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    Subject[PATCH 9/9] x86/entry, cpumask: Provide non-instrumented variant of cpu_is_offline()
    vmlinux.o: warning: objtool: exc_nmi()+0x12: call to cpumask_test_cpu.constprop.0() leaves .noinstr.text section
    vmlinux.o: warning: objtool: mce_check_crashing_cpu()+0x12: call to cpumask_test_cpu.constprop.0()leaves .noinstr.text section

    cpumask_test_cpu()
    test_bit()
    instrument_atomic_read()
    arch_test_bit()

    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    ---
    arch/x86/kernel/cpu/mce/core.c | 2 +-
    arch/x86/kernel/nmi.c | 2 +-
    include/linux/cpumask.h | 15 ++++++++++++++-
    3 files changed, 16 insertions(+), 3 deletions(-)

    --- a/arch/x86/kernel/cpu/mce/core.c
    +++ b/arch/x86/kernel/cpu/mce/core.c
    @@ -1083,7 +1083,7 @@ static noinstr bool mce_check_crashing_c
    {
    unsigned int cpu = smp_processor_id();

    - if (cpu_is_offline(cpu) ||
    + if (arch_cpu_is_offline(cpu) ||
    (crashing_cpu != -1 && crashing_cpu != cpu)) {
    u64 mcgstatus;

    --- a/arch/x86/kernel/nmi.c
    +++ b/arch/x86/kernel/nmi.c
    @@ -478,7 +478,7 @@ static DEFINE_PER_CPU(unsigned long, nmi

    DEFINE_IDTENTRY_NMI(exc_nmi)
    {
    - if (IS_ENABLED(CONFIG_SMP) && cpu_is_offline(smp_processor_id()))
    + if (IS_ENABLED(CONFIG_SMP) && arch_cpu_is_offline(smp_processor_id()))
    return;

    if (this_cpu_read(nmi_state) != NMI_NOT_RUNNING) {
    --- a/include/linux/cpumask.h
    +++ b/include/linux/cpumask.h
    @@ -888,7 +888,20 @@ static inline const struct cpumask *get_
    return to_cpumask(p);
    }

    -#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
    +#if NR_CPUS > 1
    +static __always_inline bool arch_cpu_online(int cpu)
    +{
    + return arch_test_bit(cpu, cpumask_bits(cpu_online_mask));
    +}
    +#else
    +static __always_inline bool arch_cpu_online(int cpu)
    +{
    + return cpu == 0;
    +}
    +#endif
    +
    +#define arch_cpu_is_offline(cpu) unlikely(!arch_cpu_online(cpu))
    +#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))

    #if NR_CPUS <= BITS_PER_LONG
    #define CPU_BITS_ALL \

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      Last update: 2020-06-03 13:45    [W:7.333 / U:0.020 seconds]
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