On Mon, Feb 6, 2017 at 6:01 PM, Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote:
> We may or may not have all possible CPUs in MADT on boot but in any case
> we're overwriting x86_cpu_to_acpiid mapping with U32_MAX when
> acpi_register_lapic() is called again on the CPU hotplug path:
> acpi_processor_hotadd_init() -> acpi_map_cpu() -> acpi_register_lapic().
>
> As we have the required acpi_id information in acpi_processor_hotadd_init()
> propagate it to acpi_map_cpu() to always keep x86_cpu_to_acpiid mapping
> valid.
>
> Reported-by: Andrew Jones <drjones@xxxxxxxxxx>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Is the bug report available and if so, do you have a pointer to it?
> ---
> arch/ia64/kernel/acpi.c | 3 ++-
> arch/x86/kernel/acpi/boot.c | 5 +++--
> drivers/acpi/acpi_processor.c | 4 ++--
> include/linux/acpi.h | 3 ++-
> 4 files changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
> index 9273e03..7508c30 100644
> --- a/arch/ia64/kernel/acpi.c
> +++ b/arch/ia64/kernel/acpi.c
> @@ -887,7 +887,8 @@ static int _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
> }
>
> /* wrapper to silence section mismatch warning */
> -int __ref acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu)
> +int __ref acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id,
> + int *pcpu)
> {
> return _acpi_map_lsapic(handle, physid, pcpu);
> }
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 64422f8..04bc5f3 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -723,11 +723,12 @@ int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
> return 0;
> }
>
> -int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu)
> +int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id,
> + int *pcpu)
> {
> int cpu;
>
> - cpu = acpi_register_lapic(physid, U32_MAX, ACPI_MADT_ENABLED);
> + cpu = acpi_register_lapic(physid, acpi_id, ACPI_MADT_ENABLED);
> if (cpu < 0) {
> pr_info(PREFIX "Unable to map lapic to logical cpu number\n");
> return cpu;
> diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
> index 3de3b6b..4467a80 100644
> --- a/drivers/acpi/acpi_processor.c
> +++ b/drivers/acpi/acpi_processor.c
> @@ -165,7 +165,7 @@ static int acpi_processor_errata(void)
>
> #ifdef CONFIG_ACPI_HOTPLUG_CPU
> int __weak acpi_map_cpu(acpi_handle handle,
> - phys_cpuid_t physid, int *pcpu)
> + phys_cpuid_t physid, u32 acpi_id, int *pcpu)
> {
> return -ENODEV;
> }
> @@ -203,7 +203,7 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr)
> cpu_maps_update_begin();
> cpu_hotplug_begin();
>
> - ret = acpi_map_cpu(pr->handle, pr->phys_id, &pr->id);
> + ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id);
> if (ret)
> goto out;
>
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 5b36974..6ab47e9 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -291,7 +291,8 @@ bool acpi_processor_validate_proc_id(int proc_id);
>
> #ifdef CONFIG_ACPI_HOTPLUG_CPU
> /* Arch dependent functions for cpu hotplug support */
> -int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu);
> +int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id,
> + int *pcpu);
> int acpi_unmap_cpu(int cpu);
> int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid);
> #endif /* CONFIG_ACPI_HOTPLUG_CPU */
> --
Thanks,
Rafael
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