and therefore remove the 'static' from one of ia64's arch_register_cpu() definitions. [ tglx: Bring back the ia64 part and remove the ACPI prototypes ] Signed-off-by: Russell King (Oracle) Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/E1qkoRr-0088Q8-Da@rmk-PC.armlinux.org.uk

ACPI: processor: Refine messages in acpi_early_processor_control_setup()

2023-07-20T19:05:00+00:00

The source and meaning of the messages printed by acpi_early_processor_control_setup() is unclear, so add a pr_fmt() definition to acpi_processor.c and expand the messages to make it clear that they are about CPUs. Signed-off-by: Rafael J. Wysocki Reviewed-by: Michal Wilczynski

ACPI: processor: Remove acpi_hwp_native_thermal_lvt_osc()

2023-07-17T12:47:42+00:00

The workaround for buggy skylake BIOSes is now implemented in acpi_processor_osc() and acpi_hwp_native_thermal_lvt_osc() has no callers, so drop it. Suggested-by: Rafael J. Wysocki Signed-off-by: Michal Wilczynski Reviewed-by: Andy Shevchenko [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

ACPI: processor: Use _OSC to convey OSPM processor support information

2023-07-17T12:47:18+00:00

Change acpi_early_processor_osc() to return a value in case of a failure and make it static. Also make it run acpi_processor_osc() for every processor object or processor device found in the ACPI Namespace (previously, its only purpose was to work around platform firmware defects on Skylake systems). Introduce a new function called acpi_early_processor_control_setup() that will invoke acpi_early_processor_osc() first in order to convey the OS processor support information to the platform firmware and if that fails, it will fall back to using _PDC. Suggested-by: Rafael J. Wysocki Signed-off-by: Michal Wilczynski Reviewed-by: Andy Shevchenko [ rjw: Subject and changelog edits, change function return value to bool, add missing 'static', change messages ] Signed-off-by: Rafael J. Wysocki

ACPI: processor: Introduce acpi_processor_osc()

2023-07-14T15:59:40+00:00

The processor _OSC method is already used for a workaround introduced in commit a21211672c9a ("ACPI / processor: Request native thermal interrupt handling via _OSC"), but in accordance with ACPI 6.5 (and earlier), it should be used for negotiating all of the processor capabilities instead of _PDC (which has been deprecated since ACPI 3.0 and got removed from ACPI 6.5 entirely). Create a new callback function called acpi_processor_osc() to be invoked for every processor object and processor device in the ACPI namespace, in analogy with the already existing acpi_hwp_native_thermal_lvt_osc(). Make this function implement the workaround mentioned above and convey all of the OSPM processor support information to the platform firmware by setting all of the appropriate processor capabilities bits before evaluating _OSC for the given processor. For this purpose, make it call arch_acpi_set_proc_cap_bits() and modify the latter to set ACPI_PROC_CAP_COLLAB_PROC_PERF along with the other processor capabilities bits. Suggested-by: Rafael J. Wysocki Signed-off-by: Michal Wilczynski Reviewed-by: Andy Shevchenko [ rjw: Subject and changelog edits, whitespace fixup ] Signed-off-by: Rafael J. Wysocki