diff options
| -rw-r--r-- | lib/nmi_backtrace.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c index 8abe1870dba4..dae233c5f597 100644 --- a/lib/nmi_backtrace.c +++ b/lib/nmi_backtrace.c @@ -92,17 +92,24 @@ module_param(backtrace_idle, bool, 0644); bool nmi_cpu_backtrace(struct pt_regs *regs) { int cpu = smp_processor_id(); + unsigned long flags; if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) { if (!READ_ONCE(backtrace_idle) && regs && cpu_in_idle(instruction_pointer(regs))) { pr_warn("NMI backtrace for cpu %d skipped: idling at %pS\n", cpu, (void *)instruction_pointer(regs)); } else { + /* + * Allow nested NMI backtraces while serializing + * against other CPUs. + */ + printk_cpu_lock_irqsave(flags); pr_warn("NMI backtrace for cpu %d\n", cpu); if (regs) show_regs(regs); else dump_stack(); + printk_cpu_unlock_irqrestore(flags); } cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask)); return true; |