Make the per_cpu(processors, cpu) entries available earlier so that they are available in arch_register_cpu() as ARM64 will need access to the acpi_handle to distinguish between acpi_processor_add() and earlier registration attempts (which will fail as _STA cannot be checked). Reorder the remove flow to clear this per_cpu() after arch_unregister_cpu() has completed, allowing it to be used in there as well. Note that on x86 for the CPU hotplug case, the pr->id prior to acpi_map_cpu() may be invalid. Thus the per_cpu() structures must be initialized after that call or after checking the ID is valid (not hotplug path). Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> --- v9: Add back a blank line accidentally removed in code move. Fix up error returns so that the new cleanup in processor_add() is triggered on detection of the bios bug. Combined with the previous 2 patches, should solve the leak that Gavin identified. --- drivers/acpi/acpi_processor.c | 80 +++++++++++++++++++++-------------- 1 file changed, 49 insertions(+), 31 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 16e36e55a560..4a79b42d649e 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -183,8 +183,38 @@ static void __init acpi_pcc_cpufreq_init(void) {} #endif /* CONFIG_X86 */ /* Initialization */ +static DEFINE_PER_CPU(void *, processor_device_array); + +static bool acpi_processor_set_per_cpu(struct acpi_processor *pr, + struct acpi_device *device) +{ + BUG_ON(pr->id >= nr_cpu_ids); + + /* + * Buggy BIOS check. + * ACPI id of processors can be reported wrongly by the BIOS. + * Don't trust it blindly + */ + if (per_cpu(processor_device_array, pr->id) != NULL && + per_cpu(processor_device_array, pr->id) != device) { + dev_warn(&device->dev, + "BIOS reported wrong ACPI id %d for the processor\n", + pr->id); + return false; + } + /* + * processor_device_array is not cleared on errors to allow buggy BIOS + * checks. + */ + per_cpu(processor_device_array, pr->id) = device; + per_cpu(processors, pr->id) = pr; + + return true; +} + #ifdef CONFIG_ACPI_HOTPLUG_CPU -static int acpi_processor_hotadd_init(struct acpi_processor *pr) +static int acpi_processor_hotadd_init(struct acpi_processor *pr, + struct acpi_device *device) { int ret; @@ -198,8 +228,16 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) if (ret) goto out; + if (!acpi_processor_set_per_cpu(pr, device)) { + ret = -EINVAL; + acpi_unmap_cpu(pr->id); + goto out; + } + ret = arch_register_cpu(pr->id); if (ret) { + /* Leave the processor device array in place to detect buggy bios */ + per_cpu(processors, pr->id) = NULL; acpi_unmap_cpu(pr->id); goto out; } @@ -217,7 +255,8 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) return ret; } #else -static inline int acpi_processor_hotadd_init(struct acpi_processor *pr) +static inline int acpi_processor_hotadd_init(struct acpi_processor *pr, + struct acpi_device *device) { return -ENODEV; } @@ -316,10 +355,13 @@ static int acpi_processor_get_info(struct acpi_device *device) * because cpuid <-> apicid mapping is persistent now. */ if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) { - int ret = acpi_processor_hotadd_init(pr); + int ret = acpi_processor_hotadd_init(pr, device); if (ret) return ret; + } else { + if (!acpi_processor_set_per_cpu(pr, device)) + return -EINVAL; } /* @@ -365,8 +407,6 @@ static int acpi_processor_get_info(struct acpi_device *device) * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. * Such things have to be put in and set up by the processor driver's .probe(). */ -static DEFINE_PER_CPU(void *, processor_device_array); - static int acpi_processor_add(struct acpi_device *device, const struct acpi_device_id *id) { @@ -395,28 +435,6 @@ static int acpi_processor_add(struct acpi_device *device, if (result) /* Processor is not physically present or unavailable */ goto err_clear_driver_data; - BUG_ON(pr->id >= nr_cpu_ids); - - /* - * Buggy BIOS check. - * ACPI id of processors can be reported wrongly by the BIOS. - * Don't trust it blindly - */ - if (per_cpu(processor_device_array, pr->id) != NULL && - per_cpu(processor_device_array, pr->id) != device) { - dev_warn(&device->dev, - "BIOS reported wrong ACPI id %d for the processor\n", - pr->id); - /* Give up, but do not abort the namespace scan. */ - goto err_clear_driver_data; - } - /* - * processor_device_array is not cleared on errors to allow buggy BIOS - * checks. - */ - per_cpu(processor_device_array, pr->id) = device; - per_cpu(processors, pr->id) = pr; - dev = get_cpu_device(pr->id); if (!dev) { result = -ENODEV; @@ -470,10 +488,6 @@ static void acpi_processor_remove(struct acpi_device *device) device_release_driver(pr->dev); acpi_unbind_one(pr->dev); - /* Clean up. */ - per_cpu(processor_device_array, pr->id) = NULL; - per_cpu(processors, pr->id) = NULL; - cpu_maps_update_begin(); cpus_write_lock(); @@ -481,6 +495,10 @@ static void acpi_processor_remove(struct acpi_device *device) arch_unregister_cpu(pr->id); acpi_unmap_cpu(pr->id); + /* Clean up. */ + per_cpu(processor_device_array, pr->id) = NULL; + per_cpu(processors, pr->id) = NULL; + cpus_write_unlock(); cpu_maps_update_done(); -- 2.39.2