Tested-by: David Saggiorato <david@xxxxxxxxxxxxxx>Le mercredi 28 septembre 2016 à 16:06 -0700, Andy Lutomirski a écrit :
> Otherwise arch_task_struct_size == 0 and we die. While we're at it,
> set X86_FEATURE_ALWAYS, too.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Dave Hansen <dave@xxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce
> CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86")
> Reported-by: david@xxxxxxxxxxxxxx
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
> ---
>
> Totally untested except by the 0-day bot, since I don't have an
> affected machine and QEMU can't emulate anything without CPUID.
>
> arch/x86/kernel/cpu/common.c | 23 +++++++++++------------
> 1 file changed, 11 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/common.c
> b/arch/x86/kernel/cpu/common.c
> index 809eda03c527..bcc9ccc220c9 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -804,21 +804,20 @@ static void __init early_identify_cpu(struct
> cpuinfo_x86 *c)
> identify_cpu_without_cpuid(c);
>
> /* cyrix could have cpuid enabled via c_identify()*/
> - if (!have_cpuid_p())
> - return;
> + if (have_cpuid_p()) {
> + cpu_detect(c);
> + get_cpu_vendor(c);
> + get_cpu_cap(c);
>
> - cpu_detect(c);
> - get_cpu_vendor(c);
> - get_cpu_cap(c);
> -
> - if (this_cpu->c_early_init)
> - this_cpu->c_early_init(c);
> + if (this_cpu->c_early_init)
> + this_cpu->c_early_init(c);
>
> - c->cpu_index = 0;
> - filter_cpuid_features(c, false);
> + c->cpu_index = 0;
> + filter_cpuid_features(c, false);
>
> - if (this_cpu->c_bsp_init)
> - this_cpu->c_bsp_init(c);
> + if (this_cpu->c_bsp_init)
> + this_cpu->c_bsp_init(c);
> + }
>
> setup_force_cpu_cap(X86_FEATURE_ALWAYS);
> fpu__init_system(c);Attachment:
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