static int nmi_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs) { if (nmi_cpu_backtrace(regs)) return NMI_HANDLED; return NMI_DONE; }
/* * When raise() is called it will be passed a pointer to the * backtrace_mask. Architectures that call nmi_cpu_backtrace() * directly from their raise() functions may rely on the mask * they are passed being updated as a side effect of this call. */ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self, void (*raise)(cpumask_t *mask)) { int i, this_cpu = get_cpu(); if (test_and_set_bit(0, &backtrace_flag)) { /* * If there is already a trigger_all_cpu_backtrace() in progress * (backtrace_flag == 1), don't output double cpu dump infos. */ put_cpu(); return; } cpumask_copy(to_cpumask(backtrace_mask), mask); if (exclude_self) cpumask_clear_cpu(this_cpu, to_cpumask(backtrace_mask)); /* * Don't try to send an NMI to this cpu; it may work on some * architectures, but on others it may not, and we'll get * information at least as useful just by doing a dump_stack() here. * Note that nmi_cpu_backtrace(NULL) will clear the cpu bit. */ if (cpumask_test_cpu(this_cpu, to_cpumask(backtrace_mask))) nmi_cpu_backtrace(NULL); if (!cpumask_empty(to_cpumask(backtrace_mask))) { pr_info("Sending NMI from CPU %d to CPUs %*pbl:\n", this_cpu, nr_cpumask_bits, to_cpumask(backtrace_mask)); raise(to_cpumask(backtrace_mask)); } /* Wait for up to 10 seconds for all CPUs to do the backtrace */ for (i = 0; i < 10 * 1000; i++) { if (cpumask_empty(to_cpumask(backtrace_mask))) break; mdelay(1); touch_softlockup_watchdog(); } /* * Force flush any remote buffers that might be stuck in IRQ context * and therefore could not run their irq_work. */ printk_nmi_flush(); clear_bit_unlock(0, &backtrace_flag); put_cpu(); }
static void handle_backtrace_ipi(struct pt_regs *regs) { nmi_cpu_backtrace(regs); }