Messages in this thread Patch in this message | | | Date | Wed, 03 Jun 2020 13:40:23 +0200 | From | Peter Zijlstra <> | Subject | [PATCH 9/9] x86/entry, cpumask: Provide non-instrumented variant of cpu_is_offline() |
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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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