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| author | Peter Zijlstra <peterz@infradead.org> | 2020-06-03 13:32:48 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-06-15 14:10:09 +0200 |
| commit | 14d3b376b6c3f66d62559d457d32edf565472163 (patch) | |
| tree | 0978931489a631b4fbf43cacad276d66642f113c /arch/x86 | |
| parent | compiler_types.h: Add __no_sanitize_{address,undefined} to noinstr (diff) | |
| download | linux-14d3b376b6c3f66d62559d457d32edf565472163.tar.xz linux-14d3b376b6c3f66d62559d457d32edf565472163.zip | |
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>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/cpumask.h | 18 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mce/core.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/nmi.c | 2 |
3 files changed, 20 insertions, 2 deletions
diff --git a/arch/x86/include/asm/cpumask.h b/arch/x86/include/asm/cpumask.h index 6722ffcef2e6..3afa990d756b 100644 --- a/arch/x86/include/asm/cpumask.h +++ b/arch/x86/include/asm/cpumask.h @@ -11,5 +11,23 @@ extern cpumask_var_t cpu_sibling_setup_mask; extern void setup_cpu_local_masks(void); +/* + * NMI and MCE exceptions need cpu_is_offline() _really_ early, + * provide an arch_ special for them to avoid instrumentation. + */ +#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)) + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_CPUMASK_H */ diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index ce9120c4f740..fbe89a92ff36 100644 --- 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_cpu(void) { 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; diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 2de365f15684..d7c5e44b26f7 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -478,7 +478,7 @@ static DEFINE_PER_CPU(unsigned long, nmi_dr7); DEFINE_IDTENTRY_RAW(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) { |